Fw-190 with Slipper Tanks
Rob Arndt
Better than drop tanks or severe combat liability?
Rob
The Enlightenment
"Rob Arndt" <teut...@aol.com> wrote in message
news:1104521479....@c13g2000cwb.googlegroups.com...
> http://modelingmadness.com/scotts/axis/luft/fw/190/190slipc.jpg
> Better than drop tanks or severe combat liability?
>
> Rob
>
Better than drop tanks. Slipper tanks effectively area rule the aircraft.
If properlly designed they can actually reduce drag of the aircraft.
You will find that Dr Küchemann who developed effectively what is an area
rule aircaft using the principle of flow matching known as the "Küchemann
coke Bottle" to Airmerican's going over Germnan research:
http://www.luft46.com/fw/fw1000a.html
Küchemann moved to the UK and eventually became a citizen there where he has
attributed to him the "Küchemann Carrots" that were added to the Handley
Page Victor crescent wing bomber. The weight and added wetted area
probably negates the effect however the fuel volume added justifies it. You
will also notice these 'carrots' used to stow rough field undercarriages in
Soviet Aircraft and on the Tu 95 Bear. In the Victor they were used as
chaff dispensors. Küchemann Carrots sometimes are known as Whitcombe Pods.
You will find that some variants of the two seat Me 262B2 jet night fighter
when with more powerfull HeS 011 engines were exepected to allow a range of
around 1500 miles when equiped with slipper tanks.
PS. Do you mind providing a link to an actual page rather than just an .jpg
image on your many posts. It is impossible sometimes find the hopmepage for
more info.
Rob Arndt
homepage. Sorry.
Rob
B2431
>Date: 12/31/2004 13:31 Central Standard Time
>Message-id: <1104521479....@c13g2000cwb.googlegroups.com>
>
>http://modelingmadness.com/scotts/axis/luft/fw/190/190slipc.jpg
>Better than drop tanks or severe combat liability?
>
>Rob
>
Fuel tanks? If they really are there will be a severe CG change as the fuel
moves fore and aft in climb and dive. All the slosh baffles in the world won't
change that.
Dan, U.S. Air Force, retired
Krztalizer
>Fuel tanks? If they really are there will be a severe CG change as the fuel
>moves fore and aft in climb and dive. All the slosh baffles in the world
>won't
>change that.
Hi, Dan. This arrangement was not intended for combat as I understand it but
more for relocation flights. No combat-unit-assigned FW 190 recieved this mod.
Given that most wartime LW aircraft were notoriously short legged, this
general arrangement was explored for several types of aircraft but none went
into service that I know of (means nothing of course). The alternative to
these pods were rigidly-towed winged aux tanks & bombs that were supposed to
towed behind the a/c (8-262, 8-177, several others), but in practice, these
were horrible to control and many were lost in testing.
Even worse in my view were the overwing pax pods designed to be bolted to the
top of a Ju 87s wings. I guess its about as safe as riding within the radio
compartment on an FW 190 - but if the guy from the "Stuka Girl" episode could
be motivated to do it, I suppose I would accept a ride in there if it meant I'd
be missing a long vacation beyond the Urals...
v/r
Gordon
<====(A+C====>
USN SAR
Its always better to lose -an- engine, not -the- engine.
The Enlightenment
I don't know if they were intended for dog fighting: probably free
night fighting, special long range missions, ferry flights etc. I have
no exact data of their impact on aircraft performance after they had
been drained only that the effect of drag should be minimal.
I think there would be a way around the tank sloshing and C/G issue you
have identified. First the tanks are fairly close to the centre of
gravity and aerodynamic center of the aircraft even if they are 'high'
rather than 'low'.
This is the engineering solution I would propose: Split the tanks
horizonatally with a dividing wall so that there is a top half and
bottom half of the tank. The top half of the tank would gravity feed
via a non return valve to the bottom half of the tank. In this way
only a maximum of half the fluid capacity of the tank would ever be
'sloshing about' as the bottom tank would always be completely full
untill the top tank had emptied fully into the bttom via the non return
valve. Therefore Another advantage of the high mounted tanks is that
they can gravity feed into the normal wing tanks. There would still be
a few baffles to damp the reduced sloshing about enough so that there
would not be the possibillity of any fast pilot coupled oscillations.
The English Electric Lightning carried its rather impressively large
and long 'drop tanks' well above its wings and apparently this was an
excellent aerodynamic solution. I suspect Lightning would have needed
to roll inverted to release them and I wonder if this was considered
for the FW 190 as well to clear the tailplanes.
I would not be the only time such a manouever would be considered
opperationally 'standard' for release of a load.
F-111's when delivering thermonuclear bombs (Mk 24 ?) during a terrain
following low level penetration were expected to pull up at a high
angle of about 30 degrees, roll over upside down and pull back towards
the ground as they ballistically tossed their nuclear weapon several
miles (about 6-8). I expect a rapid turn left or right to avoid the
blast. Its probbly a technique that would work with buddy laser
designation and GPS guided conventional weapons.
B2431
>Date: 1/7/2005 19:51 Central Standard Time
>Message-id: <1105149091.8...@c13g2000cwb.googlegroups.com>
>
>
>B2431 wrote:
>> >From: "Rob Arndt" teut...@aol.com
>> >Date: 12/31/2004 13:31 Central Standard Time
>> >Message-id: <1104521479....@c13g2000cwb.googlegroups.com>
>> >
>> >http://modelingmadness.com/scotts/axis/luft/fw/190/190slipc.jpg
>> >Better than drop tanks or severe combat liability?
>> >
>> >Rob
>> >
>>
>> Fuel tanks? If they really are there will be a severe CG change as
>the fuel
>> moves fore and aft in climb and dive. All the slosh baffles in the
>world won't
>> change that.
>>
>> Dan, U.S. Air Force, retired
>
>I don't know if they were intended for dog fighting: probably free
>night fighting, special long range missions, ferry flights etc. I have
>no exact data of their impact on aircraft performance after they had
>been drained only that the effect of drag should be minimal.
>
>I think there would be a way around the tank sloshing and C/G issue you
>have identified. First the tanks are fairly close to the centre of
>gravity and aerodynamic center of the aircraft even if they are 'high'
>rather than 'low'.
I was referring to fore and aft C.G. as I stated. Assuming the tail cone of the
tanks is wet and the aircraft pitches up for any reason such as climbout the
fuel in the tank would move aft. Baffling won't stop this. If both tanks are
half full you have moved a coupla hundred pounds back behind the C.G. which can
be guestimated to be 1/4 to 1/3 mean chord. I don't know how finicky the Fw
was about C.G. limits.
Alistair Gunn
> The English Electric Lightning carried its rather impressively large
> and long 'drop tanks' well above its wings and apparently this was an
> excellent aerodynamic solution.
Well, as long as you didn't want to exceed about Mach 1.1 I believe?
Also, when Lightnings where sitting on airfield alerts with the tanks
fitted they used to launch with the tanks empty and hit a tanker to fill
right up on the way to the target. Lauching with the tanks full didn't
make any difference to endurance as the extra weight meant spending
longer on reheat using up the extra fuel ...
> I suspect Lightning would have needed
> to roll inverted to release them and I wonder if this was considered
> for the FW 190 as well to clear the tailplanes.
Wheren't the overwing tanks only meant to be released in an emergency?
In any case, you wouldn't need much vertical seperation to ensure the
tanks came down well behind your Lightning -> it's not like there's much
for them to hit ...
--
These opinions might not even be mine ...
Let alone connected with my employer ...
Krztalizer
>to roll inverted to release them and I wonder if this was considered
>for the FW 190 as well to clear the tailplanes.
I've seen a video of a Lightning releasing its overwing tanks and they came
off upwards - at least in that one video. As for these slippers on the FW:
these were bolt-on kits, not droppable tanks? Been a while since I read the
article in Jet and Prop, but I don't recall them being considered "drop tanks"
even though that is how 'zusatzanken' (aux tanks) are usually translated.
v/r
Gordon
Ps, your solution to the sloshing certainly sounds feasible to me
Bill Shatzer
On 9 Jan 2005, Krztalizer wrote:
-snip-
> As for these slippers on the FW:
> these were bolt-on kits, not droppable tanks? Been a while since I read the
> article in Jet and Prop, but I don't recall them being considered "drop tanks"
Green ("Warplanes of the Third Reich") indicates the auxillary fuel tanks
-could- be jettisoned - or at least were intended to be jettisonable.
Apparently the installation was tested on only a single aircraft and
there's no indication about whether the testing ever actually reached
the stage of an actual attempted in-flight jettison.
> even though that is how 'zusatzanken' (aux tanks) are usually translated.
Green gives "Doppelreiter" as the German term for this particular
experimental auxillary tank installation.
Cheers and all,
Rob Arndt
which were intended for jet aircraft and were streamlined, upward
jettisonable.
Zusatzanken are literally translated as "Additive Tanks" and were
bolt-ons for the entire journey.
I'm so sick of people bringing up Green's book as some kind of
authority on German WW2 aircraft. Far from it. I can name hundreds of
mistakes in his book and lots of aircraft and "other" craft missing as
well.
Give it up already. That book is obsolete.
Rob
The Enlightenment
(i.e. slipper tanks) are intended to be jetisonable according to
"Green"
Not that I see how they would safely release these without danger to
the tail plane unless you roll inverted (this should be a basic
manouever for a fighter pilot but it would be a pain if you were
"jumped".
Many world war 2 books are incorrect in the details of German aircraft.
Performance specifications for a particular version are misapplied for
another version. For instance the Fw 190 A-9 is listed as not being
produced, or as having strengthened leading edges for ram attacks when
the aircaft was in fact produced in numbers of 900 or so. This
aircraft could apparently outrun a Mustang.
The other point is the listing of engine power and engine types.
Frequently there were many modifications such as rich mixture
injection, water methanol (both high and low pressure), improved
supercharger types, notrous oxide, (GM-1 became desirable when a Dr
Lutz discovered a way of making it 'bullet proof'.
Thus they would have a basic takeoff peformance, a special performance
overboost rich mixture which was not available in some cases below
about 5500 feet) and a special emergency performance (usually MW50).
I believe (yet to confirm) the DB605AB of the Me 109K-4 was eventually
cleared for 2000hp on 1.98 atm boost on C3 + MW50 and 1800 hp on 1.72
atm boost on B4 + MW50.
A German ps (pferde sterke or horse power) is 0.996 of a British or US
horsepower and in some cases the translation fails to make the
conversion.
Just trying to work out the facts on engines is a big matter.
Alistair Gunn
Who it this "Alister Gunn" character but it clearly isn't me! <grins>
> is suggesting that the "Dopplereiter"
> (i.e. slipper tanks) are intended to be jetisonable according to
> "Green"
In the event that you where referring to me, perhaps you should've read
to the end of my post where it clearly says "... came down well behind
your Lightning"?
old hoodoo
If Green only has "hundreds of errors" thats a tribute to his work
which encompasses a huge amount of information and was an attempt at a
centralized and concise work on Luftwaffe aircraft. It was a
breakthrouh work when written.
W of the 3rd Reich is a masterpiece when one takes into the account
the time period it was made. When you come out with something
comparable, let me know. While somewhat outdated on many details, it is
still a very valuable reference. If you consider it "obsolete" by your
standards, you have got a set of very discriminating standards that is
not discernable in the quality of your posts. Nowdays we have a lot
more references, but many of those prove to be of a secondary nature
and often heavily biased.
Your own posts seem to show a distinct preference and fascination
for anything "Kraut" (WWII Nazi era, that is) and if I think you were
to write a history you would give the Nazi regime credit for just about
every flight innovation ever used in an aircraft. Guess that is why you
use "teuton" in your handle.
You are denigrating a fine historian. Show a little respect.
Rob Arndt
reference book. I have it but never really used it very much back then.
I used "Hitler's Luftwaffe" and "History of the German Air Force" more.
Besides, with all the secret weapons books I had Green's book missed
the mark on many aircraft and weapon systems. I won't even get into the
disc aircraft either.
You say do I have something better? I do- my own book which is close to
200 pages by now and filled with 100s of photos and rare material not
found in any other book. I prototyped 3 advancing copies at Kinko's on
my own to get an idea how the book would look with high gloss paper and
a perfect bind with color covers in gloss paperback editions.
You know what? I got offers to sell the prototypes at the store! I went
to just my local model shop and my job and have over 100 orders already
once the book is copyrighted and hardcopied. In addition I am pursuing
a concept flag that will go with the book. Prototyping on that has
commenced as well.
So, while I respect Green his material IS outdated and my book is
absolutely unique with ALL known German disc projects, circular and
annular wing aircraft, spheres, and cylindrical craft that Green
doesn't have... nor Schiffer Books... nor Midland Books.
BTW, my site does not reflect the book as the owner has not posted the
updates deliberately to allow me to complete my finalized book texts.
The online site is also missing 100s of photos that I keep in a digital
album for my printing preferences and these can produce every kind of
merchandise available- T-shirts, mugs, mouse pads, calendar, etc...
I don't worry about Green and his book. I only stated that I was tired
of people bringing it up as a reference book. To me it is as worthless
as any Ian V. Hogg reference on German Secret Weapons.
Have fun on the NG while I work on my book and flag.
Rob