Memorandum presenting an altitude investigation to determine the basic mechanism by which J65-W-4 turbine rotor-blade failures were occurring in service. The engine was installed in an altitude test chamber and a series of controlled engine throttle bursts, with and without inlet-air distortion, over a range of altitudes, flight Mach numbers, and inlet-air temperatures. An examination of the data obtained during the investigation indicated that the danger of turbine failure could be eliminated without any appreciable sacrifice in engine acceleration time.

Report presenting a correlation of combustion-efficiency data obtained in experimental investigations with 14 aircraft gas-turbine combustors. The precision is not good for some combustors, but can help in predicting the efficiency at different operating conditions and in comparing the performance of different combustors from data obtained in unrelated tests.

Report presenting an investigation of the cooling effectiveness of water films on the inner surface of a well-insulated, 4-inch-diameter duct with air flowing through the duct at a range of temperature and Reynolds numbers. Results regarding the effect of the gas temperature and mass velocity on liquid-cooled length, effect of coolant flow on liquid-cooled length, and some suggestions for further investigation are provided. Equations for correlation are created from the data.

Results of wind-tunnel tests of a semispan model of a triangular wing of aspect ratio 2 with a skewed wing-tip flap are presented. Lift, drag, pitching-moment, and hinge-moment data are included for subsonic Mach numbers up to 0.95. The flap showed extremely high hinge moments and low effectiveness as a longitudinal control. Although less affected by compressibility, this flap is indicated to be inferior to a constant-chord flap when applied to this triangular wing.

From Introduction: "Performance data are presented in this report to show the characteristics of the turbine operating as an integral part of the engine. Typical results are graphically presented to show the effects of changes in altitude, flight Mach number, and exhaust-nozzle-outlet area on turbine performance. All turbine-performance data obtained are given in tabular form."

Report presenting a semispan triangular wing with a constant-chord trailing-edge flap to evaluate the aerodynamic characteristics of the wing with landing speeds up to a Mach number of 0.95. Tests were included to ascertain the effects of the addition of a body and of modifications to the airfoil section. Results regarding the wing alone with low Mach number, wing alone with high Mach number, effect of the body, effect of the flap, effect of Mach number, lift-drag ratio, and wing-profile modifications are provided.

Report presenting a flight investigation of an NACA hinge-moment roll research model with a sharp-nosed cylindrical body with a cruciform arrangement of 60 degree sweptback delta wings, two of which had half-delta tip controls. Data presented includes the variation with mach number of damping-in-roll coefficient, aileron rolling-moment coefficient, lateral-control effectiveness, and hinge-moment coefficient at various deflections. The rolling effectiveness of this configuration was found to be very satisfactory for a range of speeds.

Report discussing an investigation of the flight qualities of the Bell P-39D-1 airplane. Information about the longitudinal stability and control characteristics, lateral and directional stability and control, stalling characteristics, and control friction is provided.