Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-01-06

OraCOrleS or the world. Inc Ma
tional Advisory committee for
Aeronautics, at its Langley Field
laboratories, has devised a cowl-
ing for radial air-cooled motors
which has materially cut down air
resistance, increasing the speed Of
the plane and decreasing its fuel
consumption. It has conducted
tests to determine the precise
amount of air resistance created
by exposed objects, such as nuts
and bolts, cowl fittings, step plates,
wire and strut fittings and other
irregularities, and has determined
that Streamlining or burying of
these projects in the fuSelage and
wings results in considerable de-
crease in drag.
Landing Gear Problem.
The air resistance of the land
ing gear, including wheels, struts,
shock abSorberS and brakes, is one
of the most serious single prob
lens the aerodynamic engineer
faces. In some airplane models,
the landing gear causes as much
as 30 per cent of the air resist
ance, wind tunnel tests have re-
vealed.
Efforts have been made to de-
wise a retractable landing gear
which will fold up out of the way
into the fuSelage or wings. The
folding wheel landing gear is a
necessity in the amphibian plane
and high degree of success has
been attained. The new high
speed 20-paSSenger Burnelli COM
mercial monoplane, now ready for
it's test flights at the Newark, N. j.,
airport, is the first large land
plane to be equipped with retract-
able landing gear, the wheels fold
ing up into the bottom of the
fuSelage. This plane is interest
ing in other respects. The fuSelage
is remarkable for its width, the
cabin being IL feet wide. The
fuSelage, so far as can be de-
termined by examination of
photographs, is built like a huge
wing section which should, to
certain extent. tend to support
it's own weight in the air. The
twin motors are mounted side by
side in the nose of the fuSelage,
driving two propellers. Each motor
is in closed compartment and
is accessible to mechanics from
within the airplane, making pos
Sible minor repairs in flight. Owing
to the aerodynamic cleannesS of
its design, thiS plane, with full
load, is expected to have a cruiS-
ing speed of $50 miles per hour
and a maximum speed of ITS
miles.
Flying Wing Observed.
Other engineers are experiment.
ing with airplane designs il which
the fuselage is withdrawn par
TALLY or entirely into the wings,
leaving nothing but a flying wing.
England has witnessed the de-
velopment of Capt. G. T. r. Hills
weird Pterodactyl, which aban-
donS the conventional tail assem-
bly, and relies on wing-tip control,
more nearly approaching the Ely
ing wing" than anything recently
developed.
The problem of propeller loca-
ton also is causing the designer
much concern. Undoubtedly, for
aerodynamic efficiency, the motor
should be incloSed within the
wing. It is we'll known, however,
that the slip stream of a propeller
mounted in front of a wing de-
stroyS the lifting power of the Sec
ton behind. For this reason, some
European designers, especially
Dornier, have placed their motors
and propellerS on trestleS above
the wing, on the theory that the
greater wing efficiency so obtained
would more than counteract the
drag of the exposed trestle and
motor. Other designers are plac-
ing the propeller behind the wings,
using the "puSher" type of pro-
peller employed in the first air.
plane.
Future development probably
will be largely a matter of COM
promise and it is not unlikely that
the next few years may bring
forth airplanes embodying novel
and striking arrangements of
their various component parts.