Evening star., 1935-07-07

New airplane records and efficiency
are promised by the development of
gasoline OF the highest anti-knock
quality yet produced. The new fuel.
yet too expensive for anything but ex-
perimental work, has l0O-octane
value on the anti-knock scale, as COM
pared with the 87-octane fuel which,
until this Spring, was the highest
quality used for commercial airline
operation, according TO DR.. Graham
Edgar, vice president and director of
research of one Of the large gasoline
companies.
DR.. Edgar, who devised the octane
number scale for registering the anti
knock qualities Of gasoline nine years
ago, said that modern aviation fuels
have improved beyond the point where
his scale is any longer a definite meas
uring rod for the new experimental
fuels. His scale takes as zero the
hydrocarbon hectane, which has a
greater tendency to produce knock in
internal compustion engines than any
commercial gasoline. Iso-octane, which
in 1926 had the highest anti-knock
quality known, was taken as 100 in
the scale. Anti-knock qualities of
gasoline are determined by mixing iso-
octane and heptane to duplicate the
specimen and s7-octane gasoline is
the equivalent of mixture of 81 per
cent iso-octane and 13 per cent hep
tame.
Experimental fuels now employ pure
iso-octane, further improved by addition
Of tetra-ethyl lead. which increases
the anti-knock quality of the fuel to
more than 100 and puts it out of the
range of present scales. Tests have
shown that the ad-treated iso-octane
is capable of developing at least "a
per cent more power than iso-octane
itself without causing engine knock.
The largest airliners now use 81
octane gasoline for take-offs and
emergencies, the planes carrying the
high-test fuel in separate tanks. Fuel
of 80-octane value is used for ordi-
nary cruising. Should one engine
stop, the S7-octane fuel is burned in
the other engine to provide increased
power.
When D. w. TomlinSon and Joe
Bartles established eight new world
records last month they used 90-octane
gasoline for taking of and 87-octane
for cruising. The result was that they
were able to take off with a fuel load
which exceeded by 1000 pounds the
normal maximum load of the airplane.
, With this tremendous overload they
took off after run of 81 seconds and
climbed to an altitude of 10000 feet
in 80 minutes on the 90-octane fuel,
switching then to the 87-octane for
the flight of more than 5000 miles.
DR.. Edgar believes that fuels Of 100
octane number and above will come
into commercial use in the not too
distant future and that when they
do great increases in airplane speed
and efficiency will result.
Sixty new Consolidated Ply patrol
airplanes for which contracts have
| just been awarded by the Navy De-
! partment will give the Navy its first
real trans-oceanic flying unit. AL
though squadron of the earlier P2Y
| patrol boats made the famous forma-
ton flight from California to Hawaii
last year, setting a new world non
! stop airline distance record for flying
boats, the Navy was not entirely salts
fed with the plane for long range
patrol work. They operated very close
to maximum performance limits on
that flight.
The new patrol planes will have
much greater speed and a far greater
| range than the model which made
history last year and will be far more
efficient for long distance ocean patrol
flying. They will weigh no more than
the earlier model, despite the greatly
improved performance.
The new patrol boats will be con-
structed at a cost of about $4,000
each and contracts for the planes and
their power plants, together with 20
per cent supply of spare parts for
airplanes and 25 per cent for engines,
total $8,507,037. The Navy Depart
ment has ordered $50 engines and $50
variable-controllable pitch propellers,
allowing 30 spares of each.
In view of the acrimonious fight
waged by congressional committees
against the negotiated" contract sys-
tenn of purchasing military airplanes,