A lightweight instrument that utilizes resistance-wire electric strain gases to measure propeller-shaft thrust has been developed. A wind-tunnel investigation on a propeller installed, on a single-engine pursuit airplane showed that the instrument gave a reliable indication of propeller-shaft thrust to an accuracy of +/-2 percent within its calibrated range. No attempt was made to determine the relation of indicated shaft thrust to net propeller thrust.

Report presenting the specific impulse of liquid diborane and liquid oxygen over a range of mixture ratios in a 100-pound-thrust rocket engine operating at a combustion-chamber pressure of 300 pounds per square inch absolute. A faired curve through the experimental data had approximately the same shape as the theoretical curve.

In accordance with a request of the Bureau of Aeronautics, Navy Department, tests were performed in the Langley 20-foot free-spinning tunnel to determine the spin and recovery characteristics of a 1/24 scale model of the Grumman XTB3F-1 airplane. The airplane is a two-place, midwing torpedo bomber equipped with a tractor propeller and an auxiliary jet engine. The effect of control setting and movement on the erect and inverted spin and recovery characteristics of the model were determined for the normal loading.