Evening star., 1936-04-26
ANUFACTURERS ANSWER -: AVIATION NEWS

in the Naval Reserve Continuation
Of these inspection trips. 1t was ex-
plaired. should result ultimately in q
favorable and much desired UNDER
standing of the Aviation Reserve as q
whole"
MANUFACTURERS of American
radial air-cooled aircraft engines
finally have attained the long g-sought
goal of 1000 horsepower Two types
of engines, the Pratt g. Whitney Twin
Wasp and the Wright Twin Cyclone,
both have been given Department Of
Commerce approved type certificates
covering a rating of 1000 horsepower
maximum for take off purposes. For
ordinary operation, however, one of
the engines is rated at 900 horsepower
and the other at $50 horsepower.
Both engines are the most powerful
yet designed in the United States for
commercial airline use, although more
powerful fiuid-cooled engines, not
always successful, have been produced
for racing planes.
The big Wasp is rated by the De-
partment of Commerce, on the basis
OF gruelling tests, at 900 horsepower
at 2,450 revolutions per minute at $500
feet pressure altitude. This IS the
maximum horsepower for which the
engine is rated except for offs.
The maximum available, for one
minute, for take-offs is 1000 horse
power at $3.50 revolutions, with a full
rich" fuel mixture, employing 81 oc-
tame gasoline and with the engine su-
percharged to the equivalent of Alb
inches of mercury.
Although the 1,000-horsepower rat
ing is the extreme figure allowed by
the Department of Commerce, it is
claimed by the manufacturers that
the engine is capable of delivering
1,150 horsepower 1t is not unusual,
it was pointed out, for manufacturers
to ask for Department of Commerce
rating lower than the maximum power
claimed for the engine, a conservative
policy, which allows an extra margin
for extraordinary performance.
The Cyclone engine also is rated at
1000 horsepower for one minute at
1900 revolutions per minute at
Supercharger pressure equivalent to
40 inches of mercury. The degree Of
supercharging is evident when 1t is
compared with the normal atmos-
pheric pressure in Washington of
about 80 inches of mercury. The de-
gree Of supercharging in these en-
gines, therefore, runs 80 per cent
and greater above the normal atmos-
pheric pressure, for take-off maximum.
United Air Lines has Just placed an
order for IS of the new Twin Wasp
engines, which will power 10 Of the
giant new Douglas DC-3 transport
airplanes and provide reserve of six
engines. Other lines and the mill
tary services also have new engines
of both types and they soon will be in
the category of standard equipment.
nECLAR1NG that the military avia-
ton reserve of the United States
now has neither sufficient equipment
nor funds to operate efficiently" the
Joint Committee on Air Defense is
advocating:
I'D A reasonable number Of service
type planes; (2) reasonable number
of flying hours year; 81 pay for Re-
serve airmen who perform prescribed
training flights: "a indemnity and
disqualification for Reserve flyers or
their dependents for injuries sus-
tanned in training flights commen-
surate with that allowed flyers Of the
Regular Air Corps or their depend
ents; 81 the administration Of the
Air Reserve establishment by quail
fed personnel. who recognize that In
time of war the Air Reserve must con-
stitute the Nations first line Of de-
fense in the air.
The committee pointed out that
the General Headquarters Air Force,
which was year old on March l.
lis still woefully short of personnel
and equipment" Recalling that the
Baker board recommended 1000 mod
ern combat airplanes for the General
Headquarters Air Force. the commit
tee quoted Maj. Gen. Frank M. An
drews, commanding general of the
force:
In our recent maneuvers in Florida
the whole available strength Of the
General Headquarters Air Force in
modern aircraft was assembled. 1t
totaled only 145 airplanes. We are
short equipment. personnel and bases.
Due to age and wear and tear on
equipment. the General Headquarters
Air Force has lost in numerical
strength of airplanes since its or.
ganization. until now it is below the
strength with which it started"