Air Force Aerial Refueling Methods: Flying Boom versus Hose-and-Drogue
Mike
Congressional Research Service ˜ The Library of Congress
CRS Report for Congress
Order Code RL32910
Air Force Aerial Refueling Methods:
Flying Boom versus Hose-and-Drogue
Updated June 5, 2006
Christopher Bolkcom
Specialist in National Defense
Foreign Affairs, Defense, and Trade Division
Air Force Aerial Refueling Methods:
Flying Boom versus Hose-and-Drogue
Summary
Decisions on the composition of the Air Force aerial refueling fleet
were made
decades ago, when the primary mission was to refuel long-range
strategic bombers.
Modifications have been made to many of these tanker aircraft (KC-135s
and KC-
10s) to make them more effective in refueling fighter aircraft. This
report, which will
be updated, examines the balance between two different refueling
methods in today's
refueling fleet - "flying boom" and "hose-and-drogue."
Contents
Introduction 1
Background 2
Effectiveness of the Current Air Force Fleet 3
Potential Issues 6
List of Figures
Figure 1. USAF KC-10 Refueling B-52 with Flying Boom 1
Figure 2. USMC KC-130 Refueling F/A-18s with Hose-and-Drogue 2
Figure 3. Current and Hypothetical Air Force Aerial Refueling Profiles
5
Air Force Aerial Refueling Methods:
Flying Boom versus Hose-and-Drogue
Introduction
Air Force aerial refueling received considerable attention in the 108th
and 109th
Congresses. Much attention has focused on recapitalizing the KC-135
fleet, and a
proposed - and ultimately rejected - lease of 100 Boeing KC-767
aircraft.1 In light of
proposed replacements to the tanker fleet, this report examines the
Department of
Defense's (DOD) mix of aerial refueling methods.
Currently, Air Force fixed-wing aircraft refuel with the "flying
boom." The boom
is a rigid, telescoping tube that an operator on the tanker aircraft
extends and inserts into
a receptacle on the aircraft being refueled.
Air Force helicopters, and all Navy and Marine Corps aircraft refuel
using the "hose-anddrogue."
NATO countries and other allies also refuel with the hose-and drogue.
As its
name implies, this refueling method employs a flexible hose that trails
from the tanker
aircraft. A drogue (a small windsock) at the end of the hose stabilizes
it in flight, and
provides a funnel for the aircraft being refueled, which inserts a
probe into the hose.
All boom-equipped tankers (i.e., KC-135, KC-10), have a single boom and
can refuel one aircraft at a time with this mechanism. Many tanker
aircraft that employ
the hose-and-drogue system, can simultaneously employ two such
mechanisms - and,
refuel two aircraft simultaneously. The boom, however, can dispense
fuel faster than a
hose-and-drogue.
A single flying boom can transfer fuel at approximately 6,000 lbs per
minute. A
single hose-and-drogue can transfer between 1,500 and 2,000 lbs of fuel
per minute.
Unlike bombers and other large aircraft, however, fighter aircraft
cannot accept fuel at the
boom's maximum rate. (Today's fighter aircraft can accept fuel at
1,000 to 3,000 lbs per
minute whether from the boom or from the hose-and-drogue.)2 Thus, the
flying boom's
primary advantage over the hose-and-drogue system is lost when
refueling fighter aircraft.
As decisions are made regarding the Air Force tanker fleet, an issue
that may arise
for Congress is whether to examine the mix of boom, and
hose-and-drogue-refuelable
aircraft in the Air Force. What might be the benefits and costs of any
changes? Would
DOD benefit in terms of increased combat power? If so, would this
benefit justify the
cost?
Background
Air Force aircraft have not always used the flying boom. All U.S.
combat aircraft
used the hose-and-drogue system until the late 1950s. The Air Force's
decision to field
boom-equipped tankers was based on the refueling needs of long-range
bombers, which
required large amounts of fuel. The Air Force's fighter community
resisted eliminating
the hose-and-drogue, but was overruled by the Strategic Air Command,
which operated
the tanker fleet, and during the Cold War, placed a higher value on
refueling bombers.3
The perceived shortcomings of using a single boom to refuel fighter
aircraft is
reflected in a 1990 Air Force initiative to standardize DOD fighter
aircraft refueling on
the hose-and-drogue method. As initially conceived, the initiative
consisted of three
elements: (1) placing probes on all F-15 and F-16 fighters; (2)
incorporating a probe in
the design of the F-22A; and (3) adding two drogue pods to at least 150
KC-135s. To
provide redundancy and flexibility, Air Force fighters would retain
their boom
receptacles.4 The 1991 war with Iraq (Operation Desert Storm)
heightened DOD
concerns over a lack of uniformity in aerial refueling methods. Navy
leaders expressed
frustration and dissatisfaction with the number of Air Force aerial
refueling aircraft
capable of employing the hose-and-drogue. Post-conflict analyses
recommended that the
Navy purchase its own fleet of land-based KC-10-sized tankers to
increase the number
of hose-and-drogue aircraft and reduce its reliance on Air Force aerial
refueling.5
Navy concerns were mollified by Air Force promises of increased
cooperation and
undermined by a lack of budget to purchase new refueling aircraft.6 The
Air Force's hoseand-
drogue initiative was also scaled back. Instead of pursuing the three
elements
described above, the Air Force equipped 20 KC-135s and 20 KC-10s with
Multi Point
Refueling System (MPRS) kits that allow them to employ hose-and-drogue
systems,
either from wing pods, or attached to the end of the boom.
Effectiveness of the Current Air Force Fleet
The Air Force's aerial refueling fleet is often described as a
"high demand/low
density" (HD/LD) force. The fleet is in high demand because of the
operational benefit
derived from aerial refueling, the long distances U.S. combat aircraft
often must fly, and
the multiple operations in which they are engaged. Despite numbering
well over 500
aircraft, the fleet is considered low density (few in number) for two
apparent reasons.
First, the demand for hose-and-drogue refueling across DOD does not
appear to be
well matched by the Air Force's hose-and-drogue capabilities; this
can create a refueling
bottleneck. As some have observed, "Operation Desert Storm, Operation
Allied Force in
1999 over Yugoslavia, and Operation Enduring Freedom in 2001
demonstrated that
requests for fuel offload do not always match the capacity to deliver
it."7 It appears that
limited access to Air Force tankers has handicapped or complicated the
Navy's longrange
strike capability in some conflicts. Because KC-135 aircraft employ a
single hose,
Navy fighters must cycle six to eight aircraft through the refueling
queue. By the time the
last aircraft has refueled, the first one requires more gas. This
process can require three
to four refueling hits for each aircraft before reaching a distant
target. Navy and Marine
Corps strike packages - often composed of 24 aircraft - have
required as many as four
KC-135s to meet their refueling needs.8 Suggesting a dearth of Air
Force tanker support,
U.S. Navy pilots who flew early missions against the Taliban during
Operation Enduring
Freedom described the UK Royal Air Force's (RAF) six VC-10 tankers
that supported
them as "a Godsend" and the "silent heros" of the air war. Navy
pilots expressed a clear
preference for RAF tankers over USAF tankers.9
To ameliorate a deficit in refueling assets during Operation Iraqi
Freedom, the Navy
flew refueling sorties with F/A-18E/F aircraft.10 While using the Super
Hornet for aerial
refueling demonstrated flexibility and reduced the Navy's dependence
on the Air Force
for refueling, these desirable attributes came at a cost. F/A-18E/F
aircraft, and the pilots
that fly them, are very specialized. Using these assets for aerial
refueling rather than
combat is seen as a sub-optimization of a scarce and valuable resource.
F/A-18E/F
squadron VFA-115 flew 623 sorties between March 21, 2003 and April 9,
2003: 216 were
refueling sorties. When equipped to refuel other aircraft, Super
Hornets carry only self
defense weapons and are not equipped to conduct attack operations.11
The second reason the 500+ aircraft tanker fleet is considered "low
density" is that
it does not appear that the flying boom's fuel transfer rate is fully
taken advantage of,
leading to an under-exploitation of the tanker fleet by most Air Force
aircraft. In 2005,
96% of Air Force aircraft that are aerial refuelable use the flying
boom. However, only
20% of the current Air Force fleet (669 bombers and surveillance
aircraft of 3,227
aircraft) can use the refueling boom to its full capacity. Four percent
of the Air Force fleet
(139 helicopters of 3,227 aircraft) can't use the boom at all.
Seventy four percent of the
fleet (2,419 fighters of 3,227 aircraft) could potentially refuel with
the hose-and-drogue
with no reduction in fuel transfer rates.12
The following two scenarios illustrate the potentially more effective
exploitation of
aerial refueling assets by Air Force aircraft. If the Air Force were to
replace its 1,356 F-
16s and 356 A-10s (which are outfitted with boom receptacles) with
1,763 JSFs that are
equipped to refuel with refueling probes, only 43% of the fleet (1,470
of 3,372 aircraft)
would need to be refueled with booms. (The black and black-and-white
columns in
Figure 3). Air Force boom-refuelable aircraft would be evenly divided
between large
aircraft that can use this method at its full transfer rate and small
aircraft that use the
boom at a reduced transfer rate.
The Air Force wishes to replace its 722 F-15s, and 55 F-117s (777
total) with the F-
22A Raptor. It too could potentially be modified to refuel with
hose-and-drogue systems.
Because the F-22 design is more mature than that of the JSF, changes to
the aircraft to
convert it from boom to hose-and-drogue refueling may be more expensive
and
potentially infeasible. The Air Force wants 381 Raptors. The current
budget plan
supports the purchase of 179 F-22As.13 If the Air Force were to modify
the F-22A to
refuel by the hose-and-drogue method and if the Air Force were to
replace its 777 legacy
aircraft with 381 Raptors, the percentage of the total fleet that would
require boom
refueling would drop to 23% (669 of 2,932 aircraft). All these aircraft
use the boom at
its full transfer rate. Seventy-seven percent of the fleet (2,243 of
2,912 aircraft) would use
the hose-and-drogue refueling system and be interoperable with Navy,
Marine Corps and
allied refueling aircraft.14
Potential Issues
Considering changes to the mix of refueling methods in the Air Force
tanker fleet
appears to raise two overarching issues: potential operational benefit
and potential cost.
The primary potential operational benefit of increasing the number of
aerial refueling
hoses has already been described above: a more effective use of aerial
refueling assets.
Another potential benefit of increasing the number of aerial refueling
hoses may include
greater interoperability and thus more effective coordination among the
Air Force, Navy,
Marine Corps, and allied air forces.
Calculating the potential costs of increasing the proportion of hoses
to booms in the
Air Force tanker fleet would depend in large part on how DOD and
Congress might
decide to recapitalize and upgrade the current fleet. One option would
be to replace the
oldest KC-135s with new aircraft equipped with two refueling hoses.
Structural
modifications to commercial aircraft to accommodate a flying boom are
more significant
than the modifications for hose-and-drogue mechanisms. The boom itself
also costs more
than the hose-and-drogue and is more complex. Thus, these new aircraft
would likely be
less costly than new, boom-equipped tankers. Newer KC-135s and KC-10s
with booms
would need to be retained to refuel large aircraft.
Another option would be to replace the oldest KC-135s with new,
boom-equipped
tankers and to outfit the remaining tankers with the Multipoint
Refueling System (MPRS).
Estimates by the GAO and CRS suggest that the cost of producing and
installing the
MPRS could be roughly $5.1 million per aircraft in 2004 dollars or $510
million for 100
aircraft. (Air Force program officials estimate it takes approximately
7,000 man-hours,
or up to seven months, to modify KC-135s to accept the MPRS.)15 This
cost estimate
does not consider newer systems being developed that could be more or
less expensive
than MPRS.16
Regardless of which approach is taken to recapitalize the KC-135 fleet,
legacy USAF
fighter aircraft would need to be retrofitted, and new aircraft would
need to be
manufactured with refueling probes if they were to exploit multipoint
hose-and-drogue
refueling. It may be that the costs incurred by these modifications
could be offset by the
cost savings derived from improved aerial refueling effectiveness and
corresponding
reductions in tanker force structure. "According to 1991 Air Force
estimates, the $1.3
billion cost to modify about 3,000 F-15 and F-16 fighter and 250
tankers [to hose-anddrogue
configuration] could be offset by reduced operating and support costs
from the
retirement of about 26 KC-135 tankers."17
At least five studies have examined the pros and cons of a single boom
versus
multipoint hose-and-drogues.18 Because these studies considered
different operational
factors in their analyses and made different assumptions, they came to
different
conclusions. However, all found that tankers equipped with multipoint
hose-and-drogue
refueling would refuel combat aircraft more effectively than boom
equipped aircraft and
could therefore allow a reduction in the tanker fleet. Reduction
estimates ranged from
17% to 50%.19 These reductions would result from the increased speed
with which a
multipoint hose-and-drogue-equipped aircraft could refuel
multiple-aircraft strike
packages. The following evaluation illustrates how increasing the speed
with which
combat aircraft are refueled could translate into increased efficiency
and potentially lead
to reduced tanker force structure and cost savings:
by refueling two fighters simultaneously, the time that the fighters
spend refueling can
be reduced by approximately 75 percent. This reduced refueling time, in
turn, would
enable the tanker to have considerably more fuel available to off-load
to other
receivers....The less fuel burned by either the tanker or the receivers
during aerial
contact, the more that is available to conduct the fighter mission. At
fighter refueling
speeds, a KC-135A burns something in excess of 200 pounds per minute.
Reducing
the air refueling time from 40 minutes to 10 minutes (75 percent) makes
approximately 6,000 pounds of additional fuel available....the fuel
savings in a fourtanker
formation could be enough to refuel an extra flight of four fighters or
allow the
same mission to be accomplished with one less tanker.20
Advocates of the flying boom argue that it is prudent to maintain a
large number of
these tankers in the Air Force. While fighter aircraft receive much
media attention, the
contribution of long-range bombers to recent conflicts has been
noteworthy.21 These
aircraft may become even more important as the United States reduces
its overseas basing
and deploys over greater distances. Bombers and other large aircraft
can spend as much
as 20 minutes refueling at the boom's maximum capacity. Refueling
such aircraft with
the hose-and-drogue is infeasible.22
Further, boom advocates argue, technological advances are being made in
new
booms which reduce operator workload and should make them safer and
more reliable
than the hose-and-drogue method.23 Industry is incorporating
commercial, off-the-shelf
technology in booms currently under development, hoping to make them
"fail safe."24
Finally, it is argued, tankers with flying booms are in some ways more
flexible than
tankers with hose-and-drogue refueling. A tanker with a flying boom can
be converted
in the field to accommodate probe-equipped aircraft, if necessary.
Hose-and-drogue
tankers cannot be converted to accommodate aircraft with boom
receptacles. To
accommodate fighter aircraft, tankers with flying booms can reduce the
speed at which
they dispense fuel.25 Tankers with hose-and-drogue refueling cannot
increase the speed
at which they dispense fuel to accommodate bombers and other large
aircraft.
1 See CRS Report RL32056. The Air Force KC-767 Tanker Lease Proposal:
Key Issues For
Congress for more information.
2 KC-135 Aerial Refueling Manual T.O. 1-1C-1-3.
3 For more information on ths history of air refueling, see
[http://www.centennialofflight.gov/essay/Evolution_of_Technology/refueling/Tech22.htm].
4 "Multipoint Refueling Planned for Air Force KC-135 Fleet,"
Aerospace Daily, Mar. 12,
1991, p. 420 and Government Accounting Office, Aerial Refueling
Initiative: Cross-Service
Analysis Needed to Determine Best Approach, GAO/NSIAD-93-186, July
1993, p. 7.
5 "Navy Sees Need for Organic Land-Based Tankers, More Satellites,"
Aerospace Daily,
May 10, 1991.
6 "Navy/Air Force Deal Would Eliminate Navy Need for Large
Tankers," Aerospace Daily.
Sept. 25, 1991.
7 Hunter Keeter, "Naval Air Refueling Needs Deferred in Air Force
Tanker Plan," Sea
Power, Apr. 2004.
8 Ibid.
9 David Graves, "Britain's Flying Tankers Hailed as
'Godsend,'" London Daily Telegraph,
Nov. 10, 2001.
10 David Fulghum, "Tanker Puzzle," Aviation Week & Space
Technology, Apr. 14, 2003.
P.23.
11 USN Office of Legislative Affairs, telephone conversation with CRS,
Apr. 13, 2004.
12 Refuelable Aircraft Inventory, (Excel Spreadsheet) USAF Office of
Legislative Liaison,
Weapons Division, Apr. 12, 2005.
13 See CRS Report RL31673, F-22A Raptor, by Christopher Bolkcom.
14 This analysis assumes no changes to other aircraft in the Air Force
fleet. If the number
of long-range bombers, strategic airlift aircraft, and aerial refueling
aircraft (capable of
being refueled themselves), increases in the future, the percentage of
aircraft most in need
of boom refueling would also increase.
15 Michael Gething, "KC-135 Upgrades Continue Apace," International
Defense Review,
May 14, 1999.
16 GAO/NSIAD-96-160, estimated that the Air Force would spend $204
million to equip 45
KC-135s with MPRS. On January 27, 1997, Boeing received a $23 million
contract to
fabricate nine kits to convert nine KC-135Rs to the MPRS configuration.
On December 20,
1997, Boeing was awarded a $15.5 million "face value increase" to
the MPRS contract.
$38.5 million / 9 MPRS kits = $4.2 million per MPRS in 1997 dollars. To
account for
inflation, a DOD deflator of 1.2156 was used. 1.2156 x $4.2 million =
$5.1 million in 2004
dollars. On July 1, 1996, the Air Force awarded a contract to Boeing
for $8.7 million for two
MPRS ship-sets. Using the same deflator to account for inflation, this
equates to $5.3
million per MPRS ship-set in FY2004 dollars.
17 GAO/NSIAD-93-186, op. cit.
18 Enhancing USAF Aerial Refueling Capabilities, RAND, 1990; Utility of
KC-135
Multipoint Modifications, AFSAA, 1992; Impact of Multipoint/Receptacle
Modifications,
AMC/XPY, 1993; Aerial Refueling Initiative, GAO, 1993; Multipoint
Refueling Program
Cost Benefit Analysis, Frontier Technology, 1995.
19 Paul Killingsworth. Multipoint Aerial Refueling: A Review and
Assessment. RAND, 1996,
pp. vii-ix.
20 Maj. Marck R. Cobb, "Aerial Refueling: The Need for a Multipoint,
Dual-System
Capability," AU-ARI-CP-87-3, Air University Press, July 1987.
21 See CRS Report RL31544, Long-Range Bombers: Background and Issues
for Congress.
22 CRS interviews with Air Force aerial refueling personnel, Sept. 2004
- Mar. 2005.
23 See, for example, David A. Fulghum, "Lowering the Boom,"
Aviation Week & Space
Technology, Feb. 7, 2005.
24 Lisa Troshinsky, "EADS' aerial refueling boom to be lightweight,
fail-safe," Aerospace
Daily and Defense Report, Sept. 15, 2004
25 KC-135 Aerial Refueling Manual T.O. 1-1C-1-3.
Kevin Brooks
"Mike" <yard...@yahoo.com> wrote in message
news:1151524373.8...@x69g2000cwx.googlegroups.com...
> the experts at work
<snip>
>Air Force helicopters, and all Navy and Marine Corps aircraft refuel
>using the "hose-anddrogue."
Not "all" USN aircraft; the E-6 Mercury TACAMO's use the boom.
>NATO countries and other allies also refuel with the hose-and drogue.
F-16 users don't. Which is why Singapore and Turkey both have boom
refueling. As do the new Japanese 767 tankers destined to support their
F-15J's, F-2's, etc.
<snip>
> All boom-equipped tankers (i.e., KC-135, KC-10), have a single boom and
> can refuel one aircraft at a time with this mechanism.
Unless, like some KC-135s/KC-10's, they *also* have multi-point
hose-and-drogue capability.
> Many tanker
> aircraft that employ
> the hose-and-drogue system, can simultaneously employ two such
> mechanisms - and,
> refuel two aircraft simultaneously.
As can a lot of boom tankers when using the hose/drogue underwing pods in
combo with their boom-mounted drogue; I belive they can actually handle up
to *three* simultaneous receivers (at least the KC-10's can).
This CNS clown has already gotten a lot of details wrong (and one would
expect the details to be *right* in such a potentially policy-influencing
work); one wonders how he addresses the little fact that the boomers have
the versatility to handle hose and drogue receivers, while the hosers can't
do anything but wave at a receiver that has the boom recepticle? And what of
the requirement (which won't go away) to refuel the larger aircraft (i.e.,
B-1B, B-52, B-2, C-5, C-17, E-8, RC-135, etc.) that can indeed still use the
full greater capacity of the boom unit?Enough of his rant.
Brooks
<snip>
Curt
Flying Boom versus Hose-and-Drogue
Updated June 5, 2006
Christopher Bolkcom
Specialist in National Defense
Foreign Affairs, Defense, and Trade Division
This is mostly crap. When the AF was set to buy 767 tankers it was taken
for granted that they would be equipped with not only the boom but a pair of
hose & drogue pods. Then it was felt that money could be saved by
eliminating the pods, so the accountants got busy trying to prove that they
were not that effective, to the point of lying amount pod failure rates.
When SAF Roche suddenly decided the AF would buy the STOVL F-35, it had to
be the same as the USMC version, complete with probe. So then the same
accountants got busy trying to prove that hose & drogue was better, which is
where I suspect this study came from (note that it was recently updated).
"Thus, the flying boom's primary advantage over the hose-and-drogue system
is lost when refueling fighter aircraft."
Nonsense. A boom can still push fuel to a fighter faster than a hose. Just
because it is not operating at capacity does not mean it is lost.
"All U.S. combat aircraft used the hose-and-drogue system until the late
1950s."
Nonsense. Guess they didn't know about KB-29s refueling RB-45s during the
Korean War, or all the other work with fighters. And I guess the B-47 and
B-52 were not combat aircraft either.
"NATO countries and other allies also refuel with the hose-and drogue."
Guess they missed all the export F-16s, F-4s, F-15s, F-111s, etc. that
refuel with the boom. Guess that is why Australia, Brazil, Italy, Japan,
Israel, The Netherlands and Saudi Arabia all operate (or will soon operate)
boom tankers. Did I miss any?
"Unlike bombers and other large aircraft, however, fighter aircraft cannot
accept fuel at the boom's maximum rate. (Today's fighter aircraft can accept
fuel at 1,000 to 3,000 lbs per minute whether from the boom or from the
hose-and-drogue.)2 Thus, the flying boom's primary advantage over the
hose-and-drogue system is lost when refueling fighter aircraft."
Nonsense. Actually bombers and airlifters usually cannot accept fuel at the
max rate, as flow decreases as their tanks become full. Isn't it smarter to
have a boom that can put out more than required, rather than the other way
around, as with a hose?
"Navy leaders expressed frustration and dissatisfaction with the number of
Air Force aerial refueling aircraft capable of employing the
hose-and-drogue."
Okay, so put pods on USAF tankers. Cheaper and easier than putting
less-effective probes on all AF fighters. The next tanker should come
factory equipped.
"While using the Super Hornet for aerial refueling demonstrated flexibility
and reduced the Navy's dependence on the Air Force for refueling, these
desirable attributes came at a cost. F/A-18E/F aircraft, and the pilots that
fly them, are very specialized. Using these assets for aerial
refueling rather than combat is seen as a sub-optimization of a scarce and
valuable resource."
No shit, really? Maybe they should have kept a few S-3s around. Regardless,
it is still cheaper and easier to pod USAF tankers than probing all AF
fighters.
"However, only 20% of the current Air Force fleet (669 bombers and
surveillance aircraft of 3,227 aircraft) can use the refueling boom to its
full capacity."
So, let's convert to a system that is less capable. That way 100% of the
current Air Force fleet would use the hose to its full capacity.
"Four percent of the Air Force fleet (139 helicopters of 3,227 aircraft)
can't use the boom at all."
'Course, what they forget to mention is that those 139 helos cannot refuel
from a KC-10 or a KC-135 anyway, so yet another meaningless statistic.
"Seventy four percent of the fleet (2,419 fighters of 3,227 aircraft) could
potentially refuel with the hose-and-drogue with no reduction in fuel
transfer rates."
Except that refueling is slower through the hose so yes, they would suffer a
reduction.
"...technological advances are being made in new booms which reduce operator
workload and should make them safer and more reliable
than the hose-and-drogue method."
Safer and more reliable? Dudes, anyone who has ever watched air refueling
with both the hose and boom know that boom refueling is already much more
reliable and safer than hose refueling. The MTBF of the boom is many times
that of a drogue. Further, if a boom has a problem it can still be stowed
and brought back for repair. OTOH, a hose malfunction frequently means
jettisoning the hose. Ask ANY KC-135 or KC-10 crewmember which is safer and
more reliable. Throw in some rough air, stress, battle damage, and hose
refueling difficulties increase enormously.
"Finally, it is argued, tankers with flying booms are in some ways more
flexible than tankers with hose-and-drogue refueling. A tanker with a flying
boom can be converted in the field to accommodate probe-equipped aircraft,
if necessary. Hose-and-drogue tankers cannot be converted to accommodate
aircraft with boom receptacles."
No small point, and not just in the field. Modifying an existing airplane to
carry pods is much easier than adding a boom.
One last factor this study completely fails to address is cycle times. A
receptacle-equipped receiver can get a contact faster than one that is
probe-equipped. The study seems to assume that a tanker with two hoses can
refuel twice as many receivers in a given period than a boom tanker. Tain't
so. Of course my math may need a refresher because even if they could, the
study's numbers don't add up. It also assumes there will be an even amount
of receivers (2, 4, 6, etc.). Throw in a extra (odd) receiver, or just a
single receiver, and now one of those pods will be idle.
Christopher Bolkcom may be a Specialist in National Defense, but he is not a
tanker person. Or maybe he's just a hired gun, trying to justify a
pre-conceived conclusion. The obvious solution is to put pods on more USAF
tankers, or purchase more KC-130s for the USMC. And (don't laugh) there are
a number of proposals to mount booms on tankers' wings, allowing multiple
receptacle refuelings. McDonnell Douglas wanted to do it years ago with the
MD-11 but there was no money.
Curt
Duncan Riddle
> "Mike" <yard...@yahoo.com> wrote in message
> news:1151524373.8...@x69g2000cwx.googlegroups.com...
>
>
>>the experts at work
>
>
> <snip>
>
>>Air Force helicopters, and all Navy and Marine Corps aircraft refuel
>>using the "hose-anddrogue."
>
>
> Not "all" USN aircraft; the E-6 Mercury TACAMO's use the boom.
>
>
>>NATO countries and other allies also refuel with the hose-and drogue.
>
>
> F-16 users don't. Which is why Singapore and Turkey both have boom
> refueling. As do the new Japanese 767 tankers destined to support their
> F-15J's, F-2's, etc.
>
The statement doesn't say that NATO etc exclusively use hose-and-drogue.
You picked up the real error in your E-6 comment.
> <snip>
>
>>All boom-equipped tankers (i.e., KC-135, KC-10), have a single boom and
>>can refuel one aircraft at a time with this mechanism.
>
>
> Unless, like some KC-135s/KC-10's, they *also* have multi-point
> hose-and-drogue capability.
>
They can still only fuel one aircraft from the boom at a time.
>
>>Many tanker
>>aircraft that employ
>>the hose-and-drogue system, can simultaneously employ two such
>>mechanisms - and,
>>refuel two aircraft simultaneously.
>
>
> As can a lot of boom tankers when using the hose/drogue underwing pods in
> combo with their boom-mounted drogue; I belive they can actually handle up
> to *three* simultaneous receivers (at least the KC-10's can).
I believe he does mention this further in the article.
>
> This CNS clown has already gotten a lot of details wrong (and one would
> expect the details to be *right* in such a potentially policy-influencing
> work); one wonders how he addresses the little fact that the boomers have
> the versatility to handle hose and drogue receivers, while the hosers can't
> do anything but wave at a receiver that has the boom recepticle?
Near the end of the article this is addressed.
Can I ask a question here (well, two, if you count this one)? Could a
KC135/KC10 with a boom-mounted drogue still refuel a B52? If it can't
then a boomer without MPRS will be waving at probe-only receivers. (The
article says that a boom tanker can have a field conversion to handle
drogue, but doesn't detail whether this is by fitting a USN buddy store,
or by doing something to the boom.)
> And what of
> the requirement (which won't go away) to refuel the larger aircraft (i.e.,
> B-1B, B-52, B-2, C-5, C-17, E-8, RC-135, etc.) that can indeed still use the
> full greater capacity of the boom unit?
That's addressed (reformatted for clarity):
<quote>
One option would be to replace the oldest KC-135s with new aircraft
equipped with two refueling hoses. Structural modifications to
commercial aircraft to accommodate a flying boom are more significant
than the modifications for hose-and-drogue mechanisms. The boom itself
also costs more than the hose-and-drogue and is more complex. Thus,
these new aircraft would likely be less costly than new, boom-equipped
tankers. Newer KC-135s and KC-10s with booms would need to be retained
to refuel large aircraft.
Another option would be to replace the oldest KC-135s with new,
boom-equipped tankers and to outfit the remaining tankers with the
Multipoint Refueling System (MPRS).
</quote>
To summarise -
Option 1 - keep the newer boom tankers, scrap the old ones, buy new
hose- tankers because they're cheaper than buying new boom tankers. This
leaves you with both boom tankers and hose tankers.
Option 2 - scrap the oldest tankers, convert the rest to MPRS (both boom
and hose), buy new boom tankers.
(For some reason, I'm not spotting the suggestion that new-buy tankers
should come with both booms _and_ hoses. Wouldn't it be cheaper to plumb
them up from new?)
Anyhow - in both cases you've still got booms to refuel the heavies.
> Enough of his rant.
>
Where would we be without a good rant now and then? :-)
> Brooks
>
--
Duncan.
Kevin Brooks
"Duncan Riddle"
<duncan.getrido...@btinternet.andthisbitaswell.com> wrote in
message news:99ednZ5g1v2NUD7Z...@bt.com...
> Kevin Brooks wrote:
>> "Mike" <yard...@yahoo.com> wrote in message
>> news:1151524373.8...@x69g2000cwx.googlegroups.com...
>>
>>
>>>the experts at work
>>
>>
>> <snip>
>>
>>>Air Force helicopters, and all Navy and Marine Corps aircraft refuel
>>>using the "hose-anddrogue."
>>
>>
>> Not "all" USN aircraft; the E-6 Mercury TACAMO's use the boom.
>>
>>
>>>NATO countries and other allies also refuel with the hose-and drogue.
>>
>>
>> F-16 users don't. Which is why Singapore and Turkey both have boom
>> refueling. As do the new Japanese 767 tankers destined to support their
>> F-15J's, F-2's, etc.
>>
>
> The statement doesn't say that NATO etc exclusively use hose-and-drogue.
It makes that inference, as it does not mention anything about the fact that
some NATO countries do indeed use booms. In fact, if you compare the actual
real tanker inventories of the European NATO nations (only a handful have
such systems of any tupe), you will find almost as many boom operators as
hose-and-drogue users. I count four users equipped with tankers that have
booms (though I don't think the French use their boomers for anything but
hose/drogue). The hose and drogue users number two or three (or four if you
include the French), not counting those countries that have resorted to the
C-130-as-cheap-tanker-alternative approach. Hardly the situation the writer
described.
> You picked up the real error in your E-6 comment.
>
>
>> <snip>
>>
>>>All boom-equipped tankers (i.e., KC-135, KC-10), have a single boom and
>>>can refuel one aircraft at a time with this mechanism.
>>
>>
>> Unless, like some KC-135s/KC-10's, they *also* have multi-point
>> hose-and-drogue capability.
>>
>
> They can still only fuel one aircraft from the boom at a time.
But they have the versatility to fuel multiple hose users; can you name any
hose refuelers that can do the same for the boom receptacle users?
>
>>
>>>Many tanker
>>>aircraft that employ
>>>the hose-and-drogue system, can simultaneously employ two such
>>>mechanisms - and,
>>>refuel two aircraft simultaneously.
>>
>>
>> As can a lot of boom tankers when using the hose/drogue underwing pods in
>> combo with their boom-mounted drogue; I belive they can actually handle
>> up to *three* simultaneous receivers (at least the KC-10's can).
>
> I believe he does mention this further in the article.
I gave up on his article after reading the first part and its compendium of
errors and false inferences.
>
>
>>
>> This CNS clown has already gotten a lot of details wrong (and one would
>> expect the details to be *right* in such a potentially policy-influencing
>> work); one wonders how he addresses the little fact that the boomers have
>> the versatility to handle hose and drogue receivers, while the hosers
>> can't do anything but wave at a receiver that has the boom recepticle?
>
> Near the end of the article this is addressed.
See above.
>
> Can I ask a question here (well, two, if you count this one)? Could a
> KC135/KC10 with a boom-mounted drogue still refuel a B52?
No, but they *can* (and many do) carry seperate pod mounted hose/drogue
units that can allow them to feed both types on the same sortie.
If it can't
> then a boomer without MPRS will be waving at probe-only receivers. (The
> article says that a boom tanker can have a field conversion to handle
> drogue, but doesn't detail whether this is by fitting a USN buddy store,
> or by doing something to the boom.)
They can add a hose and drogue unit to the end of the boom; a Google image
search will provide you with some decent photos of the arrangement.
>
>> And what of the requirement (which won't go away) to refuel the larger
>> aircraft (i.e., B-1B, B-52, B-2, C-5, C-17, E-8, RC-135, etc.) that can
>> indeed still use the full greater capacity of the boom unit?
>
> That's addressed (reformatted for clarity):
> <quote>
> One option would be to replace the oldest KC-135s with new aircraft
> equipped with two refueling hoses. Structural modifications to commercial
> aircraft to accommodate a flying boom are more significant than the
> modifications for hose-and-drogue mechanisms. The boom itself also costs
> more than the hose-and-drogue and is more complex. Thus, these new
> aircraft would likely be less costly than new, boom-equipped tankers.
> Newer KC-135s and KC-10s with booms would need to be retained to refuel
> large aircraft.
Wonderful plan--you have to have the exact right kind of refuelers available
in area X to handle receiver Y? Doesn't that sound a bit complicated? Better
to have the aircraft capable of handling both kinds of receivers; eases the
task of sortie scheduling, deployment scheduling ("Sorry, but being as you
guys are the only unit we have left capable of handling the booms, you get
to deploy overseas three times as often as other units..."), and strike
operation planning.
>
> Another option would be to replace the oldest KC-135s with new,
> boom-equipped tankers and to outfit the remaining tankers with the
> Multipoint Refueling System (MPRS).
> </quote>
>
> To summarise -
>
> Option 1 - keep the newer boom tankers, scrap the old ones, buy new hose-
> tankers because they're cheaper than buying new boom tankers. This leaves
> you with both boom tankers and hose tankers.
Wow. A mixed force of tankers that requires detailed
deconflicting/scheduling for every operation...not a very wonderful idea
IMO.
>
> Option 2 - scrap the oldest tankers, convert the rest to MPRS (both boom
> and hose), buy new boom tankers.
>
> (For some reason, I'm not spotting the suggestion that new-buy tankers
> should come with both booms _and_ hoses. Wouldn't it be cheaper to plumb
> them up from new?)
Probably, but hey, this is a report from some bureaucrat who probably would
not know a KC-135 from a KC-10 if it ran over him on the runway.
>
> Anyhow - in both cases you've still got booms to refuel the heavies.
The idea of a mixed support force is ridiculous, especially in an era where
the USAF is paying acute attention to trying to stabilize deployment
schedules in an effort to keep retention rates up (and manning the tanker
force will cost more than equipping it).
Brooks
Curt
>> combo with their boom-mounted drogue; I belive they can actually handle
>> up to *three* simultaneous receivers (at least the KC-10's can).
While it is physically possible to refuel three aircraft simultaneously, it
is not allowed as the receiver's wingspans would be too close.
> Can I ask a question here (well, two, if you count this one)? Could a
> KC135/KC10 with a boom-mounted drogue still refuel a B52?
No, however, the KC-10 does not use that boom-mounted drogue contraption
(Boom to Drogue Adaptor, or BDA). It was intended as an interim device but
has stuck around. The AF attempted to mount a fuselage hose unit on
KC-135s, just behind the main gear wells. Apparently it did not work so well
and they stuck with the boom mounted drogue.
The KC-10 has a permanent centerline drogue next to the boom pivot area. So
a Ten can refuel any fixed wing aircraft on a single mission. The KC-135 can
do one or the other but not both.
> Option 1 - keep the newer boom tankers, scrap the old ones, buy new hose-
> tankers because they're cheaper than buying new boom tankers. This leaves
> you with both boom tankers and hose tankers.
Absolutely not; it would be a planner's nightmare having to juggle boom only
vs. hose only tankers. Equip them with both and the problem goes away.
They might be cheaper to buy but operations costs would increase because you
would have to send more tankers to cover all receivers.
> Option 2 - scrap the oldest tankers, convert the rest to MPRS (both boom
> and hose), buy new boom tankers.
> (For some reason, I'm not spotting the suggestion that new-buy tankers
> should come with both booms _and_ hoses. Wouldn't it be cheaper to plumb
> them up from new?)
Much cheaper, even if they bought pods later. And don't forget to go the
KC-10 route and have a fuselage mounted hose/drogue unit along with the
boom. The wing pods are gravy.
Curt
Kevin Brooks
"Curt" <curt...@cox.net> wrote in message
news:M4Zog.115402$Ce1.36118@dukeread01...
>>> As can a lot of boom tankers when using the hose/drogue underwing pods
>>> in combo with their boom-mounted drogue; I belive they can actually
>>> handle up to *three* simultaneous receivers (at least the KC-10's can).
>
> While it is physically possible to refuel three aircraft simultaneously,
> it is not allowed as the receiver's wingspans would be too close.
What does the following photo show? Looks a lot like three F/A-18's hooked
up simultaneously to a KC-10 to me.... I doubt it is done routinely, but
apparently it has been done.
>
>> Can I ask a question here (well, two, if you count this one)? Could a
>> KC135/KC10 with a boom-mounted drogue still refuel a B52?
>
> No, however, the KC-10 does not use that boom-mounted drogue contraption
> (Boom to Drogue Adaptor, or BDA). It was intended as an interim device but
> has stuck around. The AF attempted to mount a fuselage hose unit on
> KC-135s, just behind the main gear wells. Apparently it did not work so
> well and they stuck with the boom mounted drogue.
>
> The KC-10 has a permanent centerline drogue next to the boom pivot area.
> So a Ten can refuel any fixed wing aircraft on a single mission. The
> KC-135 can do one or the other but not both.
Unless it has the MPRS for hose receivers while keeping its boom "intact".
>
>> Option 1 - keep the newer boom tankers, scrap the old ones, buy new hose-
>> tankers because they're cheaper than buying new boom tankers. This leaves
>> you with both boom tankers and hose tankers.
>
> Absolutely not; it would be a planner's nightmare having to juggle boom
> only vs. hose only tankers. Equip them with both and the problem goes
> away. They might be cheaper to buy but operations costs would increase
> because you would have to send more tankers to cover all receivers.
Yep.
Brooks
Kevin Brooks
"Kevin Brooks" <broo...@notyahoo.com> wrote in message
news:tpSdnbx_NIcRADnZ...@adelphia.com...
>
> "Curt" <curt...@cox.net> wrote in message
> news:M4Zog.115402$Ce1.36118@dukeread01...
>>>> As can a lot of boom tankers when using the hose/drogue underwing pods
>>>> in combo with their boom-mounted drogue; I belive they can actually
>>>> handle up to *three* simultaneous receivers (at least the KC-10's can).
>>
>> While it is physically possible to refuel three aircraft simultaneously,
>> it is not allowed as the receiver's wingspans would be too close.
>
> What does the following photo show? Looks a lot like three F/A-18's hooked
> up simultaneously to a KC-10 to me.... I doubt it is done routinely, but
> apparently it has been done.
Me bad, forgot to include the link...
http://www.gf81.com.cn/16/images/air-kc10.jpg
Brooks
tscottme
about a ballpark number 200, 250, 300, 350, 400 kts? I ask because it
appears the F-18s in the photo have some flaps deployed. How does that
tanking speed compare to a cross-country redeploy speed? Do you slow down
to fill up?
--
Scott
Democrats: "We give more aid and comfort to the enemy before 9 a.m. than
most people give all day."
Curt
news:wZidnYuwrImWJTnZ...@comcast.com...
> What kind of airspeeds would one use while refueling? I'm just curious
> about a ballpark number 200, 250, 300, 350, 400 kts? I ask because it
> appears the F-18s in the photo have some flaps deployed. How does that
> tanking speed compare to a cross-country redeploy speed? Do you slow down
> to fill up?
From ATP-56:
http://www.raf.mod.uk/downloads/documents/Pt2/Pt2Ch10Q-UnitedStatesofAmerica.pdf
AFAIK, TO 1-1C-1-33 is not available online.
Boom AAR height band is sea level to 37,000 ft; speed range is 180 to 350
KIAS. Fuselage hose AAR height band is sea level to 35,000 ft; speed range
is 200 to 280 KIAS. Wing pod AAR height band is sea level to 32,000 ft;
speed range is 200 to 325 KIAS.
Each receiver has an optimum speed but it can adjusted for conditions. It
can vary a lot based on the receiver's weight. 280-300 KIAS for fighters is
a good ballpark figure. 275 for heavies. A-10s and C-130s were in the lower
200s, sometimes with the tanker's flaps and/or slats deployed. The F-18s do
not appear to have flaps deployed; there would be no reason for flaps. The
Ten can easily fly at any receiver's AR speed, with a clean wing, at max
weight. The tanker usually has to slow for refueling. The KC-10 refuelled
at 290 KIAS, although we might accelerate up to 310 knots when heavy.
Curt
Curt
>> it is not allowed as the receiver's wingspans would be too close.
>
> What does the following photo show? Looks a lot like three F/A-18's hooked
> up simultaneously to a KC-10 to me.... I doubt it is done routinely, but
> apparently it has been done.
I did say it was physically possible. T.O.1-1C-1-33 specifically prohibits
refueling three receivers simultaneously. In fact, refueling from the
centerline
hose, or boom, and either WARP is prohibited. That pic may have been taken
during the WARP trials, when it was determined that three receivers were
just too close. (It was also determined that the original hose was not long
enough.) I suppose, if some receivers were about to ditch due to a fuel
emergency, the KC-10 crew go ahead and refuel three at a time. I spent 20
years on the KC-10 and never heard of it, outside of the initial trials
work.
This is from the KC-135 section of ATP-56:
Note: Simultaneous refuelling from the centreline BDA and wing tip mounted
MPRS AAR pod(s) is prohibited due to inadequate refuelling envelope
clearance between receiver aircraft.
>> The KC-10 has a permanent centerline drogue next to the boom pivot area.
>> So a Ten can refuel any fixed wing aircraft on a single mission. The
>> KC-135 can do one or the other but not both.
>
> Unless it has the MPRS for hose receivers while keeping its boom "intact".
Obviously.
Curt
Duncan Riddle
> "Duncan Riddle"
> <duncan.getrido...@btinternet.andthisbitaswell.com> wrote in
> message news:99ednZ5g1v2NUD7Z...@bt.com...
>
>>
>>The statement doesn't say that NATO etc exclusively use hose-and-drogue.
>
>
> It makes that inference, as it does not mention anything about the fact that
> some NATO countries do indeed use booms. In fact, if you compare the actual
> real tanker inventories of the European NATO nations (only a handful have
> such systems of any tupe), you will find almost as many boom operators as
> hose-and-drogue users. I count four users equipped with tankers that have
> booms (though I don't think the French use their boomers for anything but
> hose/drogue). The hose and drogue users number two or three (or four if you
> include the French), not counting those countries that have resorted to the
> C-130-as-cheap-tanker-alternative approach. Hardly the situation the writer
> described.
>
Ok. Inference is in the eye of the beholder. Could be that the guy just
went "Hmmm... NATO, let's see that's the limeys and the krauts and some
other guys. The RAF uses hoses, who cares what the Germans use and the
others don't even have airforces..." ;-)
>>><snip>
>>>
>>>>All boom-equipped tankers (i.e., KC-135, KC-10), have a single boom and
>>>>can refuel one aircraft at a time with this mechanism.
>>>
>>>
>>>Unless, like some KC-135s/KC-10's, they *also* have multi-point
>>>hose-and-drogue capability.
>>>
>>
>>They can still only fuel one aircraft from the boom at a time.
>
>
> But they have the versatility to fuel multiple hose users; can you name any
> hose refuelers that can do the same for the boom receptacle users?
>
Well, if we want to walk in circles - yeah, the KC10. The point I was
making about the original comment is based about the last three words of
the statement - "... with this mechanism".
How about we ask the (rhetorical) question "how many F15Es can a single
KC10 (with all the bells, whistles, extra dangly bits and go-juice)
simultaneously refuel?"
Then, if we want to get to the point that the original author was trying
to get to, we can ask the question: "How many F18(insert version of
choice here)s can a single KC10 (with ... etc) simultaneously refuel?"
<snip>
>
>
>>Can I ask a question here (well, two, if you count this one)? Could a
>>KC135/KC10 with a boom-mounted drogue still refuel a B52?
>
>
> No, but they *can* (and many do) carry seperate pod mounted hose/drogue
> units that can allow them to feed both types on the same sortie.
>
> If it can't
>
>>then a boomer without MPRS will be waving at probe-only receivers. (The
>>article says that a boom tanker can have a field conversion to handle
>>drogue, but doesn't detail whether this is by fitting a USN buddy store,
>>or by doing something to the boom.)
>
>
> They can add a hose and drogue unit to the end of the boom; a Google image
> search will provide you with some decent photos of the arrangement.
>
... then they've lost the boom-refuel capability for that sortie. That
poor ol' boom operator's doing a lot of waving recently...
(I wasn't sure how it was done, and I didn't have the time to look it
up, but Curt gave a good answer in a different message.)
I probably agree with you. From point of view:
1. If your inventory carries aircraft using different refueling methods
it would be more effective to have tankers that can refuel both.
2. If you need to buy new tankers, and you've got aircraft that are
hose-only and boom-only, it would make sense to buy tankers that could
handle both.
I just can't figure out why the guy who wrote the report got stuck into
the mindset that a new build could be boom, or could be hose, but
couldn't be both.
--
Duncan
Duncan Riddle
>>>As can a lot of boom tankers when using the hose/drogue underwing pods in
>>>combo with their boom-mounted drogue; I belive they can actually handle
>>>up to *three* simultaneous receivers (at least the KC-10's can).
>
>
> While it is physically possible to refuel three aircraft simultaneously, it
> is not allowed as the receiver's wingspans would be too close.
>
>
>>Can I ask a question here (well, two, if you count this one)? Could a
>>KC135/KC10 with a boom-mounted drogue still refuel a B52?
>
>
> No, however, the KC-10 does not use that boom-mounted drogue contraption
> (Boom to Drogue Adaptor, or BDA). It was intended as an interim device but
> has stuck around. The AF attempted to mount a fuselage hose unit on
> KC-135s, just behind the main gear wells. Apparently it did not work so well
> and they stuck with the boom mounted drogue.
>
> The KC-10 has a permanent centerline drogue next to the boom pivot area. So
> a Ten can refuel any fixed wing aircraft on a single mission. The KC-135 can
> do one or the other but not both.
>
Thanks for the explanation. I wanted to see if I was understanding what
the guy was describing properly.
>
>>Option 1 - keep the newer boom tankers, scrap the old ones, buy new hose-
>>tankers because they're cheaper than buying new boom tankers. This leaves
>>you with both boom tankers and hose tankers.
>
>
> Absolutely not; it would be a planner's nightmare having to juggle boom only
> vs. hose only tankers. Equip them with both and the problem goes away.
> They might be cheaper to buy but operations costs would increase because you
> would have to send more tankers to cover all receivers.
>
>
>>Option 2 - scrap the oldest tankers, convert the rest to MPRS (both boom
>>and hose), buy new boom tankers.
>>(For some reason, I'm not spotting the suggestion that new-buy tankers
>>should come with both booms _and_ hoses. Wouldn't it be cheaper to plumb
>>them up from new?)
>
>
> Much cheaper, even if they bought pods later. And don't forget to go the
> KC-10 route and have a fuselage mounted hose/drogue unit along with the
> boom. The wing pods are gravy.
>
> Curt
>
>
>
The wing pods give the opportunity for servicing multiple receivers
simultaneously, which is one of the things the original author was
banging on about. Besides, I'm a brit, and I've grown up with pictures
of Victors & VC10s dangling 3 hoses behind them, so only refuelling one
aircraft at a time seems a little inefficient to me... saying that - if
you look at a Trident tanker, it looks like that can only do one at a
time, but has two hoses (both fuselage mounted).
http://www.raf.mod.uk/downloads/wallpaper/tristar_03_0800.jpg
--
Duncan.
Curt
> simultaneously, which is one of the things the original author was banging
> on about. Besides, I'm a brit, and I've grown up with pictures of Victors
> & VC10s dangling 3 hoses behind them, so only refuelling one aircraft at a
> time seems a little inefficient to me... saying that - if you look at a
> Trident tanker, it looks like that can only do one at a time, but has two
> hoses (both fuselage mounted).
>
> http://www.raf.mod.uk/downloads/wallpaper/tristar_03_0800.jpg
>
The Tristar has two HDUs for redundency. It cannot refuel from both at the
same time. Which, come to think of it, seems to make a statement about hose
and drogue refueling.
Curt
Dave Kearton
Comes in handy if someone snaps the basket off......
Have a vid somewhere of a USN F-4 trapping with the basket still stuck to
his probe.
--
Cheers
Dave Kearton (lucky he doesn't have to explain _that_ to his wife.)
Guy Alcala
Presumably, the statement being that it's possible to have_ redundancy_ when
using hose anddrogue. To date no boom-equipped tanker can say the same, although
Boeing's Blended Wing-Body concept showed two separate booms, one out on each
wing.
Re the TriStar and why it has two centerline drogues. Quoting now from a March
1991 article in Air International titled "Tristar: The Answer to an Operational
Requirement":
"The one problem area not resolved was the fitting of refueling equipment to the
wings. Indeed, it is a problem that remains today. Lockheed confirmed, at the
time of purchase of the aircraft, that the wing structure was strong enough to
carry the Flight Refueling Ltd Mk.32 pods and associated internal equipment, but
a detailed design study was not undertaken at that stage. Subsequently it
emerged that there were significant problemsas the wings incorporated active
ailerons, which would probably have to be divided as part of the work to fit pod
mounting pylons.
"As this threatened the timescale of the whole program, it was decided to press
on with the centre-line refueling station modification, incorporating two AAR
HDUs for redundancy, and tackle the wing modification later."
The justification for this was that the Tristars were being bought primarily to
provide tanking for C-130s flying to and from Port Stanley airfield in the
Falklands, so refueling large numbers of a/c in a short period of time wasn't an
issue but redundancy was. When the British government decided to build RAF Mt.
Pleasant airfield, which was heavy transport capable (indeed, it was designed
around the requirements of the Tristar), the rationale for the Tristar changed
to it making direct pax and cargo flights Ascension - Mt. Pleasant, rather than
tanking C-130s on that run, and so the early development of wing pods to refuel
two fighters at a time became more important when the a/c operated as a tanker.
The quoted statement in the article apparently caused a bit of a ruckus (since
it implied a serious screw-up on the part of MoD and/or the contractor with the
public's money), resulting in the reply in the "Talkback" (letters) section of
the magazine in the following issue:
"Sir -- We were delighted to read Wg Cdr Bob Prothero's history of the RAF
Tristar development in the March issue as our company was deeply involved in the
early days and how the aircraft specification was gradually developed.
"As he says, the one area not resolved then was the fitting of wing refueling
pods, which would give considerable benefit for refueling pairs of tactical
aircraft. Although current Tristar tankers can deliver fuel at very high rates
through their centreline hose, smaller receiver aircraft are limited in the rate
they can accept fuel and thus have to remain connected to the tanker for a
considerable period, so delaying subsequent receivers their ability to refuel.
"We are not sure where Bob Prothero heard that there might be technical problems
with fitting the wing refueling pods. He agrees that there was no official
mention of concern about active ailerons, and certainly not the need to divide
the ailerons to accommodate the wing pylon. Those involved in the programme at
Marshall's are convinced that there is no major technical risk to the project.
Our initial studies into both aerodynamic and structural aspects confirm this
and show the programme to be straightforward.
"We see the capability of the Tristar to be greatly enhanced once wing pods are
fitted and have every intention in the future of providing for the Royal Air
Force, and probably other air forces, Tristar tankers able to refuel fast jets
two at a time.
"Max Bacon
Marshall of Cambridge (Engineering) LTD
Cambridge"
Everything's fine, nothing to worry about, trust us, we know what we're
doing;-) More than 15 years later the Tristar still doesn't have wing pods.
Fortunately for the RAF they've got the VC-10 tankers, which are three-point
(some of the initial conversions were two-point, but I think they've all been
brought up to three-point since).
Guy
Kevin Brooks
The KC-10 is a boomer. And as yet I have heard nothing that indicates it is
capable of handling multiple boom receivers...it can, using the pods, handle
multiple hose users. I asked if you knew of any hose refuelers that could
feed multiple boom receivers (we both know that they can't feed *any* boom
receivers).
The point I was
> making about the original comment is based about the last three words of
> the statement - "... with this mechanism".
But he ignored the fact that they have the versatility to fuel multiple
aircraft using the same hose/drogue system that he apparently thinks is a
better option, while retaining their ability to handle the boom receivers as
well.
>
> How about we ask the (rhetorical) question "how many F15Es can a single
> KC10 (with all the bells, whistles, extra dangly bits and go-juice)
> simultaneously refuel?"
It does not really matter. It can fuel enough to satisfy the mission
requirement.
>
> Then, if we want to get to the point that the original author was trying
> to get to, we can ask the question: "How many F18(insert version of choice
> here)s can a single KC10 (with ... etc) simultaneously refuel?"
You might be better to ask, "How many F-15E's can an RAF Tristar refuel?"
The answer being, of course, zero. OTOH, the KC-10 can fuel one F-15E at a
time, and two F/A-18's at a time (three has been demonstrated, but as
another poster noted that is likely not acceptable for normal operations).
>
>
> <snip>
>>
>>
>>>Can I ask a question here (well, two, if you count this one)? Could a
>>>KC135/KC10 with a boom-mounted drogue still refuel a B52?
>>
>>
>> No, but they *can* (and many do) carry seperate pod mounted hose/drogue
>> units that can allow them to feed both types on the same sortie.
Correct myself. The 135 can't, the KC-10 can.
>>
>> If it can't
>>
>>>then a boomer without MPRS will be waving at probe-only receivers. (The
>>>article says that a boom tanker can have a field conversion to handle
>>>drogue, but doesn't detail whether this is by fitting a USN buddy store,
>>>or by doing something to the boom.)
>>
>>
>> They can add a hose and drogue unit to the end of the boom; a Google
>> image search will provide you with some decent photos of the arrangement.
>>
>
> ... then they've lost the boom-refuel capability for that sortie. That
> poor ol' boom operator's doing a lot of waving recently...
Only the 135; the KC-10 retains full boom capability. And as you obviously
know, the 135's can carry the pods that allow them to handle both types of
receivers on the same mission--until somebody comes up with a truly amazing
pod for hosers that deploys an "insta-boom", this means that the king of
versatility is going to be the boomers. And versatility is probably *the*
watchword for modern military procurement... single-role is a good way to
end up on the chopping block, not to mention that it complicates the theater
commander's job.
Typical CRS/GAO/CBO/etc. (name any of the homes for those who predominantly
have only an academic background for military matters) situation; take an
academic who has no real experience or even a decent background knowledge
base, stir in a bit of bias (often conferred by who requested the study),
toss in a pinch of failing to do his research, add a dash of the "I know
better than the uniformed cretins" mentality, and *presto*, there you have
it...
Brooks
>
> --
> Duncan
>
Kevin Brooks
"Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
news:44A5F436...@junkpostoffice.pacbell.net...
Uhmmm...how often does the boom fail during a mission? From what I gather,
the boomers really don't *need* that kind of redundancy, while the hosers
do. Which would make it a non-issue for the boomers.
Brooks
<snip>
Guy Alcala
> Kevin Brooks wrote:
> > "Duncan Riddle"
> > <duncan.getrido...@btinternet.andthisbitaswell.com> wrote in
> > message news:99ednZ5g1v2NUD7Z...@bt.com...
> >
> <snip>
> >>
> >>The statement doesn't say that NATO etc exclusively use hose-and-drogue.
> >
> >
> > It makes that inference, as it does not mention anything about the fact that
> > some NATO countries do indeed use booms. In fact, if you compare the actual
> > real tanker inventories of the European NATO nations (only a handful have
> > such systems of any tupe), you will find almost as many boom operators as
> > hose-and-drogue users. I count four users equipped with tankers that have
> > booms (though I don't think the French use their boomers for anything but
> > hose/drogue). The hose and drogue users number two or three (or four if you
> > include the French), not counting those countries that have resorted to the
> > C-130-as-cheap-tanker-alternative approach. Hardly the situation the writer
> > described.
> >
>
> Ok. Inference is in the eye of the beholder. Could be that the guy just
> went "Hmmm... NATO, let's see that's the limeys and the krauts and some
> other guys. The RAF uses hoses, who cares what the Germans use and the
> others don't even have airforces..." ;-)
Offhand, I come up with the following for NATO nations (other than the US) with
tankers:
H & D: Canada, France, Germany, Spain, UK, Italy.
B & R: Italy (soon), Netherlands.
Who am I missing? There's probably some KC-130 operators I've forgotten, and ISTR
Turkey's hoping to get some used KC-135s from us for their F-16s, although IIRR
their F-4s have been modded with Israeli probes. Or maybe I'm thinking of the
Spanish RF-4s. Not that you have to use a boom to refuel F-16s and similar
receptacle-equipped a/c. Even if you don't give them integral probes, the
Israelis demonstrated buddy refueling of F-16s by F-15s a few years back, using a
buddy store and Sargent-Fletcher's drop-tank mounted extendible probe:
http://www.sargentfletcher.com/ars_charact.htm#ARTS Table
Scroll down to "Aerial Refueling tank/System"
This harks back to the first AAR fighter missions in the Korean War, which used
non-retractable probes attached to drop tanks.
Guy
Guy Alcala
I've certainly read accounts of booms being broken while refueling, and of
course pumps, plumbing and electrical systems can always fail. Curt stated
"The MTBF of the boom is many times that of a drogue. Further, if a boom has a
problem it
can still be stowed and brought back for repair. OTOH, a hose malfunction
frequently means
jettisoning the hose."
So while booms may be more reliable than hose/drogues, they aren't more reliable
than two or more separate hose/drogues on the same a/c, so you're not SOL if
that end of the system breaks. Of course, if the probe breaks off or the end of
the boom breaks off in the receptacle the receiver's still screwed, but at least
they had another chance.
Guy
>
>
> Brooks
>
> <snip>
Guy Alcala
> "Duncan Riddle"
> <duncan.getrido...@btinternet.andthisbitaswell.com> wrote in
<snip>
> The point I was
> > making about the original comment is based about the last three words of
> > the statement - "... with this mechanism".
>
> But he ignored the fact that they have the versatility to fuel multiple
> aircraft using the same hose/drogue system that he apparently thinks is a
> better option, while retaining their ability to handle the boom receivers as
> well.
No, he didn't, you didn't read the entire article.
> > How about we ask the (rhetorical) question "how many F15Es can a single
> > KC10 (with all the bells, whistles, extra dangly bits and go-juice)
> > simultaneously refuel?"
>
> It does not really matter. It can fuel enough to satisfy the mission
> requirement.
Assuming that more than one isn't on the point of flameout due to fuel
starvation. A/C have been lost for that reason. And there can also be problems
with flights needing to cycle on and off the boom because of the wait time.
> > Then, if we want to get to the point that the original author was trying
> > to get to, we can ask the question: "How many F18(insert version of choice
> > here)s can a single KC10 (with ... etc) simultaneously refuel?"
>
> You might be better to ask, "How many F-15E's can an RAF Tristar refuel?"
> The answer being, of course, zero.
As the F-15Es are currently equipped. See link in other post to Sargent Fletcher
probe tank, and there's likely no technical reason why you couldn't mount at
least a fixed probe on the a/c itself.
> OTOH, the KC-10 can fuel one F-15E at a
> time, and two F/A-18's at a time (three has been demonstrated, but as
> another poster noted that is likely not acceptable for normal operations).
And having the choice is definitely the best option for the USAF, and the report
never disputes that.
> >>>Can I ask a question here (well, two, if you count this one)? Could a
> >>>KC135/KC10 with a boom-mounted drogue still refuel a B52?
> >>
> >>
> >> No, but they *can* (and many do) carry seperate pod mounted hose/drogue
> >> units that can allow them to feed both types on the same sortie.
>
> Correct myself. The 135 can't, the KC-10 can.
Yeah, and the boom-mounted drogue on the KC-135 is called a variety of names by
USN/USMC pilots, few of them printable. "Bastard afterthought" being one of the
more gentile. ISTR it being referred to as the "Iron Maiden", and have read
accusations (in Sherman Baldwin's "Ironclaw" IIRR) that some senior pilots of
his and other squadrons on the Midway during DS would find a reason to down
their a/c if they knew they would be refueling from one, especially at night.
Be that as it may, I've never seen a single pilot with experience of a standard
hose/drogue who had a good thing to say about the KC-135 boom's add-on drogue.
> >> If it can't
> >>
> >>>then a boomer without MPRS will be waving at probe-only receivers. (The
> >>>article says that a boom tanker can have a field conversion to handle
> >>>drogue, but doesn't detail whether this is by fitting a USN buddy store,
> >>>or by doing something to the boom.)
> >>
> >>
> >> They can add a hose and drogue unit to the end of the boom; a Google
> >> image search will provide you with some decent photos of the arrangement.
> >>
> >
> > ... then they've lost the boom-refuel capability for that sortie. That
> > poor ol' boom operator's doing a lot of waving recently...
>
> Only the 135; the KC-10 retains full boom capability. And as you obviously
> know, the 135's can carry the pods that allow them to handle both types of
> receivers on the same mission
IIRR, only 20 or maybe it was 40 (we bought either 40 pods or 40 mod kits, I
forget which) KC-135Rs which were so modified.
> >>>>And what of the requirement (which won't go away) to refuel the larger
> >>>>aircraft (i.e., B-1B, B-52, B-2, C-5, C-17, E-8, RC-135, etc.) that can
> >>>>indeed still use the full greater capacity of the boom unit?
> >>>
> >>>That's addressed (reformatted for clarity):
> >>><quote>
> >>>One option would be to replace the oldest KC-135s with new aircraft
> >>>equipped with two refueling hoses. Structural modifications to commercial
> >>>aircraft to accommodate a flying boom are more significant than the
> >>>modifications for hose-and-drogue mechanisms. The boom itself also costs
> >>>more than the hose-and-drogue and is more complex. Thus, these new
> >>>aircraft would likely be less costly than new, boom-equipped tankers.
> >>>Newer KC-135s and KC-10s with booms would need to be retained to refuel
> >>>large aircraft.
> >>
> >>
> >> Wonderful plan--you have to have the exact right kind of refuelers
> >> available in area X to handle receiver Y? Doesn't that sound a bit
> >> complicated?
Certainly has been for the USAF and the KC-135 with add-on drogue, going back to
Vietnam. IIRC, drogue-equipped KC-135s were referred to as "Papa" tankers to
distinguish them from the usual variety. This was apparently done for phonetic
reasons (Papa = probe), but given the fighter pilot mentality I've always
thought that calling them "mama" tankers would be more appropriate to the role,
and less likely to cause confusion;-)
<snip>
> > I probably agree with you. From point of view:
> >
> > 1. If your inventory carries aircraft using different refueling methods it
> > would be more effective to have tankers that can refuel both.
> >
> > 2. If you need to buy new tankers, and you've got aircraft that are
> > hose-only and boom-only, it would make sense to buy tankers that could
> > handle both.
> >
> > I just can't figure out why the guy who wrote the report got stuck into
> > the mindset that a new build could be boom, or could be hose, but couldn't
> > be both.
>
> Typical CRS/GAO/CBO/etc. (name any of the homes for those who predominantly
> have only an academic background for military matters) situation; take an
> academic who has no real experience or even a decent background knowledge
> base, stir in a bit of bias (often conferred by who requested the study),
> toss in a pinch of failing to do his research, add a dash of the "I know
> better than the uniformed cretins" mentality, and *presto*, there you have
> it...
Nowhere in the report does he say that you can't have both, or that that
wouldn't be the ideal option. The question is what can you afford and what do
you really need, versus what would just be nice to have. I'd summarise the
report as follows:
1. Only the big boys really need a boom (although the Brits would dispute that,
given that maximum hose flow rates are far higher now than was true in the
'50s).
2. Fighter flights benefit from having multiple refueling points on the same
a/c, and can't make use of the maximum flow rate from a boom in any case.
Remember that one of the USAF's justifications for the 767 instead of a larger
tanker was that the driver in tactical situations was the number of booms in the
air, not the individual offload per tanker. So, it made sense to use a smaller
a/c that wouldn't take up as much ramp space and thus, more could be deployed to
the limited number of airfields in theater, given the limit on only one boom per
a/c. Multi-point refueling on the same a/c gives an even larger operational
benefit.
3. The vast majority of other countries that have AAR capability, either as
tankers or receivers, use probe and drogue, as do every other country's a/c
manufacturers. P&D is undoubtedly cheaper, simpler and more versatile, allowing
rapid installation on a/c that weren't originally designed for it, as well as
the creation of instant tankers using buddy stores.
4. The installed base of USAF a/c, as well as many of our likely allies who use
the same a/c, is B&R, so we will need that capability for some time to come.
5. However, for the next generation of a/c (F-35 etc.), we aren't locked into
the same ratio of B&R/P&D as we now have, provided we make the decision to start
changing the mix soon. And we can modify many if not all of our current tactical
a/c (the RAAF F-111s probably being the sole exception, owing to the "escape
capsule") we now have to use P&D, just as the Israelis modified all their F-4s.
We pay a small drag penalty but gain immensely in interoperability and
versatility.
6. As to operating a mixed tanker fleet, we have always done so. During the
1950s and early 1960s TAC used P&D and SAC used B&R. The Navy and Marines as
well as AFSOC continue to use P&D,so this really isn't a big issue. Any
transition will take years in any case. If we can maintain a small, specialized
fleet of HC-130s (or is it MC-130s, I can never remember) to refuel helos, we
can certainly maintain a somewhat larger specialized boom-equipped fleet to
handle the big boys, whose arrival and departure tends to be much more
predictable than is the case with tactical a/c.
Guy
mike Williamson
>
> Each receiver has an optimum speed but it can adjusted for conditions. It
> can vary a lot based on the receiver's weight. 280-300 KIAS for fighters is
> a good ballpark figure. 275 for heavies. A-10s and C-130s were in the lower
> 200s, sometimes with the tanker's flaps and/or slats deployed. The F-18s do
> not appear to have flaps deployed; there would be no reason for flaps. The
> Ten can easily fly at any receiver's AR speed, with a clean wing, at max
> weight. The tanker usually has to slow for refueling. The KC-10 refuelled
> at 290 KIAS, although we might accelerate up to 310 knots when heavy.
>
> Curt
Not sure on the A-10s, but refuelling airspeed for C-130s is 200 KIAS.
In many cases we'd like to go slower, but if the tanker is heavy we are
stuck at 200.
Mike W
EC-130H
Guy Alcala
Found the following old post squirreled away in my "tanker refueling speeds"
folder:
-------- Original Message --------
Subject: Re: Tanker Aircraft Stall Speeds
Date: 21 Apr 2001 05:32:58 GMT
From: goo...@aol.comXXZZ (MWG)
Organization: AOL http://www.aol.com
Newsgroups: rec.aviation.military
References: <9apqrt$gp9$1...@slb6.atl.mindspring.net>
>Hi all. Just wondering if anyone knows the stall speeds
of the KC-10,
>KC-135, and KC-130? I've been thinking about this ever
since seeing pics of
>the A-10 refueling from the KC-10 and the KC-135, and
H-53s/H-60s refueling
>from K/C-130s. Thanks.
>
The 135 refuels C130's and A-10s at 200 KIAS. The max tanker gross weight for
both at beginning A/R is is 250,000 lbs. Initial buffet speed at 10,000' and 250K
gross weight is 178 IAS flaps up (160KIAS flaps 20). A full stall occurs at 15-20
knots below initial buffet speed (10 knots
below with flaps). This would obviously increase when in a turn. So it really is
pretty far above the
stall speed. This is really irrelevant since the boom operator has a difficult
time "flying" the boom at speeds below 190KIAS. You just don't refuel below this,
at least not for very long. Besides that, the book says don't do it!
AC-130s, since they are real heavy, usually ask to refuel at 190KIAS if possible
and often ask to toboggan (200-400' per minute while in contact). At 250K Gross
weight the flaps 30 (and I have used 30 flaps when doing a 130), the approach
speed is 194 knots and that is what I usually
fly until I am lighter.
MG Tanker IP
NJE
Guy Alcala <g_al...@junkpostoffice.pacbell.net> wrote:
<snip>
>
> 3. The vast majority of other countries that have AAR capability, either as
> tankers or receivers, use probe and drogue, as do every other country's a/c
> manufacturers. P&D is undoubtedly cheaper, simpler and more versatile,
> allowing
> rapid installation on a/c that weren't originally designed for it, as well as
> the creation of instant tankers using buddy stores.
>
This leads me to ask a question:
As best I understand it, all the probe and drogue system used by western
forces are derived from the work of Flight Refuelling Limited in Britain
so they are inter-operable. Are the systems used by the former eastern
bloc (what ever the ex-USSR is called now) air forces compatible with
the western systems? I assume the concept of both systems is the same
but are the connections the same size?
--
NJE
Kevin Brooks
> Kevin Brooks wrote:
>
>> "Duncan Riddle"
>> <duncan.getrido...@btinternet.andthisbitaswell.com> wrote in
>
> <snip>
>
>> The point I was
>> > making about the original comment is based about the last three words
>> > of
>> > the statement - "... with this mechanism".
>>
>> But he ignored the fact that they have the versatility to fuel multiple
>> aircraft using the same hose/drogue system that he apparently thinks is a
>> better option, while retaining their ability to handle the boom receivers
>> as
>> well.
>
> No, he didn't, you didn't read the entire article.
He did in the early part that I read, and then later he came up with that
astounding "mixed force" design proposal that fell flat as a pancake.
>
>> > How about we ask the (rhetorical) question "how many F15Es can a single
>> > KC10 (with all the bells, whistles, extra dangly bits and go-juice)
>> > simultaneously refuel?"
>>
>> It does not really matter. It can fuel enough to satisfy the mission
>> requirement.
>
> Assuming that more than one isn't on the point of flameout due to fuel
> starvation. A/C have been lost for that reason. And there can also be
> problems
> with flights needing to cycle on and off the boom because of the wait
> time.
Guy, I think you have some sort of Pavlovian thing going when it comes to
USAF tanker programs. The USAF has been very happy with the boom system--I
would think that might count for something? And is your flame-out ready
fighter going to be well served when he can't hit the basket, or the
basket/hose fails (as really happens more than boom failures)?
>
>> > Then, if we want to get to the point that the original author was
>> > trying
>> > to get to, we can ask the question: "How many F18(insert version of
>> > choice
>> > here)s can a single KC10 (with ... etc) simultaneously refuel?"
>>
>> You might be better to ask, "How many F-15E's can an RAF Tristar refuel?"
>> The answer being, of course, zero.
>
> As the F-15Es are currently equipped. See link in other post to Sargent
> Fletcher
> probe tank, and there's likely no technical reason why you couldn't mount
> at
> least a fixed probe on the a/c itself.
Wow. So now we go to all of this troble, and expense, to remedy a
problem...that is not really a problem. Sorry. New tankers with booms and
the ability to carry pods for hosers is the better solution.
>
>> OTOH, the KC-10 can fuel one F-15E at a
>> time, and two F/A-18's at a time (three has been demonstrated, but as
>> another poster noted that is likely not acceptable for normal
>> operations).
>
> And having the choice is definitely the best option for the USAF, and the
> report
> never disputes that.
Gee, that whole first part made it sound like booms were just a real waste,
and the USAF is the only organization foolish enough to pursue them. Then he
followed with his "buy aircraft with hoses, and keep some of the old KC's
around to handle the boomers" junk.
We are talking future options here, Guy.
One USAF type who actually has tanker experience has already taken the
notion that only the big boys can use the capacity to task, IIRC.
>
> 2. Fighter flights benefit from having multiple refueling points on the
> same
> a/c, and can't make use of the maximum flow rate from a boom in any case.
See above.
Too late now, gotta run...
Brooks
Kevin Brooks
I doubt Spain has anything bigger than a C-130 doing this?
>
> B & R: Italy (soon), Netherlands.
>
> Who am I missing?
Turkey uses booms. France is a KC-135 operator, but they use it woth the
drogue on the boom IIRC. BTW, booms are also in service with Singapore and
now Japan is getting them, too; not sure if the Aussies went the boom route
with their new AI tankers or not.
There's probably some KC-130 operators I've forgotten, and ISTR
> Turkey's hoping to get some used KC-135s from us for their F-16s,
Aleady got them I think.
Brooks
Kevin Brooks
Uhmmm..if they are "many" time more reliable, they certainly can be.
Brooks
Guy Alcala
Good question. India has both Western and Russian a/c with probes in her inventory,
and she's bought IL-78 tankers. The only info I have are the photos here, which
indicate that they are compatible:
http://www.bharat-rakshak.com/IAF/Images/Current/AAR.html
Of course, it could be that India special-ordered probes using one or the other
system and fit them to whichever a/c would normally have the other type.
Guy
Guy Alcala
Good question. India has both Western and Russian a/c with probes in her inventory,
Guy Alcala
Good question. India has both Western and Russian a/c with probes in her inventory,
and she's bought IL-78 tankers. The only info I have are the photos here, which
indicate that they are compatible:
http://www.bharat-rakshak.com/IAF/Images/Current/AAR.html
Of course, it could be that India special-ordered probes using one or the other
system, and fit them to whichever a/c would normally have the other type to achieve
commonality.
Guy
Guy Alcala
> "Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
> news:44A62028...@junkpostoffice.pacbell.net...
<snip>
> >> Uhmmm...how often does the boom fail during a mission? From what I
> >> gather,
> >> the boomers really don't *need* that kind of redundancy, while the hosers
> >> do. Which would make it a non-issue for the boomers.
> >
> > I've certainly read accounts of booms being broken while refueling, and of
> > course pumps, plumbing and electrical systems can always fail. Curt
> > stated
> >
> > "The MTBF of the boom is many times that of a drogue. Further, if a boom
> > has a
> > problem it
> > can still be stowed and brought back for repair. OTOH, a hose malfunction
> > frequently means
> > jettisoning the hose."
> >
> > So while booms may be more reliable than hose/drogues, they aren't more
> > reliable
> > than two or more separate hose/drogues on the same a/c,
>
> Uhmmm..if they are "many" time more reliable, they certainly can be.
True, poor wording on my part. While they _can_ be, AFAIK no one has claimed
that the MTBA(borts) of a single boom is better than the MTBA of _two_ HDUs on a
single a/c. If anyone has data that shows otherwise, I will happily admit my
error.
Guy
Guy Alcala
> "Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
> news:44A63025...@junkpostoffice.pacbell.net...
> > Kevin Brooks wrote:
> >
> >> "Duncan Riddle"
> >> <duncan.getrido...@btinternet.andthisbitaswell.com> wrote in
> >
> > <snip>
> >
> >> The point I was
> >> > making about the original comment is based about the last three words
> >> > of
> >> > the statement - "... with this mechanism".
> >>
> >> But he ignored the fact that they have the versatility to fuel multiple
> >> aircraft using the same hose/drogue system that he apparently thinks is a
> >> better option, while retaining their ability to handle the boom receivers
> >> as
> >> well.
> >
> > No, he didn't, you didn't read the entire article.
>
> He did in the early part that I read, and then later he came up with that
> astounding "mixed force" design proposal that fell flat as a pancake.
As I pointed out, we've always had a mixed tanker force, across (and usually
within) services.
> >> > How about we ask the (rhetorical) question "how many F15Es can a single
> >> > KC10 (with all the bells, whistles, extra dangly bits and go-juice)
> >> > simultaneously refuel?"
> >>
> >> It does not really matter. It can fuel enough to satisfy the mission
> >> requirement.
> >
> > Assuming that more than one isn't on the point of flameout due to fuel
> > starvation. A/C have been lost for that reason. And there can also be
> > problems
> > with flights needing to cycle on and off the boom because of the wait
> > time.
>
> Guy, I think you have some sort of Pavlovian thing going when it comes to
> USAF tanker programs.
How so?
> The USAF has been very happy with the boom system--I
> would think that might count for something?
Certainly, it served SAC and MAC, where it was really needed, excellently for
decades, and worked well for TAC once they got rid of all their probe-only
equipped a/c, the F-100C/D/F, F-104C, F-105B, F-5C, A-37 and EB-66 to name six
that come to mind.
> And is your flame-out ready
> fighter going to be well served when he can't hit the basket,
Sometimes it just isn't your day.
> or the
> basket/hose fails (as really happens more than boom failures)?
Which is why it's a good thing to have another one handy.
> >> > Then, if we want to get to the point that the original author was
> >> > trying
> >> > to get to, we can ask the question: "How many F18(insert version of
> >> > choice
> >> > here)s can a single KC10 (with ... etc) simultaneously refuel?"
> >>
> >> You might be better to ask, "How many F-15E's can an RAF Tristar refuel?"
> >> The answer being, of course, zero.
> >
> > As the F-15Es are currently equipped. See link in other post to Sargent
> > Fletcher
> > probe tank, and there's likely no technical reason why you couldn't mount
> > at
> > least a fixed probe on the a/c itself.
>
> Wow. So now we go to all of this troble, and expense, to remedy a
> problem...that is not really a problem.
Of course it's a problem, of interoperability. Note that I'm not recommending
that we do such a retrofit, as the cheapest solution is to let natural attrition
work by ordering new tactical a/c with probes while keeping enough boom-equipped
tankers around for the ever-dwindling number of receptacle-equipped a/c. Which
is more or less what the USAF did going the other way in the 1960s, as TAC
probe-only a/c were replaced by those with receptacles. Once the last TAC KB-50
was retired we had to equip a percentage of the KC-135 fleet with add-on
drogues, until the last probe-only USAF a/c were retired. I imagine that came
about when the last A-37 was sold or went to the boneyard. Of course, by the
time that happened we were increasingly working with USN/USMC and foreign air
forces equipped with probes, so SAC was unable to get rid of the KC-135 drogues,
and (as ACC) had to buy some wing pods.
> Sorry. New tankers with booms and
> the ability to carry pods for hosers is the better solution.
That is _a_ solution, certainly the most versatile in terms of interoperability,
albeit possibly the most expensive one. Another solution, which might be even
more expensive, would be to fit all receiver a/c with both systems, ala the
F-101/F-105 and Israeli-modified F-4s. And then there's the solution mooted in
the paper, which is almost certainly the quickest and cheapest of the three.
> >> OTOH, the KC-10 can fuel one F-15E at a
> >> time, and two F/A-18's at a time (three has been demonstrated, but as
> >> another poster noted that is likely not acceptable for normal
> >> operations).
> >
> > And having the choice is definitely the best option for the USAF, and the
> > report
> > never disputes that.
>
> Gee, that whole first part made it sound like booms were just a real waste,
> and the USAF is the only organization foolish enough to pursue them.
It didn't sound like that to me (of course, I read the whole report), and it
certainly never stated or intimated that the USAF was foolish to pursue them. It
laid out their advantages and disadvantages vs. probe and drogue, and stated
that booms definitely had the advantage for large a/c. But we no longer operate
1,500+ B-47s or even 500+ B-52s in addition to the other odds and sods that
really benefit from B&R. We've got about 100 heavy bombers and will have 180 or
so C-17s plus mumblety-odd C-5s and 58 or so KC-10s, plus the odd E-3/E-4/E-6
etc.
> Then he
> followed with his "buy aircraft with hoses, and keep some of the old KC's
> around to handle the boomers" junk.
Which is one possible (and reasonable) solution among several, and IMO one that
the USAF and DoD should consider. After an objective analysis they may
determine that it's not the most cost-effective option, and I won't argue with
that conclusion if I believe that it was honestly arrived at. But dismissing it
out of hand without even running the numbers, when interoperability is
increasingly important and large-scale tanker and fighter re-capitalization is
going to start soon, would be foolish IMO.
<snip>
> >> > ... then they've lost the boom-refuel capability for that sortie. That
> >> > poor ol' boom operator's doing a lot of waving recently...
> >>
> >> Only the 135; the KC-10 retains full boom capability. And as you
> >> obviously
> >> know, the 135's can carry the pods that allow them to handle both types
> >> of
> >> receivers on the same mission
> >
> > IIRR, only 20 or maybe it was 40 (we bought either 40 pods or 40 mod kits,
> > I
> > forget which) KC-135Rs which were so modified.
>
> We are talking future options here, Guy.
Yes, and please keep that in mind when considering if we need all our tankers to
be boom-equipped.
<snip>
IIRR he didn't say that fighters were able to use the maximum boom transfer rate
(ca. 9,000lb./min. for the KC-10 IIRC, about 6,500 lb./min. for the KC-135),
only that a fighter was still able to refuel at higher rates with a boom than a
drogue.
> > 2. Fighter flights benefit from having multiple refueling points on the
> > same
> > a/c, and can't make use of the maximum flow rate from a boom in any case.
>
> See above.
Ditto.
> Too late now, gotta run...
Gotta sleep;-)
Guy
WaltBJ
nothing about refueling probe and drogue. I do know from other people's
experiences it is more difficult than using the boom. I'm not thrilled
at the idea of losing knots of airspeed and burning more fuel to shove
an external probe around the sky. I also suspect that thing would
create noise in the cockpit when on the deck going fast. And just how
is one supposed to incorporate a retractable probe into a fighter not
designed from the first to have one?
I conclude that a flight of four will be off the tanker faster
using the boom. IFR on the boom is simple; it's just a matter of
recognizing where you're supposed to be and staying there. The lights
then become almost nugatory. As for offload rates, we once tried 8 F4s
on one KC135. That was a lesson in frustration since as flight lead I
was back down to where I started before #8 got off the boom. Not that
the tank was giving us all that much. 7th AF planning was remiss that
mission . . .
As for speeds - refueling an F4 with a full load of ordnance
aboard at 25000 generally required going to min AB on one engine when
half-way through the offload while adjusting the other one somewhat
below full military to stay in position. Engaging an AB while hooked up
was always 'interesting'. Another feature of refueling off the
centerline boom is that the tanker gives a beautiful reference when
refueling in night weather, not that uncommon back then on Cherry
anchor. Getting 'towed' through an embedded thunderstorm is an
experience in frenetic formation flying, too.
So - screw the academic approach; wing podded drogues and a
centerline boom is the way to go. Always thought two of the principles
of warfare were flexibility and economy of resources. As for refueling
3 at once off a KC 10 - just what were the clearances in feet, anyway?
I wonder if the author knew anything about wingtip clearance in flying
wing weather. Most likely less than the width of his desk, not to
mention his posterior. (G) 3x104s would fit very nicely, Guy! So would
AV8s and A4s (if we still had any.)
Anytime some academic writes about flying and does not cite
references and authorities he 's contacted - suspect an axe is being
ground. tTis one seems to have been quite thoroughly ground - and the
books cooked, besides.
Walt BJ
Kevin Brooks
"WaltBJ" <walt...@mindspring.com> wrote in message
news:1151873501....@h44g2000cwa.googlegroups.com...
Agreed.
As for refueling
> 3 at once off a KC 10 - just what were the clearances in feet, anyway?
> I wonder if the author knew anything about wingtip clearance in flying
> wing weather.
The author of that bit (me) was merely pointing out that the KC-10 had
actually demonstrated once-upon-a-time that it could actually do it, with
F/A-18's being the receivers--unless you figure the photo was faked?
Most likely less than the width of his desk, not to
> mention his posterior.
Why are you interested in my posterior?
Brooks
Kevin Brooks
A bit of a stretch to make that claim. The USAF is exclusively boom oriented
(and has been for many years) with the exception of its helo fleet, and I
doubt anyone is arguing that the next generation tanker should be optimized
to handle helo refueling, which will likely remain the domain of the
specialist MC-130 variants. You don't really envision KC-135/10/767's
refueling helos, do you?
>
>> >> > How about we ask the (rhetorical) question "how many F15Es can a
>> >> > single
>> >> > KC10 (with all the bells, whistles, extra dangly bits and go-juice)
>> >> > simultaneously refuel?"
>> >>
>> >> It does not really matter. It can fuel enough to satisfy the mission
>> >> requirement.
>> >
>> > Assuming that more than one isn't on the point of flameout due to fuel
>> > starvation. A/C have been lost for that reason. And there can also be
>> > problems
>> > with flights needing to cycle on and off the boom because of the wait
>> > time.
>>
>> Guy, I think you have some sort of Pavlovian thing going when it comes to
>> USAF tanker programs.
>
> How so?
You get your fangs out whenever the USAF's desires regarding tanking are
made known.
>
>> The USAF has been very happy with the boom system--I
>> would think that might count for something?
>
> Certainly, it served SAC and MAC, where it was really needed, excellently
> for
> decades, and worked well for TAC once they got rid of all their probe-only
> equipped a/c, the F-100C/D/F, F-104C, F-105B, F-5C, A-37 and EB-66 to name
> six
> that come to mind.
The F-5C? What was that? The last USAF tactical fighter using the probe was
retired sometime in the eighties, IIRC, and that is only if you count the
OA-37's as being "tactical fighters", which is a bit of a stretch.
>
>> And is your flame-out ready
>> fighter going to be well served when he can't hit the basket,
>
> Sometimes it just isn't your day.
But you thought it so important when the subject was the boom receiver
aircraft...
>
>> or the
>> basket/hose fails (as really happens more than boom failures)?
>
> Which is why it's a good thing to have another one handy.
In the event the MTBF for the hoses is multiple times that of the boom, you
still run a decent chance of being completely NMC.
>
>> >> > Then, if we want to get to the point that the original author was
>> >> > trying
>> >> > to get to, we can ask the question: "How many F18(insert version of
>> >> > choice
>> >> > here)s can a single KC10 (with ... etc) simultaneously refuel?"
>> >>
>> >> You might be better to ask, "How many F-15E's can an RAF Tristar
>> >> refuel?"
>> >> The answer being, of course, zero.
>> >
>> > As the F-15Es are currently equipped. See link in other post to Sargent
>> > Fletcher
>> > probe tank, and there's likely no technical reason why you couldn't
>> > mount
>> > at
>> > least a fixed probe on the a/c itself.
>>
>> Wow. So now we go to all of this troble, and expense, to remedy a
>> problem...that is not really a problem.
>
> Of course it's a problem, of interoperability.
No, it is not. As we have been saying, the answer is to provide the wing
pods to the boomers, which allows them to service both. Nobody with half a
brain expects the USN refuelers need be able to refuel USAF assets, so the
interoperability argument becomes meaningless.
Note that I'm not recommending
> that we do such a retrofit, as the cheapest solution is to let natural
> attrition
> work by ordering new tactical a/c with probes while keeping enough
> boom-equipped
> tankers around for the ever-dwindling number of receptacle-equipped a/c.
Bal;derdash--you are back to fielding a mixed future force with part of it
unable to handle a big chunk of the assets. If you won't take it from me,
then listen to Curt's opinion as to how much sense that makes.
Back to the two-tier force that has already been discounted as wasteful?
>
>> >> OTOH, the KC-10 can fuel one F-15E at a
>> >> time, and two F/A-18's at a time (three has been demonstrated, but as
>> >> another poster noted that is likely not acceptable for normal
>> >> operations).
>> >
>> > And having the choice is definitely the best option for the USAF, and
>> > the
>> > report
>> > never disputes that.
>>
>> Gee, that whole first part made it sound like booms were just a real
>> waste,
>> and the USAF is the only organization foolish enough to pursue them.
>
> It didn't sound like that to me (of course, I read the whole report),
You need to go back and read the first part where he claims that only the
USAF operated boom receiver aircraft, implied that NATO was all probe based,
and drew some questionable conclusions about the value of the boom to
fighter aircraft.
and it
> certainly never stated or intimated that the USAF was foolish to pursue
> them. It
> laid out their advantages and disadvantages vs. probe and drogue, and
> stated
> that booms definitely had the advantage for large a/c. But we no longer
> operate
> 1,500+ B-47s or even 500+ B-52s in addition to the other odds and sods
> that
> really benefit from B&R. We've got about 100 heavy bombers
Really? Let's see...21 B-2's, 65 B-1B's, 85 B-52's equals 171 in the active
inventory according the the af.mil fact sheets.
and will have 180 or
> so C-17s plus mumblety-odd C-5s and 58 or so KC-10s, plus the odd
> E-3/E-4/E-6
"Odd"? Not when combined--the number of those airframes exceed the number of
combat airframes in many air forces...
> etc.
And EC-135's, RC-135's, E-8's, however many C-130J's... Just adding up those
you named and those I added, you have (126) C-5's, say (180) C-17's
(eventual), (33) E-3, (4) E-4, (17) E-8, (59) KC-10, (3) OC-135's, (16)
RC-135, (2) VC-25, (1) WC-135, (21) AC-130, (say 60, a conservative number
given that Congress keeps the program going whether the USAF wants it or
not) C-130J, plus those 171 heavy bombers, equals a total of some 693, which
does not include the MC-130's... A rather sizable force which you would have
handled by leftover legacy tankers operating in a mixed bag force. Not very
smart IMO.
>
>> Then he
>> followed with his "buy aircraft with hoses, and keep some of the old KC's
>> around to handle the boomers" junk.
>
> Which is one possible (and reasonable) solution among several,
Reasonable my butt. 693 plus airframes, Guy...not to mention the arguments
that the boom is a better way to go for the fighters as well.
and IMO one that
> the USAF and DoD should consider. After an objective analysis they may
> determine that it's not the most cost-effective option, and I won't argue
> with
> that conclusion if I believe that it was honestly arrived at. But
> dismissing it
> out of hand without even running the numbers, when interoperability is
> increasingly important and large-scale tanker and fighter
> re-capitalization is
> going to start soon, would be foolish IMO.
Interoperability is a nonstarter as I mentioned earlier given the solution
being offered of having boomers with pods.
>
> <snip>
>
>> >> > ... then they've lost the boom-refuel capability for that sortie.
>> >> > That
>> >> > poor ol' boom operator's doing a lot of waving recently...
>> >>
>> >> Only the 135; the KC-10 retains full boom capability. And as you
>> >> obviously
>> >> know, the 135's can carry the pods that allow them to handle both
>> >> types
>> >> of
>> >> receivers on the same mission
>> >
>> > IIRR, only 20 or maybe it was 40 (we bought either 40 pods or 40 mod
>> > kits,
>> > I
>> > forget which) KC-135Rs which were so modified.
>>
>> We are talking future options here, Guy.
>
> Yes, and please keep that in mind when considering if we need all our
> tankers to
> be boom-equipped.
Yep, we do, see above.
Exactly. Which the author failed to mention, IIRC...
>
>> > 2. Fighter flights benefit from having multiple refueling points on
>> > the
>> > same
>> > a/c, and can't make use of the maximum flow rate from a boom in any
>> > case.
>>
>> See above.
>
> Ditto.
Why?
Brooks
Guy Alcala
> The only IFR-equipped airplane I've flown is the F4 so I know
> nothing about refueling probe and drogue. I do know from other people's
> experiences it is more difficult than using the boom.
True by all accounts I've read, although see my late night
stream-of-consciousness musings over on the same thread on r.a.m.n.
> I'm not thrilled
> at the idea of losing knots of airspeed and burning more fuel to shove
> an external probe around the sky.
Not an issue that I recall being mentioned (at least, not as a significant
factor) by anyone who's done it..
> I also suspect that thing would
> create noise in the cockpit when on the deck going fast.
Fixed external probes undoubtedly would, and they're obviously out for
stealthy a/c.
> And just how
> is one supposed to incorporate a retractable probe into a fighter not
> designed from the first to have one?
Good thing two out of three versions of our next stealthy fighter have
retractable probes, and the third version's fuselage is apparently near
identical to one of the others, allowing a retractable drogue to be
substituted for the planned receptacle relatively easily;-) And we'd save
money on the cost of drogues by increasing the drogue buy (albeit therpice
or receptacles would likely go up) and not having to pay for separate boom
refueling qualification trials. Comparative maintenance cost data for the
two systems should be available.
> I conclude that a flight of four will be off the tanker faster
> using the boom.
Walt, since you state above that you have no experience of P&D refueling, I
believe Pete Stickney's Sig applies to your conclusion -- "Without data,
all you have is an opinion." ;-)
> IFR on the boom is simple; it's just a matter of
> recognizing where you're supposed to be and staying there. The lights
> then become almost nugatory. As for offload rates, we once tried 8 F4s
> on one KC135. That was a lesson in frustration since as flight lead I
> was back down to where I started before #8 got off the boom. Not that
> the tank was giving us all that much. 7th AF planning was remiss that
> mission . . .
6 a/c per two drogue tanker seems to be fairly routine - I know I've seen
shots of F-18 six-ships during DS doing pre-strike tanking from KC-130s.
Six a/c also seems to be the standard transoceanic deployment cell for USAF
receptacle-equipped a/c. Either Ed told me or I read somewhere that during
RT/LB, standard tanker allocation was 1 per 4 a/c prestrike, 1 per 8
post-strike (presumably many a/c wouldn't need refueling on egress).
> As for speeds - refueling an F4 with a full load of ordnance
> aboard at 25000 generally required going to min AB on one engine when
> half-way through the offload while adjusting the other one somewhat
> below full military to stay in position. Engaging an AB while hooked up
> was always 'interesting'. Another feature of refueling off the
> centerline boom is that the tanker gives a beautiful reference when
> refueling in night weather, not that uncommon back then on Cherry
> anchor. Getting 'towed' through an embedded thunderstorm is an
> experience in frenetic formation flying, too.
> So - screw the academic approach; wing podded drogues and a
> centerline boom is the way to go.
Sure, it's probably ideal. But this being a zero-sum game, if we are
willing to pay for the ideal, what else do we have to give up to get it?
>Always thought two of the principles
> of warfare were flexibility and economy of resources.
Sure are, and interoperability with your allies is a major part of that
flexibility and economy.
> As for refueling
> 3 at once off a KC 10 - just what were the clearances in feet, anyway?
> I wonder if the author knew anything about wingtip clearance in flying
> wing weather. Most likely less than the width of his desk, not to
> mention his posterior. (G) 3x104s would fit very nicely, Guy! So would
> AV8s and A4s (if we still had any.)
As to that, the AV-8B wingspan is 30'4", while IIRR the F-35A/B's is 30
feet (F-35C is 36' IIRR). AV-8A was 25'3.25", A-4 27'6".
> Anytime some academic writes about flying and does not cite
> references and authorities he 's contacted - suspect an axe is being
> ground. tTis one seems to have been quite thoroughly ground - and the
> books cooked, besides.
I see no evidence of books being cooked, just a statement of an alternative
that apparently hasn't been considered. He presents his numbers and says
how they are arrived at, which isn't book-cooking to me. If someone can
come up with numbers that show it isn't the best way to go, fine, but let's
consider our alternatives before we spend several hundred billion on new
tankers and fighters. Hell, RAND just did a (somewhat inconclusive)
analysis of alternatives over how many and what _size_ of tankers we
require, so why not look at how what refueling system to equip them with?
If keeping boom refueling for tactical a/c is such a slam dunk, it should
be easily provable with 50 years of comparative data.
I'm certain booms are very valuable and can be justified for strategic a/c,
my only question is whether they are equally valuable and justified for
tactical a/c. I suspect the dividing line would probably fall somewhere in
the range of routine onloads of 20-30,000 lb. per tanker contact -- if you
typically take less booms are less cost-effective, over that they are more
so. But that's only a guess.
Guy
WaltBJ
prohibition against refuling 3 at once. I adjudged his posterior was
oversized from the tenor of his report. Don't know about yours nor do I
give a damn. (G).
Walt BJ
Kevin Brooks
Okey dokey. I have not seen mine myself in some time, so I can't judge. The
wife just laughs when I "strike a pose" though, which is probably not a good
thing...
Brooks
> Walt BJ
>
WaltBJ
Guy Alcala wrote:
> WaltBJ wrote:
>
> > The only IFR-equipped airplane I've flown is the F4 so I know
> > nothing about refueling probe and drogue. I do know from other people's
> > experiences it is more difficult than using the boom.
> I'm not thrilled
> > at the idea of losing knots of airspeed and burning more fuel to shove
> > an external probe around the sky.
>
> Not an issue that I recall being mentioned (at least, not as a significant
> factor) by anyone who's done it..
And since I do have experience going in to bad guy territory at less
than 50 feet above the water at 550 KIAS I can assure you that an
external probe will rpt will burn more fuel. The fixed probe on the
F104C cost that bird a fair bit of its maximum Mach.
>SNIP
>
> > I conclude that a flight of four will be off the tanker faster
> > using the boom.
>
> Walt, since you state above that you have no experience of P&D refueling, I
> believe Pete Stickney's Sig applies to your conclusion -- "Without data,
> all you have is an opinion." ;-)
>
> Guy, face it. I do have friends who were Hun or Navy pilots and have clued me in on probe and drogue refueling. If a pilot misses a stick on the probe he has to reposition and try again. This is a probability, not a possibility. On the boom you get into position and presto, fuel. I watched my 5 other aircraft in my flight go through about 15 refuelings each on a trans-Pacicific hop and not one of them ever screwed up their initial position nor missed getting hooked up the first time. Now throw in night weather and see how the probabilities work out . . .
SNIP
In my "8 on a tank" recounting - it was pre-strike, and it was lousy
planning.
SNIP
> > I'm certain booms are very valuable and can be justified for strategic a/c,
> my only question is whether they are equally valuable and justified for
> tactical a/c. I suspect the dividing line would probably fall somewhere in
> the range of routine onloads of 20-30,000 lb. per tanker contact -- if you
> typically take less booms are less cost-effective, over that they are more
> so. But that's only a guess.
Guy, there's no way a retractible probe can be incorporated without a
weight space and complication penalty as compared to a receptacle. KISS
applies in an extreme manner to fighter design.
SNIP:
Cost effectiveness: face it: the tanker airplane is by far the more
costly item by several orders of magnitude. It makes no sense to
effectively divide the tanker assets into two fleets. Hanging a drogue
on a boom works but now limits that sortie. Hanging two wing pods on a
boomer affords maximum flexibility at minimal cost. The 'receptacle
force' and the 'drogue force' both require IFR. Why not go the full
route and thus gain maximum flexibility and maximum use of resources?
Kind of reminds me of the same sort of penny-wise pound-foolish
reasoning that put the S3's engines on the A10 thus rendering it
incapable of sustained combat maneuvering when carrying its designed
bomb load.
QED
Walt BJ
Guy Alcala
> Guy Alcala wrote:
> > WaltBJ wrote:
> >
> > > The only IFR-equipped airplane I've flown is the F4 so I know
> > > nothing about refueling probe and drogue. I do know from other people's
> > > experiences it is more difficult than using the boom.
> > SNIP>
> > I'm not thrilled
> > > at the idea of losing knots of airspeed and burning more fuel to shove
> > > an external probe around the sky.
> >
> > Not an issue that I recall being mentioned (at least, not as a significant
> > factor) by anyone who's done it..
>
> And since I do have experience going in to bad guy territory at less
> than 50 feet above the water at 550 KIAS I can assure you that an
> external probe will rpt will burn more fuel.
Sure, a fixed external probe will burn more fuel, but we're not going to be putting them on stealth a/c. Even so, as the report stated the USAF was considering putting them on F-15s and F-16s back about 1990, retaining the receptacles as well, just as the Israelis had done with their F-4Es.
> The fixed probe on the
> F104C cost that bird a fair bit of its maximum Mach.
Naw, that was a book restriction in the -1 because it hadn't been officially tested out to M2.0. According to a friend of a friend who flew them in the 435th at George and in SEA, once the pilots found that out they routinely ignored the placard limit, which IIRR (without searching through my -1 to find it) was M1.75. I did find the stores drag chart -- The external probe on the 104C only added 8.0 drag counts; in comparison, a pair of tip winders and launchers or tip tanks added 10.0, and a pair of wing pylons and wing tanks add a whopping 29.0. So the
added drag of the probe was pretty small.
> >SNIP
> >
> > > I conclude that a flight of four will be off the tanker faster
> > > using the boom.
> >
> > Walt, since you state above that you have no experience of P&D refueling, I
> > believe Pete Stickney's Sig applies to your conclusion -- "Without data,
> > all you have is an opinion." ;-)
> >
> > Guy, face it. I do have friends who were Hun or Navy pilots and have clued me in on probe and drogue refueling. If a pilot misses a stick on the probe he has to reposition and try again. This is a probability, not a possibility.
Sure, I've never disputed that refueling from a boom is easier. And yet they, the British and plenty of other countries' pilots have nevertheless managed to refuel successfully hundreds of thousands of times over the past 50+ years, while the number of failures is orders of magnitude less. And that's using 50-year-old technology -- as mentioned in my previous post, overin thesame thread on r.a.m.n. I suggested the possibility of active drogue stabilisation or even manual control to fly it onto the probe, obviously with the disadvantage of higher price and
complexity. But such capability probably only needs to be used in turbulence, so much of the time using the drogue in 'dumb' mode would be fine.
> On the boom you get into position and presto, fuel. I watched my 5 other aircraft in my flight go through about 15 refuelings each on a trans-Pacicific hop and not one of them ever screwed up their initial position nor missed getting hooked up the first time. Now throw in night weather and see how the probabilities work out . . .
And I'm sure that data is available somewhere, and as soon as someone can present it we'll have more than our opinions to work with;-)
> SNIP
> In my "8 on a tank" recounting - it was pre-strike, and it was lousy
> planning.
And it continues to happen.
> SNIP
> > > I'm certain booms are very valuable and can be justified for strategic a/c,
> > my only question is whether they are equally valuable and justified for
> > tactical a/c. I suspect the dividing line would probably fall somewhere in
> > the range of routine onloads of 20-30,000 lb. per tanker contact -- if you
> > typically take less booms are less cost-effective, over that they are more
> > so. But that's only a guess.
>
> Guy, there's no way a retractible probe can be incorporated without a
> weight space and complication penalty as compared to a receptacle. KISS
> applies in an extreme manner to fighter design.
Sure, and yet it can be successfully done. Actually, both retractable probes and receptacles have been added on externally to a/c which either have the option of removing them when not needed (ex. AV-8B), or (in the case of receptacles) had them permanently added later (ex. C-141B).
> SNIP:
> Cost effectiveness: face it: the tanker airplane is by far the more
> costly item by several orders of magnitude. It makes no sense to
> effectively divide the tanker assets into two fleets. Hanging a drogue
> on a boom works but now limits that sortie. Hanging two wing pods on a
> boomer affords maximum flexibility at minimal cost.
For government values of minimal, about $5.3 million (adjusted to FY2004 dollars; $4.35 mil in 1996 dollars) to add a pair of pods to a KC-135 in 1996. I'm still trying to find the cost of a boom installation, but I imagine it's a lot more than that.
> The 'receptacle
> force' and the 'drogue force' both require IFR. Why not go the full
> route and thus gain maximum flexibility and maximum use of resources?
And if that's the most cost-effective way to go, I agree. So let's have someone run the numbers.
> Kind of reminds me of the same sort of penny-wise pound-foolish
> reasoning that put the S3's engines on the A10 thus rendering it
> incapable of sustained combat maneuvering when carrying its designed
> bomb load.
> QED
BTW, since you accused the author of the study of not providing his sources, let me provide you with the location of the study which includes all the footnotes citing his sources:
www.fas.org/sgp/crs/weapons/RL32910.pdf
His source for the statement that fighters were restricted to 1,000 - 3,000 lb./min transfer rates whether using boom or drogue is listed as "KC-135 Aerial Refueling Procedures Manual T.O. 1-1C-1-3". Not owning a copy I can't check to see if he mis-quoted or mis-interpreted it, but I see that one's available at eflightmanuals.com for $14.95, so if I'm feeling flush I may just break down and order it.
Guy
Guy Alcala
> "Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
> news:44A7ADE7...@junkpostoffice.pacbell.net...
> > Kevin Brooks wrote:
<snip>
> A bit of a stretch to make that claim. The USAF is exclusively boom oriented
> (and has been for many years) with the exception of its helo fleet, and I
> doubt anyone is arguing that the next generation tanker should be optimized
> to handle helo refueling, which will likely remain the domain of the
> specialist MC-130 variants. You don't really envision KC-135/10/767's
> refueling helos, do you?
No, but I do envision them refueling MV/CV-22's, as required by the V-22 ORD.
And as to the mixed fleet, any KC-135 tasked with refueling probe-equipped
receivers without having wing pods is effectively part of that mixed fleet for
that mission, since it can't be re-roled inflight.
BTW, while the restrictions aren't quite as onerous as was the case with JP-4,
the navy really doesn't want shipboard a/c tanked with JP-8 if they can avoid
it, for fire safety reasons. They require any such a/c to burn down to minimum
fuel before landing (which can be pretty awkward if the weather is lousy and the
bolter rate is high), and then they are supposed to be immediately refueled with
JP-5. The tanker AoA put out by RAND also mentions that it may be worthwhile to
have separate tank systems carrying JP-5 and JP-8 onboard any future tankers to
improve interoperability during a flight. That implies that USAF tankers may be
required (at least under normal circumstances) to be loaded with JP-5 rather
than JP-8 on any mission where they are to be tasked with refueling USN/USMC
ship-based a/c. Do any USAF tanker crew types like Curt have experience tanking
carrier-based USN/USMC a/c in non-emergency conditions (i.e. that was your
pre-flight mission tasking), and if so, were you loaded with JP-8 or JP-5?
> >> >> > How about we ask the (rhetorical) question "how many F15Es can a
> >> >> > single
> >> >> > KC10 (with all the bells, whistles, extra dangly bits and go-juice)
> >> >> > simultaneously refuel?"
> >> >>
> >> >> It does not really matter. It can fuel enough to satisfy the mission
> >> >> requirement.
> >> >
> >> > Assuming that more than one isn't on the point of flameout due to fuel
> >> > starvation. A/C have been lost for that reason. And there can also be
> >> > problems
> >> > with flights needing to cycle on and off the boom because of the wait
> >> > time.
> >>
> >> Guy, I think you have some sort of Pavlovian thing going when it comes to
> >> USAF tanker programs.
> >
> > How so?
>
> You get your fangs out whenever the USAF's desires regarding tanking are
> made known.
If you mean that I find the subject of tankers interesting, I plead guilty. But
my fangs aren't out, whether in reference to USAF tanker decisions or anyone
else's. If say the Brits were arguing that they should go to a mixed system
from all P&D I'd want to see their numbers and reasoning too. I have no bias
towards one or the other system, as I will never make use of it, nor do I have
any economic interest (other than whatever minimal % of my taxes goes to
purchase them) as I hold no stock in companies which make them.
I find the suggestions made in this particular study interesting, as it goes
beyond the assumptions that everyone else has made as a matter of course
(including the AoA, which assumed as a base case that all tankers would have
both boom and wing drogues, rather than including _that_ in the alternatives
studied). While I hate to use trendy, usually meaningless buzzwords, it's
thinking outside the box. That doesn't mean that I think the case is proved,
but when the conventional wisdom is so strongly one-sided and based more on
emotional prejudice than objective analysis, as IMO it has been in this thread,
then I will happily make the argument for the other side, without denying that a
good case can be made for the CW.
> >> The USAF has been very happy with the boom system--I
> >> would think that might count for something?
> >
> > Certainly, it served SAC and MAC, where it was really needed, excellently
> > for
> > decades, and worked well for TAC once they got rid of all their probe-only
> > equipped a/c, the F-100C/D/F, F-104C, F-105B, F-5C, A-37 and EB-66 to name
> > six
> > that come to mind.
>
> The F-5C? What was that?
F-5As modified to improve their combat capability (including an external probe,
belly armor, LCOSS, jettisonable pylons, etc.), deployed to SVN in October 1965
for a combat evaluation by USAF under Project Skoshi Tiger. Partly it was to
develop procedures for the coming SVNAF equipping with the F-5, and partly with
the idea that USAF might buy a couple of hundred. The program ran for about 18
months IIRR, at which point the remaining a/c were passed on to the SVNAF, which
had already started to receive new F-5As. Ed's buddy Bob Titus (later a triple
MiG-killer with the 366th TFW, the only US VN pilot to score one each by AIM-7,
AIM-9 and gunpod) was involved with the program.
> The last USAF tactical fighter using the probe was
> retired sometime in the eighties, IIRC, and that is only if you count the
> OA-37's as being "tactical fighters", which is a bit of a stretch.
Sure, but we still had tank them, and we didn't have any KC-135s or KC-10s with
wingpods then. I imagine KC-10s wouldn't have been used (waste of a strategic
tanker), so that meant KC-135s flying dedicated drogue refueling missions. And
then there were our allies and the navy, who we also might need to tank. Our
joint and combined capability (and interest) was still fairly minimal then, as
illustrated by Grenada, but we were increasingly feeling the need.
> >> And is your flame-out ready
> >> fighter going to be well served when he can't hit the basket,
> >
> > Sometimes it just isn't your day.
>
> But you thought it so important when the subject was the boom receiver
> aircraft...
And sometimes it isn't your day on the boom. Shit can happen in either case.
What I want to see is some actual data that shows MTBF of the refueling systems
as a whole.
> >> or the
> >> basket/hose fails (as really happens more than boom failures)?
> >
> > Which is why it's a good thing to have another one handy.
>
> In the event the MTBF for the hoses is multiple times that of the boom, you
> still run a decent chance of being completely NMC.
Sure, and hopefully someone can provide some numbers that show that to be the
case on a fairly frequent (and unacceptable) basis, or show the opposite.
> >> >> > Then, if we want to get to the point that the original author was
> >> >> > trying
> >> >> > to get to, we can ask the question: "How many F18(insert version of
> >> >> > choice
> >> >> > here)s can a single KC10 (with ... etc) simultaneously refuel?"
> >> >>
> >> >> You might be better to ask, "How many F-15E's can an RAF Tristar
> >> >> refuel?"
> >> >> The answer being, of course, zero.
> >> >
> >> > As the F-15Es are currently equipped. See link in other post to Sargent
> >> > Fletcher
> >> > probe tank, and there's likely no technical reason why you couldn't
> >> > mount
> >> > at
> >> > least a fixed probe on the a/c itself.
> >>
> >> Wow. So now we go to all of this troble, and expense, to remedy a
> >> problem...that is not really a problem.
> >
> > Of course it's a problem, of interoperability.
>
> No, it is not. As we have been saying, the answer is to provide the wing
> pods to the boomers, which allows them to service both.
And as _I_ said, that's an answer for the existing fleet, but it may not be
cost-effective or necessary to do so fleet-wide, nor may it be cost-effective or
necessary to provide a boom on every new tanker.
> Nobody with half a
> brain expects the USN refuelers need be able to refuel USAF assets, so the
> interoperability argument becomes meaningless.
Which isn't the issue, it's whether the USAF can refuel all the drogue-equipped
a/c of the USN/USMC and other services, and as a corollary whether every USAF
tanker needs a boom.
> Note that I'm not recommending
> > that we do such a retrofit, as the cheapest solution is to let natural
> > attrition
> > work by ordering new tactical a/c with probes while keeping enough
> > boom-equipped
> > tankers around for the ever-dwindling number of receptacle-equipped a/c.
>
> Bal;derdash--you are back to fielding a mixed future force with part of it
> unable to handle a big chunk of the assets.
Sure, and asI pointed out we operated successfully under such conditions
before. Such chunk to shrink over time through natural attrition, as itdid with
the TAC transition to all-receptacle refueling in the'60s and '70s. Retiring
F-16s and A-10s and replacing them with probe-equipped F-35s, as mentioned in
the study, would eliminate the need to provide refueling for well over 1,000
receptacle-equipped a/c, and thus, also reduce the number of boom-equipped
tankers needed. Re-engining some a/c, as is happening with the C-5 and may
happen with the BUFF, will decrease the need for IFR for many missions, and thus
the number of boom tankers needed to support those a/c.
> If you won't take it from me,
> then listen to Curt's opinion as to how much sense that makes.
I've read Curt's opinion, but it _is_ an opinion, essentially personal and
anecdotal rather than analytical. I don't dismiss it, but neither do I give it
the same weight as a study that actually runs the numbers. So far, to my
knowledge there hasn't been one.
Who discounted it as such, and where is the economic evaluation showing how much
each method would cost? I have seen no such study showing why it's more cost
effective to outfit every USAF jet tanker, current or projected, with wing
drogues as well as booms. Nor have I seen one that says that its more
cost-effective to buy some new tankers with drogues only and use booms for only
strategic a/c, I have read one CRS report that suggests that it might be.
I _have_ read the RAND AoA that reaches several other conclusions about what
kind of tankers we might buy, but unfortunately only the executive summary
appears to be online so it doesn'tinclude the cost data and methodology used.
>> >> OTOH, the KC-10 can fuel one F-15E at a
> >> >> time, and two F/A-18's at a time (three has been demonstrated, but as
> >> >> another poster noted that is likely not acceptable for normal
> >> >> operations).
> >> >
> >> > And having the choice is definitely the best option for the USAF, and
> >> > the
> >> > report
> >> > never disputes that.
> >>
> >> Gee, that whole first part made it sound like booms were just a real
> >> waste,
> >> and the USAF is the only organization foolish enough to pursue them.
> >
> > It didn't sound like that to me (of course, I read the whole report),
>
> You need to go back and read the first part where he claims that only the
> USAF operated boom receiver aircraft,
I can find no such statement. Care to point me to it?
> implied that NATO was all probe based,
Which, in the aggregate, is essentially true. In another post I listed all the
NATO countries I could think of that had tankers of their own, and the type of
refueling they could do. IIRR, I came up with
6 who used P&D (Canada, France, Germany, UK, Italy, Spain), one that used Boom
(Netherlands), 1 that would soon have boom capability (in addition to drogue:
Italy), and 1 that hoped to get boom (Turkey). I asked if anyone could think
of others, but no one has added any so far. Other countries that operate F-4s
or F-16s have receptacles, but unless they regularly practice AARs with them
(and they'd have to use USAF or Dutch tankers), the capability is somewhat
illusory. When you look at the countries who have actually been willing to fly
combat missions with us and the number of a/c (including tankers) each has
provided, the imbalance of NATO towards drogue refueling is even more
pronounced. Subtract Deny Flight/OAF from the mix and it gets even more
lopsided.
In the Middle East booms are a higher percentage,owing to our having sold F-4s,
F-15s and F-16s fairly widely. Indeed, the second Air Force operator of
boom-equipped tankers and receivers was Iran.
In the Pacific things are a bit more balanced. Japan, Singapore and soon OZ
will all have boom-tankers
>and drew some questionable conclusions about the value of the boom to
> fighter aircraft.
And those conclusions are subject to argument and refutation, with data. But
please note the source cited for his comments re fuel flow rates, the KC-135
aerial refueling manual.
> and it
> > certainly never stated or intimated that the USAF was foolish to pursue
> > them. It
> > laid out their advantages and disadvantages vs. probe and drogue, and
> > stated
> > that booms definitely had the advantage for large a/c. But we no longer
> > operate
> > 1,500+ B-47s or even 500+ B-52s in addition to the other odds and sods
> > that
> > really benefit from B&R. We've got about 100 heavy bombers
>
> Really? Let's see...21 B-2's, 65 B-1B's, 85 B-52's equals 171 in the active
> inventory according the the af.mil fact sheets.
I thought we'd mothballed a fair number of BUFFS, but will happily accept your
figures.
> and will have 180 or
> > so C-17s plus mumblety-odd C-5s and 58 or so KC-10s, plus the odd
> > E-3/E-4/E-6
>
> "Odd"? Not when combined--the number of those airframes exceed the number of
> combat airframes in many air forces...
>
> > etc.
>
> And EC-135's, RC-135's, E-8's, however many C-130J's...
Which was the etc.
> Just adding up those
> you named and those I added, you have (126) C-5's, say (180) C-17's
> (eventual), (33) E-3, (4) E-4, (17) E-8, (59) KC-10, (3) OC-135's, (16)
> RC-135, (2) VC-25, (1) WC-135, (21) AC-130, (say 60, a conservative number
> given that Congress keeps the program going whether the USAF wants it or
> not) C-130J, plus those 171 heavy bombers, equals a total of some 693, which
> does not include the MC-130's...
His cited the current total, direct from the USAF office of Congressional
Liaison, as 669, so we've got no argument.
> A rather sizable force which you would have
> handled by leftover legacy tankers operating in a mixed bag force. Not very
> smart IMO.
Sure it's a sizable force, and we need to provide enough boom tankers to cover
them, but it's still only 669 out of 3,227 a/c or 20.7% that really _need_ a
boom. Subtracting the 139 helos (4.3%) that presumably can't use a boom for
safety reasons, we're left with 2,419 a/c (75%) that will work fine with
either. The USAF is currently planning to buy perhaps 1,200 F-35As and (maybe)
Bs, the former can be equipped with whichever method they chose with little
hassle, and these a/c are programmed to replace perhaps 1,700 F-16s and A-10s.
The F-22 is probably too far along to change to a probe at minimal cost now, so
we've got say 183 which will probably replace some greater number of F-15s
eventually. So we can look forward to the USAF eventually needing to provide
boom tankers for +-852 a/c, assuming no significant numerical changes in the 669
or 693 (if you prefer) heavies. Plus a certain allowance for boom-equipped
allies, although increasingly they've got their own tankers.
> >> Then he
> >> followed with his "buy aircraft with hoses, and keep some of the old KC's
> >> around to handle the boomers" junk.
> >
> > Which is one possible (and reasonable) solution among several,
>
> Reasonable my butt.
Which is a matter of opinion, worth as much or little as mine is.
> 693 plus airframes, Guy...
669 or 693, out of 3,227. So, to summarise, you feel it's reasonable to buy a
more expensive type of refueling equipment and equip 100% of the new tankers we
will buy with it in addition to two wing drogues, to refuel ca. 21% of the force
that really needs that more expensive method (oh, and use more fuel to
compensate for the extra drag of the boom, for the next 50 years or so), while I
think it's arguable whether that is the most reasonable, cost-effective
solution, and someone should do a proper life-cycle analysis to find out.
> not to mention the arguments
> that the boom is a better way to go for the fighters as well.
And there are advantages and disadvantages on both sides of that argument. If I
had to summarise the main advantages re fighters, they would be:
Booms are easier to refuel from currently, more reliable (at least singly), and
allow higher transfer rates for those a/c which can accept them.
Drogues are (currently) cheaper and easier to install on a wide variety of a/c,
can (currently) be installed in multiple on one a/c, and can be used for buddy
tanking.
> and IMO one that
> > the USAF and DoD should consider. After an objective analysis they may
> > determine that it's not the most cost-effective option, and I won't argue
> > with
> > that conclusion if I believe that it was honestly arrived at. But
> > dismissing it
> > out of hand without even running the numbers, when interoperability is
> > increasingly important and large-scale tanker and fighter
> > re-capitalization is
> > going to start soon, would be foolish IMO.
>
> Interoperability is a nonstarter as I mentioned earlier given the solution
> being offered of having boomers with pods.
But the question isn't whether or not the USAF tanker fleet will be more
interoperable, because it will be in the future; there is no argument on that
point whatsoever. The question raised by the study is, what is the most
cost-effective way to achieve that interoperability?
> > <snip>
> >
> >> >> > ... then they've lost the boom-refuel capability for that sortie.
> >> >> > That
> >> >> > poor ol' boom operator's doing a lot of waving recently...
> >> >>
> >> >> Only the 135; the KC-10 retains full boom capability. And as you
> >> >> obviously
> >> >> know, the 135's can carry the pods that allow them to handle both
> >> >> types
> >> >> of
> >> >> receivers on the same mission
> >> >
> >> > IIRR, only 20 or maybe it was 40 (we bought either 40 pods or 40 mod
> >> > kits,
> >> > I
> >> > forget which) KC-135Rs which were so modified.
> >>
> >> We are talking future options here, Guy.
> >
> > Yes, and please keep that in mind when considering if we need all our
> > tankers to
> > be boom-equipped.
>
> Yep, we do, see above.
Likewise. Well, we know we disagree;-)
<snip>
Incorrect, he did. He quoted figures from the KC-135, IIRR 2,000 lb/in. for the
drogue, 3,000 lb./min. for the boom. I don't know if that only included the
add-on or the Mk.32 wingpods, which have max. flow rates up to 470 USG/min
according to the sources I found, but the flow rate may be restricted by the
diameter of the fighter's probe rather than what the pod can pump.
> >> > 2. Fighter flights benefit from having multiple refueling points on
> >> > the
> >> > same
> >> > a/c, and can't make use of the maximum flow rate from a boom in any
> >> > case.
> >>
> >> See above.
> >
> > Ditto.
>
> Why?
Again, we have conflicting sources about just what the maximum flow rates for
each method are, and how much of that is usable by fighters.
Guy
Kevin Brooks
> Kevin Brooks wrote:
>
>> "Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
>> news:44A7ADE7...@junkpostoffice.pacbell.net...
>> > Kevin Brooks wrote:
>
> <snip>
<snip again due to lack of time>
>> >>
>> >> Gee, that whole first part made it sound like booms were just a real
>> >> waste,
>> >> and the USAF is the only organization foolish enough to pursue them.
>> >
>> > It didn't sound like that to me (of course, I read the whole report),
>>
>> You need to go back and read the first part where he claims that only the
>> USAF operated boom receiver aircraft,
>
> I can find no such statement. Care to point me to it?
"Currently, Air Force fixed-wing aircraft refuel with the "flying boom...Air
Force helicopters, and all Navy and Marine Corps aircraft refuel using the
"hose-anddrogue. NATO countries and other allies also refuel with the
hose-and drogue." From the early part of his "study". Now just what the heck
conclusion do YOU draw from that? Where did he identify any other service
aircraft that use the boom (like the E-6), and where did he acknowledge that
other air forces also use the boom (they do, and the number is *growing*)?
>
>> implied that NATO was all probe based,
>
> Which, in the aggregate, is essentially true. In another post I listed
> all the
> NATO countries I could think of that had tankers of their own, and the
> type of
> refueling they could do. IIRR, I came up with
> 6 who used P&D (Canada, France, Germany, UK, Italy, Spain), one that used
> Boom
> (Netherlands), 1 that would soon have boom capability (in addition to
> drogue:
> Italy), and 1 that hoped to get boom (Turkey). I asked if anyone could
> think
> of others, but no one has added any so far.
Turkey already has the KC-135, Guy. I told you that earlier. "The KC-135 is
also in service with the air forces of France (11 aircraft), Turkey (seven)
and Singapore (four)."
www.airforce-technology.com/projects/kc135/
I also noted that Japan has selected the boom. And Australia has opted for
booms on its Airbus tankers that are to replace the current 707's.
Other countries that operate F-4s
> or F-16s have receptacles, but unless they regularly practice AARs with
> them
> (and they'd have to use USAF or Dutch tankers), the capability is somewhat
> illusory. When you look at the countries who have actually been willing
> to fly
> combat missions with us and the number of a/c (including tankers) each has
> provided, the imbalance of NATO towards drogue refueling is even more
> pronounced. Subtract Deny Flight/OAF from the mix and it gets even more
> lopsided.
As pointed out above, your data is not correct in the first place, and it
ignores the fact that of the last four large tanker aircraft deals (UK,
Italy, Japan, and Australia), three of them opted for booms.
>
> In the Middle East booms are a higher percentage,owing to our having sold
> F-4s,
> F-15s and F-16s fairly widely. Indeed, the second Air Force operator of
> boom-equipped tankers and receivers was Iran.
>
> In the Pacific things are a bit more balanced. Japan, Singapore and soon
> OZ
> will all have boom-tankers
Exactly.
Don't have time for anything more right now...
Brooks
Holy crap, man. You acknowledge that at least one-fifth of the force is
going to be boomers, and yet you figure that is an insignificant portion
when it comes to ensuring that the tanker force at large can support them? I
find that completely illogical.
Brooks
<snip>
Ed Rasimus
<broo...@notyahoo.com> wrote:
>
>"Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
>news:44A92996...@junkpostoffice.pacbell.net...
---Extensive bureaucratic bovine scatology snipped in order to cut to
the chase---
We started this discussion with a petty bureaucrats "study" flogging
probe/drogue tankers for the future and have wandered far afield with
first requests for comments from BTDT types and then disregard for
what they recount.
Let me list a few issues (I hesitate to put them forward as "facts"
lest some GAO functionary should discount them as contrary to his/her
"study".)
1.) There is a large fleet of US aircraft that employ boom-receptacle
refueling. This fleet will not be instantly replaced and the need for
legacy compatibility is going to be a compelling part of any argument.
2.) While drogues are "cheap" and booms are expensive, a major issue
is that probes for modern military aircraft must be retractable and
that means considerable plumbing and a lot of valuable airframe space
taken up with the mechanism.
3.) Receptacles are small and integrate very easily with the single
point refueling system of modern aircraft. (No one would make a
similar argument to the boom vs probe discussion for replacing
single-point systems with over-the-wing hoses.)
4.) Boom refueling is considerably faster than probe/drogue in terms
of both hook-up and off-load rate. Transfers of two to four times the
flow make a significant difference.
5.) Boom refueling is relatively unaffected by weather, visibility,
turbulence and tanker/receiver aerodynamic interference while
probe/drogue is subject to issues in all of those areas.
6.) Crew workload is considerably lower for boom systems.
7.) While USN/USMC have used probe-drogue for years, they typically
(prior to current conflicts) refueled with buddy systems and used
relatively small transfer volumes in which rate and reliability were
not critical. Conversely, both strategic and tactical USAF systems
have required considerably greater offloads which leads to a
requirement for a higher throughput.
8.) Probes are inherently more complex and vulnerable than receptacle
slipways. Drogues with the attendant rubber hose are similarly more
vulnerable to damage and deterioration than the boom system.
9.) Boom receptacle systems allow for considerably higher refueling
speeds than probe/drogue which minimizes issues of aircraft
compatibililty and high AoA operations at heavy receiver gross
weights.
There are good reasons why the USAF has used booms for years, not the
least of which was that for a long time the technology was superior to
that of many other nations. We could, so we did.
With a modern force that relies on speed, stealth, economy of force,
and long-range projection of power it would be an unusual decision
indeed to return to 1950's technology and start dragging hoses around
behind aircraft again.
Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
www.thunderchief.org
www.thundertales.blogspot.com
dyna...@vianet.on.ca
Ed Rasimus wrote:
[snipped all good points]
> With a modern force that relies on speed, stealth, economy of force,
> and long-range projection of power it would be an unusual decision
> indeed to return to 1950's technology and start dragging hoses around
> behind aircraft again.
> Ed Rasimus
> Fighter Pilot (USAF-Ret)
> "When Thunder Rolled"
> www.thunderchief.org
> www.thundertales.blogspot.com
"modern force", that would include refueling
Remotely Piloted Vehicles, though I don't
know if that's been done(?), checked,
http://en.wikipedia.org/wiki/Aerial_refueling
anyone know?
It also says a boom can be converted to
hose operations but NOT the other way
around.
So with 3 booms, one centerline and two
in wing tip pods, everybody's happy until
drogue is phased out if it ever is.
That could be done when the boom method
is computerized, which eliminates the boom
operator, enabling smaller carrier based a/c
to use a boom from a single seat tanker.
Tactically, an RPV able to be refuelled has
a unlimited endurance, and if over a hostile
region can fly back to a safer location to
the refueler, in safer air space.
Stealthy RPV's hanging over an aggressor
or potential aggressor would certainly be
confounding and a good deterrent and
would cost more to shoot down than the
RPV is worth, especially if some RPV's
were specifically cheap decoys.
Strategically having that ability is a peace
tool.
When Ed uses the phrase "modern force"
electronics in 10-20 years needs to be
considered, considering the physics of
airframes and engines is very nearly peaked,
electronics control and cheap recon intel will
likely become a decisive factor.
Regards
Ken S. Tucker
Peter Stickney
Let's also not forget Iran, with their boom equipped Boeing 707s and 747s,
and Saudi Arabia with their 707 tankers (KE-3s, albeit without the Radar
Stuff and the Frisbee)
--
Pete Stickney
Guy Alcala
> On Mon, 3 Jul 2006 10:58:14 -0400, "Kevin Brooks"
> <broo...@notyahoo.com> wrote:
>
> >
> >"Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
> >news:44A92996...@junkpostoffice.pacbell.net...
>
> ---Extensive bureaucratic bovine scatology snipped in order to cut to
> the chase---
>
> We started this discussion with a petty bureaucrats "study" flogging
> probe/drogue tankers for the future and have wandered far afield with
> first requests for comments from BTDT types and then disregard for
> what they recount.
No, just a question of this being a largely USAF forum, while the navy
types are mostly over on r.a.m.n.
> Let me list a few issues (I hesitate to put them forward as "facts"
> lest some GAO functionary should discount them as contrary to his/her
> "study".)
>
> 1.) There is a large fleet of US aircraft that employ boom-receptacle
> refueling. This fleet will not be instantly replaced and the need for
> legacy compatibility is going to be a compelling part of any argument.
Certainly, and the same was true from the early 60s to the late '70s-early
'80s, when it took TAC over 20 years to finally phase out their last
P&D-equipped a/c. At the start of 1979, there were still 10 ANG squadrons
flying the Hun. Not sure when the last OA-37 shuffled off.
> 2.) While drogues are "cheap" and booms are expensive, a major issue
> is that probes for modern military aircraft must be retractable
'Must be' for stealth a/c; 'nice to have' for everyone else.
> and
> that means considerable plumbing and a lot of valuable airframe space
> taken up with the mechanism.
Fortunately for us, the largest future tactical fighter procurement
program we have going has already incorporated the plumbing and the space,
and in two out of three versions the actual installation.
> 3.) Receptacles are small and integrate very easily with the single
> point refueling system of modern aircraft.
Agreed.
> (No one would make a
> similar argument to the boom vs probe discussion for replacing
> single-point systems with over-the-wing hoses.)
Not sure what your meaning is here -are you talking about
pressure-refueling vs. gravity? If so, that's not an issue, since either
AAR method uses single-point.
> 4.) Boom refueling is considerably faster than probe/drogue in terms
> of both hook-up and off-load rate. Transfers of two to four times the
> flow make a significant difference.
Assuming that they are that different now. The report cites the KC-135
refueling procedures manual as having fighter transfer rates to 1 to 3,000
lb./min., with the boom capable of the higher figure and the drogue
limited to 2,000 lb. min. It's unclear to me if that refers to the add-on
drogue or the more modern wing pods, which are credited with max. transfer
rates of 470 gal./min., or about 3,150 lb./min. of JP-8/ just under 50 lb.
more of JP-5.
> 5.) Boom refueling is relatively unaffected by weather, visibility,
> turbulence and tanker/receiver aerodynamic interference while
> probe/drogue is subject to issues in all of those areas.
True given the current systems. Whether that needs to be the case for P&D
given modern technology, I don't know.
> 6.) Crew workload is considerably lower for boom systems.
I presume you're referring to the aircrew of the receiver, not the tanker.
Can't get much lower workload than "1. Set the transfer amount. 2. Unreel
hose. 3. Repeat Step 1 as needed. 4. Retract hose." Single pilots
carrying buddy stores have been doing that for 50 years now.
> 7.) While USN/USMC have used probe-drogue for years, they typically
> (prior to current conflicts) refueled with buddy systems
While they used buddy systems when nothing else was available, the crews
of USN carrier-based AJs, KA-3Ds and KA-6s, and the pilots who routinely
tanked from them would disagree with you (not to mention the crews of the
R3Y Tradewind, AFAIK the only four-point tanker ever to enter service:
http://en.wikipedia.org/wiki/Image:R3Y_Tradewind_refuelling.jpg
And so would the USMC pilots who've been using the KC-130 as their primary
tanker for almost 50 years now.
> and used
> relatively small transfer volumes in which rate and reliability were
> not critical.
Depends on where they were. In Vietnam or the Med, often true. In the
Gulf or on transoceanic deployments, definitely not true.
> Conversely, both strategic and tactical USAF systems
> have required considerably greater offloads which leads to a
> requirement for a higher throughput.
See above. USAF strategic systems, no argument.
> 8.) Probes are inherently more complex and vulnerable than receptacle
> slipways. Drogues with the attendant rubber hose are similarly more
> vulnerable to damage and deterioration than the boom system.
Agreed.
> 9.) Boom receptacle systems allow for considerably higher refueling
> speeds than probe/drogue which minimizes issues of aircraft
> compatibililty and high AoA operations at heavy receiver gross
> weights.
Don't know about that - even if it was true once it may no longer be.
> There are good reasons why the USAF has used booms for years, not the
> least of which was that for a long time the technology was superior to
> that of many other nations. We could, so we did.
The main reason was that SAC was designated as the sole tanker operator in
the early '60s and they needed the boom for their own ops, so that's what
TAC had to accept (apparently TAC preferred to stay with P&D; their KB-50s
were three-point tankers, although I'm sure they would have preferred
something with more speed). I picked the first photo just for you, Ed ;-)
http://www.wpafb.af.mil/museum/research/bombers/b4/kb50j-4.jpg
This one's for WaltBJ:
http://www.wpafb.af.mil/museum/research/bombers/b4/kb50j-5a.jpg
And this one's for any old Hun drivers:
http://www.wpafb.af.mil/museum/research/bombers/b4/kb50j-13.jpg
More photos here:
http://www.wpafb.af.mil/museum/research/bombers/b4/b4-56.htm
> With a modern force that relies on speed, stealth, economy of force,
> and long-range projection of power it would be an unusual decision
> indeed to return to 1950's technology and start dragging hoses around
> behind aircraft again.
Ed, both P&D and boom were developed in the late '40s; I'd have to check,
but I think P&D was developed by Flight Refueling slightly after the boom
was developed by Boeing. The first in-flight hook up (no fuel transfer)
using P&D occurred on April 4th, 1949. A 2002 article in "BoeingNews"
says that in "1948 Boeing developed the 'flying boom.' 1950. Flying boom
entered production on the KB-29P."
www.boeing.com/commercial/767family/pdf/767tanker.pdf
And the USAF has never stopped 'dragging hoses around behind a/c', nor are
they likely to. Indeed, as noted repeatedly in the course of this thread,
they are almost certainly going to increase the number of hose and drogue
units substantially.
Guy
P.S. It turns out that someone has started to compare the costs:
www.gao.gov/new.items/d05316r.pdf
I note the Lockmart estimate that installing probes instead of receptacles
on all the USAF F-35As would save about $180 million, lalmost all of it
owing to lower parts costs.
Guy Alcala
Kevin, I've been out of town for a couple of days, and it's late. I'll get to
your messages when I can, but it may be a few days depending on how things go
with real life. Replying to your messages always takes me a bit longer, as our
exchanges tend to approach novelette length. ;-)
Guy
Guy Alcala
Yeah, I know, but I don't foresee us doing Joint ops with the Iranians anytime
soon ;-), and I expect the Saudis will want to keep us at arm's length
(publicly) for quite a while yet, given their political issues.
Guy
tscottme
When I was working for an airline some time ago, having dual or triple
systems on an airplane often meant "more likely to have a write-up". The
plane could fly perfectly well with one autopilot. It may have 3
autopilots. However if only one or two autopilots were operable, the
aircraft had flight limitations including a limited number of takeoff cycles
before repair. So the net effect of having redundant systems was inflight
redundancy, to continue a flight in progress, but more likely to have a
flight limitation before takeoff on any given day.
--
Scott
Democrats: "We give more aid and comfort to the enemy before 9 a.m. than
most people give all day."
"Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
news:44A7A007...@junkpostoffice.pacbell.net...
Guy Alcala
> Can you dispatch a tanker with dual drogues if one drogue system is inop?
> When I was working for an airline some time ago, having dual or triple
> systems on an airplane often meant "more likely to have a write-up". The
> plane could fly perfectly well with one autopilot. It may have 3
> autopilots. However if only one or two autopilots were operable, the
> aircraft had flight limitations including a limited number of takeoff cycles
> before repair. So the net effect of having redundant systems was inflight
> redundancy, to continue a flight in progress, but more likely to have a
> flight limitation before takeoff on any given day.
Which is why the military has ground spare a/c ready to go. The military
operates their cargo/tanker a/c on a much lower hours/cycles per year rate than
civilian carriers do, something like 10%, which is why they have a reasonable
expectation of being able to operate KC-135s for 80 or even 90 years. Indeed,
one study recommended that they retire some of the oldest KC-135Es and reassign
the crews to newer KC-135Rs, achieving a higher utilization rate of the latter
with fewer MMH/FH than the equivalent number of hours on the KC-135Es.
Naturally, this would wear out the Rs sooner requiring replacement at an earlier
date, but it would also eliminate many of the 'orphan a/c' spares supply
problems that the USAF is worrying about (as is an issue with buying the B-767
or A330), owing to keeping a/c modified from civilian types in service far
longer than the commercial carriers will.
Guy
Guy Alcala
> "Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
> news:44A92996...@junkpostoffice.pacbell.net...
> > Kevin Brooks wrote:
> >
> >> "Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
> >> news:44A7ADE7...@junkpostoffice.pacbell.net...
> >> > Kevin Brooks wrote:
> >
> > <snip>
>
> <snip again due to lack of time>
Sounds good to me;-)
> >> >> Gee, that whole first part made it sound like booms were just a real
> >> >> waste,
> >> >> and the USAF is the only organization foolish enough to pursue them.
> >> >
> >> > It didn't sound like that to me (of course, I read the whole report),
> >>
> >> You need to go back and read the first part where he claims that only the
> >> USAF operated boom receiver aircraft,
> >
> > I can find no such statement. Care to point me to it?
>
> "Currently, Air Force fixed-wing aircraft refuel with the "flying boom...Air
> Force helicopters, and all Navy and Marine Corps aircraft refuel using the
> "hose-anddrogue. NATO countries and other allies also refuel with the
> hose-and drogue." From the early part of his "study". Now just what the heck
> conclusion do YOU draw from that?
That's it's true for the US, and essentially true for NATO.
> Where did he identify any other service
> aircraft that use the boom (like the E-6),
It's a report, not an exhaustive survey inculding all the minutiae.
>and where did he acknowledge that
> other air forces also use the boom (they do, and the number is *growing*)?
Yes they do, but that's because they are operating USAF a/c and/or they are
relying on us to bail them out, so interoperability is key for them. I'd put
Singapore and Oz in that category, and they and Saudi Arabia are dual capable,
because they have a/c using both P&D and Boom. As long as the USAF has a/c that
need booms, Oz is likely to keep theirs even after the F-111 goes away, although
they'd probably do so now in any case owing to Wedgetail and the C-17s they plan
to buy. I know Japan and the Netherlands have bought boom-only tankers; not
sure about Turkey. Japan's totally dependent on USAF-type combat a/c, and
currently so is the Netherlands.
> >> implied that NATO was all probe based,
> >
> > Which, in the aggregate, is essentially true. In another post I listed
> > all the
> > NATO countries I could think of that had tankers of their own, and the
> > type of
> > refueling they could do. IIRR, I came up with
> > 6 who used P&D (Canada, France, Germany, UK, Italy, Spain), one that used
> > Boom
> > (Netherlands), 1 that would soon have boom capability (in addition to
> > drogue:
> > Italy), and 1 that hoped to get boom (Turkey). I asked if anyone could
> > think
> > of others, but no one has added any so far.
>
> Turkey already has the KC-135, Guy. I told you that earlier. "The KC-135 is
> also in service with the air forces of France (11 aircraft), Turkey (seven)
> and Singapore (four)."
I missed that, and my source was out of date. Thanks. IIRR Turkey has the
largest fleet of F-16s outside the USAF, even eclipsing Israel, plus quite a few
F-4s.
> www.airforce-technology.com/projects/kc135/
>
> I also noted that Japan has selected the boom.
Sure, see above.
> And Australia has opted for
> booms on its Airbus tankers that are to replace the current 707's.
Ditto.
> Other countries that operate F-4s
> > or F-16s have receptacles, but unless they regularly practice AARs with
> > them
> > (and they'd have to use USAF or Dutch tankers), the capability is somewhat
> > illusory. When you look at the countries who have actually been willing
> > to fly
> > combat missions with us and the number of a/c (including tankers) each has
> > provided, the imbalance of NATO towards drogue refueling is even more
> > pronounced. Subtract Deny Flight/OAF from the mix and it gets even more
> > lopsided.
>
> As pointed out above, your data is not correct in the first place, and it
> ignores the fact that of the last four large tanker aircraft deals (UK,
> Italy, Japan, and Australia), three of them opted for booms.
Three have opted for dual capability. Italy has them primarily because of her
F-16s (the Tornados use P&D). Japan is the sole boom-only operator, and given
that she has a large fleet of F-4s, F-2s, F-15s, 767 AWACS and probably someday
F-22s, boom-only makes sense for her, even though only the AWACs really needs
it. Oz is about the only other Pacific nation that actually has enough large
a/c (or plans for same), and is far enough away from potential deployment
locations to _need_ booms, regardless of which tactical a/c replaces her F-111s
and F-18s. For Singapore, barring modification of her F-16s she needs the booms
for them, and they allow her to interoperate with Oz, Thailand, Indonesia as
well as the US. The KC-135 and KC-130B wing pod drogues are necessary for her
A-4s and F-5s, as well as Malaysian and Oz F-18s.
> > In the Middle East booms are a higher percentage,owing to our having sold
> > F-4s,
> > F-15s and F-16s fairly widely. Indeed, the second Air Force operator of
> > boom-equipped tankers and receivers was Iran.
> >
> > In the Pacific things are a bit more balanced. Japan, Singapore and soon
> > OZ
> > will all have boom-tankers
>
> Exactly.
Yes, but see above for the reasons, and how many of their a/c really need booms.
Guy
Alistair Gunn
> The plane could fly perfectly well with one autopilot. It may have
> 3 autopilots. However if only one or two autopilots were operable,
> the aircraft had flight limitations including a limited number of
> takeoff cycles before repair.
... but those are presumably either airline or manufacturer limits rather
the plane somehow being unable to physically take-off if one of the
autopilots was non-functional?
--
These opinions might not even be mine ...
Let alone connected with my employer ...
Kevin Brooks
I get the "NATO only uses the hose" read from that, which is not true.
>
>> Where did he identify any other service
>> aircraft that use the boom (like the E-6),
>
> It's a report, not an exhaustive survey inculding all the minutiae.
If he is going to go to the trouble of pointing out those who use the hose,
he should have also pointed out those who use the boom and not make the
inferrence that NATO and the rest of the world only use the hose.
>
>>and where did he acknowledge that
>
>> other air forces also use the boom (they do, and the number is
>> *growing*)?
>
> Yes they do, but that's because they are operating USAF a/c and/or they
> are
> relying on us to bail them out, so interoperability is key for them.
Which he ignored, which made it less than accurate.
I'd put
> Singapore and Oz in that category, and they and Saudi Arabia are dual
> capable,
> because they have a/c using both P&D and Boom. As long as the USAF has
> a/c that
> need booms, Oz is likely to keep theirs even after the F-111 goes away,
> although
> they'd probably do so now in any case owing to Wedgetail and the C-17s
> they plan
> to buy. I know Japan and the Netherlands have bought boom-only tankers;
> not
> sure about Turkey.
Turkey appears to be completely boom based.
Japan's totally dependent on USAF-type combat a/c, and
> currently so is the Netherlands.
No, Japan is not "totally" dependent on USAF combat aircraft types. The
JASDF also operates their own indigenous designs. The F-1 and F-2 are both
indigenous designs, though the latter was based upon the F-16 (albeit with
significant modifications and scaling).
Yep. With booms included. The same dual capability that makes better sense
for the USAF as well.
See how many of the latest orders for tankers involve that dual capability
that you are questioning the wisdom of.
Brooks
>
> Guy
>
Guy Alcala
> "Guy Alcala" <g_al...@junkpostoffice.pacbell.net> wrote in message
> news:44AF8398...@junkpostoffice.pacbell.net...
> > Kevin Brooks wrote:
<snip>
> >> >> You need to go back and read the first part where he claims that only
> >> >> the
> >> >> USAF operated boom receiver aircraft,
> >> >
> >> > I can find no such statement. Care to point me to it?
> >>
> >> "Currently, Air Force fixed-wing aircraft refuel with the "flying
> >> boom...Air
> >> Force helicopters, and all Navy and Marine Corps aircraft refuel using
> >> the
> >> "hose-anddrogue. NATO countries and other allies also refuel with the
> >> hose-and drogue." From the early part of his "study". Now just what the
> >> heck
> >> conclusion do YOU draw from that?
> >
> > That's it's true for the US, and essentially true for NATO.
>
> I get the "NATO only uses the hose" read from that, which is not true.
Then we draw different reads; I consider the statement essentially true,
especially when taking into account those countries that are actually likely to
assists us out of area.
> >> Where did he identify any other service
> >> aircraft that use the boom (like the E-6),
> >
> > It's a report, not an exhaustive survey inculding all the minutiae.
>
> If he is going to go to the trouble of pointing out those who use the hose,
> he should have also pointed out those who use the boom and not make the
> inferrence that NATO and the rest of the world only use the hose.
I consider it trivia, but will happily concede the point..
> >>and where did he acknowledge that
> >
> >> other air forces also use the boom (they do, and the number is
> >> *growing*)?
> >
> > Yes they do, but that's because they are operating USAF a/c and/or they
> > are
> > relying on us to bail them out, so interoperability is key for them.
>
> Which he ignored, which made it less than accurate.
Less than 100% accurate, sure.
> I'd put
> > Singapore and Oz in that category, and they and Saudi Arabia are dual
> > capable,
> > because they have a/c using both P&D and Boom. As long as the USAF has
> > a/c that
> > need booms, Oz is likely to keep theirs even after the F-111 goes away,
> > although
> > they'd probably do so now in any case owing to Wedgetail and the C-17s
> > they plan
> > to buy. I know Japan and the Netherlands have bought boom-only tankers;
> > not
> > sure about Turkey.
>
> Turkey appears to be completely boom based.
Makes sense given their a/c mix.
> Japan's totally dependent on USAF-type combat a/c, and
> > currently so is the Netherlands.
>
> No, Japan is not "totally" dependent on USAF combat aircraft types. The
> JASDF also operates their own indigenous designs. The F-1 and F-2 are both
> indigenous designs,
AFAIK, the F-1 isn't equipped for IFR. Are there any still in service? I
thought the F-2 was supposed to replace them.
>Though the latter was based upon the F-16 (albeit with
> significant modifications and scaling).
I consider the F-2 an F-16 on steroids, but I acknowledge my inaccuracy. Don't
think it matters re my main point, as the entire rest of the combat fleet (any
F-1s aside) are USAF designs.
<snip>
And I've never claimed that it wasn't the ideal solution for the USAF, just that
it might not be the most cost-effective solution.
Again, I've never questioned the wisdom of the dual capability, if you've got
both types. I've questioned the wisdom of using boom refueling on future USAF
tactical a/c, and whether we need booms on every tanker, given the cost. Even
the USAF tanker Mission Needs Statement doesn't state that all new tankers must
have booms and wing pods, only that they all have booms and separate centerline
drogues, to allow them to refuel either type of a/c in the same sortie. Some
a/c should be capable of having wing drogues added, but it doesn't need to be
universal across the fleet. This provides universal emergency capability, but
its less than ideal for refueling flights of probe-equipped fighters.
Since we're going to need several hundred tankers and will apparently buy them
in blocks of 100 or so, then (assuming the USAF shifts to P&D for tactical a/c),
I imagine we might want to buy the first batch of 100 with booms, centerline
drogues and provision for wing drogues; the second or maybe third batch the same
except fitted for but not with booms to give us flexibility to retrofit later
(depending on how swiftly the transition is going), and the final batch(es) with
drogues only. Hauling either wing drogues or booms around when we don't need
them just wastes fuel due to drag. Whether it makes more sense to retrofit more
KC-135Rs with wing drogue capability, or just put them on the new tankers would
need a cost-analysis.
I imagine we've got enough KC-10s (20/59) fitted to handle deployment tanking,
if wing drogues are even necessary for that (although it's certainly safer from
a redundancy standpoint). If we really need them we could always fit 10-20
more, but I suspect the main need for wing drogues is in tactical tanking, which
is where the KC-135s are better suited -- given their limited numbers we should
never use KC-10s for tactical tankers until every strategic and deployment
tanker mission is covered.
Guy