"This note describes tests of an adjustable blade metal model propeller, both in a free wind stream and in combination with a model fuselage, at four settings of the blades. The model propeller is designed for a uniform nominal pitch/diameter ratio of .7 and the blade settings used correspond to nominal pitch/diameter ratios of .5, .7, .9, and 1.1 at the .6 radius. The tests show that propellers of this type may be considerably changed in setting from the designed pitch angles and yet give excellent performance" (p. 1).

Discussed here are problems with the use of cowlings with radial air cooled engines. An XF7C-1 airplane, equipped with service cowling and with narrow ring, wide ring, and exhaust collector ring cowlings over the service cowling, was used. For these four cowling conditions, the rate of climb and high speed performance were determined, the cylinder conditions were measured, and pictures to show visibility were taken. The level flight performance obtained with an engine speed of 1900 r.p.m. for the service type, the narrow ring, the wide ring, and the exhaust collector ring was 144.4, 146.6, 152.8, and 155 mph, respectively.

Note presenting injection lags determined for a common-rail fuel injection system for a compression-ignition engine. The system consisted of a high-pressure reservoir, a timing valve, an injection valve tube, and an automatic injection valve. Results regarding the variable injection valve tube length, variable tube diameter, variable valve opening pressure, variable injection pressure, and variable initial pressure are provided.