Evening star., 1935-05-23
NEW Wind TUNNEL.
TESTS PLANE SPIN
Aviation Leaders Inspect
!. Device That Eliminates
, Test Flight Needs.
BY JOSEPH S. EDGERTON,
stan Correspondent Of The Star.

Va. May 23.-One of the most diff
cult and dangerous phases OF aero
nautical test work, the spinning OF
new airplanes to determine their
safety characteristics, now can be &C
complished in the comfort and Sc
curity of the laboratory with abso-
lutte safety to all concerned, 1t has
been demonstrated here to the largest
gathering of the Nations aeronautical
leaders ever to attend the Annual
Engineering Conference of the Ma
tional Advisory Committee for Aero
nautics.
The new free-Spinning wind tun-
mel, in which every phase OF an air
plane spin may be studied with mi
croscopic exactness for the first time,
was the most important Of the new
pieces of scientific equipment at the
Langley Memorial Laboratory dem
onstrated yesterday and today as the
representatives of the industry
gathered to witness the results OF a
year of progress and map a program
for the coming year.
In the new tunnel scale models OF
any airplane may be put into the So
called tail spin" or the even more
dangerous fat spin and the controls
automatically operated In an eHort
to break the spin.
Test Pilot Commends 1t.
"WeI, that's what call real prog
ress," remarked Lee Gehlbach, noteo
test pilot, who few days ago mar
rowly escaped with his life when
new military airplane went into a
suin which he could not break. 1T S
a whole lot better to sit here in the
laboratory and watch the progress OF
a spin than to have to watch from
beneath a parachute an airplane
which you have had to leave spinning
down over your head. with the
ground rushing up at you, while you
wonder whether the airplane Is going
to land on you"
In the new tunnel, shown to the in
dustry for the first time, the Govern
ment's aeronautical scientists hope to
work out designs for airplanes which
will not possess dangerous spinning
characteristics. This item of research
Is regarded as one of the most i'm
portant and difficult of the subjects
concerned with the safety OF flight.
In the new tunnel, a rising vertical
let of air Is feet in diameter, subject
to close velocity control, is employed.
Models of the airplanes to be tested
are launched in a spinning attitude In
the let and the subsequent spin and
recovery or the resulting crash may
be observed at close range and re-
corded by motion pictures. BY means
of an automatic device incorporated
in the model, the control surfaces may
be operated in any manner and the
effect determined.
800 Examine Tunnel.
Though the tunnel Is new, 1t has
been in operation for a sufficient
length of time to determine that the
spinning of models Of standard air
plaines in the tunnel agrees remark
ably with that of the full size air
planes in the tunnel agrees remark
vided one of the highlights for more
than 300 of the Nations aviation lead
ers at the tenth annual engineering
conference yesterday. A majority OF
the party returned to Washington to-
day aboard the Norfolk and Washing
ton steamer. More than 100 repre-
sentatives of Army and Navy aviation
crowded out yesterday, are going
through the laboratories today.
Col. Charles A. Lindbergh flew to
the conference yesterday in his new
two-place cabin monoplane. His plane
was one of more than score OF all
types which brought representatives
of the industry from many States
Senator Pat McCarran of Nevada, q
member of the party from Washing
ton, made a hurried flight back to
Washington yesterday afternoon when
he received word the bonus vote was
due.
New Tunnel Being Built.
A new high velocity wind tunnel
IN which model airplanes may be sub
jected to velocities of up to 500 miles
per hour Is being constructed to fur
ther the designing of airplanes capa-
bic of speeds more than double those
of the transport airpIanes Of today.
When a transport airplane flying
between Washington and Pittsburgh
recently snapped propeller, with re-
sulting vibration which tore wing
engine out of the ship. it demon
strated the danger of metallic fatigue
due to vibration and showed the ne
cesSity for vibration studies now being
conducted. In a new machine here
propellers may be vibrated until they
whip like willow wands. It has been
proved that propeller fractures al
ways occur at the nodes of vibration
and that by determining and
strengthening these points much may
be done to overcome failure Of the
metal. The demonstrations show that
the characteristic roaring of an air.
plane is due almost wholly to pro-
peller vibration, the propeller acting
precisely as does tuning fork.
New Landing Gear Shown.
Fixed landing gear creating only a
little more resistance than some Of
the new retractable types was shown
BY sinking rivet heads into "dimples'
IN sheet metal pontoons and floats
q IA per cent reduction in friction
may be obtained. 1t was shown that
by minor changes in design of engine
coWlings far better cooling and speed
may be obtained.
hlIlUllS UllOoC nt WIG SOAAASAIiAAS oAN
Col. Lindbergh, Maj. James H. Doc.
little, Maj. Afford J. Williams, Vincent
Bendix, Henry Berliner, DR.. Lyman
y. Briggs, DR.. Charles G. Abbot, Real
Admiral Mark L. Bristol, Rear Admira
Ernest j. King, Maj. Gen. Benjamin
D. Foulois, Brig. Gen. Frank M. An
drews, Brig. Gen. Henry Pratt, Eugene
l.. Vidal, Assistant Secretary OF Wal
woodring, Frank w. Caldwell, j. D
Condor, j. Carroll Cone, r. S. Damon
DR.. II. c. Dickinson, Comdr. Garland
Fulton, Lester D. Gardner, John H
Geisse, Charles P. Graddick, Willis
r. Gregg, Harry F. Guggenheim, Ed
ward P. Warner, Jerome c. Hunsaker
C. S. Casey" Jones, Temple N: Joyce
r. G. Kellett, Prof Alexander Klemin
Rear Admiral Emory S. Land, Charlie!
/. Lawrance, DR.. George w. Lewis
William P. MacCracken, jr.; Glenr
L.. Martin, Harold F. Pitchairn, Capt
GoIdan n Richa rdsOn ZellS SOucek