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In article ain>, borf@ponus.org writes
>Hmm... If I recall correctly, the assumption that spins were fatal was
>held until the later part of WWI. An individual (whose name escapes me,
>but who went on to become very famous in Britains air doings, through
>WWII) proposed that recovery from a stall was possible. He became a pilot
>in part to test his hypothesis, and did successfully prove it to be the
>case. It then was used as a tactic to escape from German fighters, as the
>Germans just assumed that the plane was done for, but then would pull out
>of a spin many ks feet down and cruise away. The Germans also discovered
>spin recovery by the end of WWI.
I quote from that highly useful font of knowledge at
http://www.whittsflying.com/
(Article entitled Spins, spins, spins)
Lindemann
SPINS WERE A ONE TIME THING IN 1914
An unheralded aviation pioneer is British scientist, F. A. Lindemann.
"The Prof", as he was known, led a very checkered scientific and social
career from early WWI through WWII. He was an "idea man" and advisor to
Churchill for thirty years. He was a social butterfly and a scientific
gadfly to more capable scientists. However, his place in history could
well lie in aviation. You never heard of him?
Born of German/American parents, he spoke heavily accented mumbled
English. He knew all the "right" British nobility and used their
influence to gain both position and prestige. In 1914 he attempted, but
failed because of eyesight, to join the Royal Flying Corps. He then used
influence to join the scientific staff of the Royal Aircraft Factory.
Lindemann initiated a study of the instrument readings and pilot
procedures that seemed to cause the stall/spins occurring during turns.
A letter to his father stated, "Nobody can make out quite what
happened." Lindemann could find no apparent pattern as to when a stall
or a resulting spin might occur. Once an aircraft was in a spin there
was no way out of it. The spin turns would increase in speed until the
ultimate crash. All flight instructors warned, "Get into a spin; get
killed".
The "spin" was the most dreaded unintentional flight occurrence, which
resulted in accidents. More to be feared than the more frequent landing
accidents. At least, landing accidents could be explained. Lindemann now
had an explanation, a theory, about spins.
While never publishing his study results, Lindemann gave many oral
accounts of his findings. The spin frequently occurred when the aircraft
stalled in other than an absolutely level condition. If one wing dropped
any effort to raise it would cause the other wing to flip over the other
direction uncontrollably. Even at high speeds, a tight turn might cause
one wing to flip over and cause a spin. He insisted that further study
to prove the theory required that scientists fly.
Without any flight skills, Lindemann had worked out in theory the
probable forces, which caused and existed in a spin. He also figured
out, in theory, the control movements required to counteract these
forces. His study showed that any instinctive response would not work.
The rudder must be held fully against the spin while the nose was kept
pointed toward the ground. You could not pull back on the stick until
the spin stopped and flying speed was gained. His theory also seemed to
indicate that during the recovery the wings of the plane could be pulled
off. The way Lindemann used to test his theories was somewhat akin to a
medical researcher doing a self-inoculation for a deadly disease. He
worked through and around the bureaucracy, used influence, memorized the
eye chart for his "blind" eye and learned to fly "poorly". One flight of
uncertain date in 1914 justifies Lindemanns place in history.
On this Fall day, he discussed his theories on spin recovery and the
planned experiment with selected observers at Farnborough aerodrome. He
told them he would deliberately do a stall spin. He certainly must have
said his good-byes. He would be using a B.E.2 aircraft of most uncertain
flight characteristics. He departed and climbed for many minutes. Far
below, the observers saw him reach what must have been the B.E 2s
service ceiling of 14,000 feet. They saw the spin well before they heard
the cessation of engine noise.
Lindemann now began to test his theory. He pulled the power, slowed the
plane and entered into a stall. He held the stall until the left wing
dipped and the right wing flipped up for the spin entry. A deliberate
entry into a maneuver from which no one had previously recovered and few
had survived. A maximum test of accountability and courage.
The fragile airframe was held together by a maze of wires and struts
that maximized a power off vertical speed of about 90 mph. Lindemann
held the spin, intentionally or otherwise, until it was fully
established and then he initiated his unique recovery. A planned
application of control forces never before applied. He put in full
opposite rudder. Nothing happened. He waited. Still nothing happened. He
applied forward control pressure.
He had already fallen thousands of feet with no control effect
discernible. Was his theory going to fail at this critical moment? But
the rudder was starting to have an effect. The spin was slowing and
finally stopped. From the vertical, but without the spin Lindemann now
had to complete a recovery. Survival demanded that the pull out would
not remove the wings from the fuselage. Slowly, carefully the nose rose
and as it rose the aircraft slowed thus easing the stress on its
components. The first intentional spin and recovery. All that and
survival. Enough?
One such experiment and proof would have satisfied most people, but not
Lindemann. He climbed back up to altitude and did the spin and recovery
in the other direction. A theory twice applied and proven to be a life
saver. From that day on, a pilots education has not been deemed
complete without spin training. (Except, of course, in the U.S. by the
FAA)
The British had a military secret. It combined two of the very best
qualities of military combat. Deception and kill. Imagine their chagrin
when the British plane would level out close to the ground and scoot to
safety. Indeed, the spin was often used in WWI as a deliberate escape
maneuver. It wasnt long before the Germans discovered the deception and
began to follow spinning planes all the way to the ground. It is not
known how the Germans gained the secret of spin recovery. Pilots like to
talk flying with other pilots.
Most great aircraft flights recorded in aviation history are about
distances, speeds and kills. Why not a special "save" category for
Lindemann along with Immelman? But again, wouldnt your entering his
name into your memory and applying his theory and practice to your own
"Lindemann" spin recovery be sufficient.
There are masses of other useful information available (of immense use
for this fledgling pilot!).
--
John Gruson - 13.6hrs
john@jgruson.demon.co.uk
http://www.jgruson.demon.co.uk/aviation.htm
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