The sun. [volume] (New York [N.Y.]) 1833-1916, 1914-07-19


of inherent stability Is being purposcly
cut down in order to gain in manuu-
wiring efficiency
The ideal air craft, then, should be
one of flexible control and yet suscep-
tible Of satisfactory stabilzing. Tho
Sperry gyroscopic apparatus has been
designed TO meet the latter desideratum
and has proved its capabilities.
An aviator must soon tire II he 70
operating In a gusty wind and seeks by
manual or bodily control to steady his
craft. At best, he Is conscious of the
need OF action only after his machine
has acquired considerable angle OF
lateral heel or horizontal inclination.
Could he but fee, the first efforts Of the
tipping force, he could, by a slight ad-
justment OF the proper planes, check
the rocking motion in It's very be-
ginning.
This is really the gift which the bird
possesses. especially the soaring birds.
which circle through the air much after
the fashion Of the mechanical fiier of
to-day. Nature has given them an ex-
quisite sense OF balance and they have
feeling to the uttermost tips of their
wings. The airman. on the other hand,
sits at the centre OF his craft; is ut the
point where there Is least motion; and
accordingly Is not aware of the need Of
corrective action until the aeroplane has
acquired n considerable degree OF an
gular motion.
Col. Eteve OF the French service
sought TO overcome this human short
coming by means OF a little apparatus
which would warn the aviator quickly
and indicate to him the compensating
mannuvre 10 be made. However, IL put
the burden Of safety ultimately upon
the pilot and in no way lessened the
nervous strain; indeed. the frequency
OF these mechanical cautionings were
enough, In themselves. to keep him in
state of exhausting suspense.
Elmer A. Sperry recognized about four
years ago that something must be done
to relieve the airman OF needless duties
in order that he might have more time
to navigate his machine and to be free
to take the observations demanded OF
a military pilot. Unquestionably Mr..
Sperrys aim was TO increase the value
of the flying machine as an instrument
of war. but what he has actually ac-
complished adds enormously 10 its po-
tential value as a commercial and sport
ing craft. From the beginning he be-
full basic element of control.
During the scores of flights in France
Lawrence Sperry subjected his auto
matically stabilized Curtiss biplane to
rigorous tests. While 600 feet up In
the air he got out of his seat, leaving
the steering wheel, and stood UP. After
taking this position his mechanic
crawled out on the wings laterally to a
distance of nearly seven feet. thus Great
ing an upsetting force which would
have meant sure death under ordinary
, circumstances. Nevertheless the hydro
aeroplane went smoothly on, controlling
itself the while, the stab!lizer shifting
the ailerons at the wing tips so as to
create a compensating pressure ut the
end Of the planes furthest from the VEN
turesome mechanic.
This deliberate disturbance was the
equivalent of tipping movement that
| might DO set up by n heavy sidewise
gust OF wind. 1t looked like spectac-
| ular display of nerve on the part OF
young Mr.. Sperry and his machinist, but
they had learned just how far they
could tax the stabilizer and ind II
equal to the demand.
Not content with this proof of lateral
stability, Lawrence Sperry again shifted
his own weight and his six feet of ath-
letic youthfulness by getting out of his
control seat and standing as before
thereby leaving the maneuvring OF the
machine to its own impulse. Next. the
mechanic crept back toward the tail, but
| in spite of that shift of weight the
hydroaeroplane kept its poise undis'
turbed, the longitudinal stabilizine
gyros manipulating the tail planes oil
elevators to the necessary degree. None
of the other competitors made any ef-
forts toward Stimulating these remark
able performances. and yet these ma
npuvres really were fairly tame beside
others which young Mr.. Sperry &C
complished.
In describing a circle or when making
any sharp turn in flight the aeroplane
heels over to a conspicuous degree JUS
as a soaring bird does. In aviation
parlance this is called banking. the aero