Fw: B24 vs. B26: Which was more dangerous?
Lawrence Dillard
> news:avd42k$no4$1...@nntp3.u.washington.edu...
> To their crews, I mean. I've heard bad things about both, such them both
> being difficult to control.
By apparently a large margin, the B-26 was the more dangerous to the crews
of the two a/c.
The B-26 had been ordered into serial production on an emergency basis,
even before the prototype flew. It was a situation involving "invent on
cue" in
several cases. One serious flaw was that the low-drag wing was mounted at
an angle of incidence such that it was stalled out during its takeoff run,
necessitating that the a/c be deliberately rotated on takeoff. This flaw
went uncorrected until delayed wind-tunnel testing was conducted as part of
an investigation into the high number of accidents in which the a/c was
otherwise inexplicably involved.
Another flaw involved quality-control of the early versions of the
propeller control apparatus. As installed, the propellers would often "run
away"
during the initial climb-out, to very high rpms, a situation over which the
pilot could not exert control. Very often, this occurred on
takeoff/climb-out; the result was almost always a rapid roll which could
not be countered except by capable, alert pilots. But brand-new pilots (who
constituted the majority at the time) often crashed under such emergent
circumstances. In the early stages of the a/c's introduction into service,
relatively few experienced pilots who'd managed emergency circumstances in
earlier stages of their flight experience, were assigned to the a/c. (One
exception was a group composed of experienced bomber pilots, who took their
a/c to the Pacific and, operated them under austere conditions without
reporting unusual problems.)
The B-26 had tricycle gear, still unusual for a bomber at the time, and
high stall and landing speeds, a function partially of its small wing-span
and
large wing-loading. Once the a/c stalled, swift recognition and swift
corrective procedures were necessary if the a/c were to survive. Some
believed that the a/c simply couldn't be flown when necessary on one engine
alone.
At one point a Congressional investigation was instigated in response to
the large number of fatal accidents having occurred (the a/c had been given
certain nicknames indicative of its fatal crash record, e.g., "The Flying
Prostitute" (No visible means of support) and "The Widow Maker", and a
catch-phrase had become associated with it: "One a day in Tampa Bay" (a
major training facility was located near that Florida town). Col James
Doolittle was assigned by the USAAF to conduct trials on the B-26 in order
to help decide whether the program should proceed further or be cancelled.
Doolittle's test flights convinced him that the a/c was worth saving, flaws
and all.
His suggestions as to modified procedures were adopted, training was
altered, and better materials in and quality checks on the propeller
actuation system were instituted. Furthermore, after wind-tunnel testing, a
longer wing mounted at a greater angle of incidence was designed for and
fitted to later versions of the a/c. In the meantime, Doolittle (a competent
test
pilot and former stunt flier) gave several demonstrations during which he
showed that the a/c could fly quite well on a single engine, rolling it into
a feathered engine, landing with one feathered, etc., and showing that it
could be managed in an emergency if only the pilot knew what to do and
reacted accordingly.
Hence, only by the time the a/c was ready for large-scale commitment, had
its propeller management been rationalized, its wingspan lengthened and its
pilot-training revolutionized.
Lawrence Dillard
fitted to later versions of the a/c. In the meantime, Doolittle (a test
pilot and former stunt flier) gave several demonstrations during which he
showed that the a/c could fly quite well on a single engine, rolling it into
a feathered engine, landing with one feathered, etc., and showing that it
could be managed in an emergency if only the pilot knew what to do and
reacted accordingly.
Hence, only by the time the a/c was ready for large-scale commitment, had
its propeller management been rationalized, its wingspan lengthened and its
pilot-training revolutionized.
--
Mac
> > "James Anatidae" <pars...@citcom.net> wrote in message
> > news:avd42k$no4$1...@nntp3.u.washington.edu...
> > To their crews, I mean. I've heard bad things about both, such them both
> > being difficult to control.
> By apparently a large margin, the B-26 was the more dangerous to the crews
> an angle of incidence such that it was stalled out during its takeoff run,
> necessitating that the a/c be deliberately rotated on takeoff. <<
early cadet training, or even the early training in the Randolph Field
Central Instructors' School didn't have much in the curriculae about
the aerodynamics of flight. Actually, the finer points hadn't yet
been elucidated. Many instructors thought and taught that an a/c was
steered with the rudder, just like a boat. This concept was corrected
so that, by mid '42, the instructors were getting the 'true-word'
about a rudder being only a trimming device to counteract down-aileron
drag.
To say that an a/c wing is 'stalled' during a takeoff run reveals
absolute ignorance and destroys the reference's credibility. On
average, an airfoil stalls at about 20 degrees angle of attack, even
at higher than cruise speed. {High speed stall.} With a trigear, it
would be possible to have a negative angle of incidence {wing to
fuselage} such that the angle of attack {wing to airflow} would be
negative, not producing lift, and need to be rotated to some degree to
gain a positive angle of attack, therefore lift. The training a/c,
being taildraggers, until the B-25 became a twin-engine advanced
trainer, had a positive angle of attack at rest, while taxiing and on
takeoff run. One could take off from the three point position or raise
the tail to reduce drag and increase acceleration and then rotate for
lift off. As there were different ways to land, there were different
ways to take off. Much depended on the field surface and length. For
example: there were short field, soggy surface and hard surface
techniques.
The main problem, for the AAC, was the need to get as many men driving
a/c in as short a time as possible, so training time was significantly
reduced several times. Pilots and other airmen were expendable and
weren't expected to survive long in combat. Therefore, theory of
flight training and total flying experience was inadequate for all
situations in all a/c. The average graduate pilots of WWII were no
better at flying than the average licensed American automobile drivers
are today at driving. The latter wouldn't do well in any racing car of
today or in an 18 wheeler on the highway. In other words, the crews
were a bigger danger to themselves than were their vehicles. Not
pleasant to consider but that's the way it was. There were mechanical
problems and maintenance crew problems, but these were found with many
a/c, both fighters and bombers, including the P-51, B-17 and
Lancaster. Nothing is perfect, but a Japanese or German built
automobile comes close today and drove Detroit to higher standards of
precision and quality control when they were first imported in volume
some years ago. Note the Rolls Royce is now produced by a German
Corporation. Things do change with time, the economy and competition.
In general, the USAF now has better and older pilots. Mac.
--
ArtKramr
>From: "Lawrence Dillard"
>Hence, only by the time the a/c was ready for large-scale commitment, had
>its propeller management been rationalized, its wingspan lengthened and its
>pilot-training revolutionized.
That is rarther an overstatement of the facts. All that happenned was that in
every air cadet class, the top students were all sent to Marauders. These were
the men with the highest aptitide and the greatest talent as pilots. Lower
scoring students were sent to other aircaft assighnments I graduated 2nd in
my class at Big Springs and I plus the top 10% of rhe class were all sent to
B-26's. In additiion greater emphasis was placed on B-26 handling in
multi-engine transition. Hardly revolutionary.
Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer
Lawrence Dillard
news:b01i9c$20oi$1...@nntp6.u.washington.edu...
> "Lawrence Dillard" <lawr...@gbronline.com> wrote in message
news:<3e2b3b7...@news.pacific.net.au>...
> > > "James Anatidae" <pars...@citcom.net> wrote in message
> > > news:avd42k$no4$1...@nntp3.u.washington.edu...
> > > To their crews, I mean. I've heard bad things about both, such them
both
> > > being difficult to control.
> SNIP
>...One serious flaw was that the low-drag wing was mounted at
> > an angle of incidence such that it was stalled out during its takeoff
run,
> > necessitating that the a/c be deliberately rotated on takeoff.
> The above 'stalled out' statement is incorrect and misleading.
Not according to the US Army Air Corps, which commissioned a study into the
design of the B-26's wing by a highly-regarded airframe manufacturer.
SNIP (material dealing with training concepts)
> To say that an a/c wing is 'stalled' during a takeoff run reveals
> absolute ignorance and destroys the reference's credibility.
In that case, then Boeing Aircraft, then involved in building B-17s and
B-29s for the government, was absolutely ignorant and had no credibility,
because it was that organization which, at government behest, examined the
B-26's wing. Boeing's examination resulted in the conclusion I related in my
earlier post.
Boeing was faced with a similar rushed development situation in regard to
rapidly bringing a radical new aircraft into production, in its case the
B-29. One conumdrum it faced was how to achieve adequate lift for a very
heavy bomber a/c while using a small-area, low drag wing to allow for high
cruise speed flight. Somewhat like Martin Aircraft, Boeing came to be
inclined to use a wing of small area (given the projected weight of the
a/c), and to make use of advanced flap design to generate the necessary
lift for takeoff and drag for landing. In this process, Boeing examined many
designs, including the Davis airfoil and laminar flow sections (before
deciding to use one generated by their own design staff). Hence Boeing was
in a good position to evaluate the B-26s wing, and to do so in the least
possible time.
SNIP (discussion of airfoil angle of attack)
SNIP additional
In other words, the crews
> were a bigger danger to themselves than were their vehicles. Not
> pleasant to consider but that's the way it was. There were mechanical
> problems and maintenance crew problems, but these were found with many
> a/c, both fighters and bombers, including the P-51, B-17 and
> Lancaster.
I dunno. When a pilot with relatively few hours is assigned to fly a line
aircraft, I believe that the a/c should at least pose as few dangers to him
as possible during his initiation to it and during his basic and advanced
training on it. With the B-26, as I related in my earlier post, new pilots
were subjected to an a/c whose basic mechanical reliability (propellor pitch
mechanism) could quickly and insensibly place him--and his crew--into
coffins. The slogan "One a day in Tampa Bay" was hardly an exaggeration; the
a/c in question generally "landed" in Tampa Bay during the process of
taking off.
Indeed, training and operational accidents do happen. But in the majority of
the B-26 incidents, the pilot simply could not control the a/c due to
problems with lost engines, resulting primarily from defective propellor
control mechanisms (runaways).
Furthermore, the takeoff run for the earliest B-26s was longer than its
pilots could expect in advance, because of the (untaught) necessity for
positive rotation, which in turn was caused, Boeing concluded, by its wing
being in stalled condition during the takeoff run, not producing lift until
the tail was positively rotated.
Boeing's observations, as well as Col Doolittle's testing, led to the
redesign of the wing, including a longer span, and an improved angle of
attachment incidence, making takeoffs a wee bit easier on the pilot and
improving overall handling, and to major improvements in the propellor
control mechanism. Without these steps being taken (and, as Mr Kramer
pointed out in a recent post, assignment of only the most promising new
trainees to the a/c), the B-26 was an unreasonable danger to its crew and
the program otherwise faced immediate cancellation.
SNIP
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