Memorandum presenting a brief summary of the recent theoretical and experimental work on local heat-transfer rates on blunt-nose bodies. Results regarding the calculation of local flow conditions, prediction of stagnation-point heating rates, and calculation of heating rates over entire nose are provided.

Memorandum presenting a survey of the problems introduced by the increased longitudinal stability and reduced directional stability of aircraft operating in the low supersonic speed range. Information regarding longitudinal stability and directional stability are provided.

Report presenting the results of a wind-tunnel investigation of aileron flutter up to 0.822 Mach number. The testing indicated the absence of flutter of significant amplitude when a considerable amount of wing-tip relief existed and the presence of flutter when the relief was minimized. Results regarding the testing without the end plate, with end plate, and comparison with theory are provided.

The Mach number and temperature profiles in jets expanding from convergent and convergent-divergent nozzles are presented for several values of nozzle-exit pressure ratio. The effects of jet temperature, Reynolds number, and humidity on jet spreading are briefly evaluated. The results indicated that the downstream Mach number profiles for a heated jet are slightly narrower than those for a unheated jet, whereas the downstream temperature profiles were unaffected by nozzle temperature change, and that the effects of Reynolds number and humidity were negligible.

Report presenting a wind-tunnel investigation of two semispan wing models with 45 degrees of sweepback, an aspect ratio of 5, and a taper ratio of 0.565. One wing had no camber or twist while the other was cambered for a design lift coefficient of 0.4 and twisted to relieve loading at the tip. Results regarding the plane wing, cambered and twisted wing, wing-body combinations, effect of camber and twist, effect of fences, effect of surface roughness, and lift-drag ratio are provided.

"The frequency content of the control input and resulting airplane motions is presented as power spectral densities for one operational flight of the fighter airplane (Republic F-84G). The frequency content, which is described by the shape of the spectrum, may be useful in providing inputs for the design of power control systems. For normal load factors, the results presented for the operational flight considered are in general agreement with the results of more complete data on three fighter airplanes (Republic F-84G, Republic F-84F, and North American F-86A)" (p. 1).

The flow fields near a 45 degree swept-wing-fuselage combination at moderate angles of sideslip (plus-or-minus 8 degrees), as determined experimentally at low speed, are presented as variations with chordwise distance for various spanwise and vertical locations and angles of attack. The results indicated that for positions close to the fuselage (on and near the plane of symmetry) changes in the angle of sideslip caused large changes in the flow-field characteristics and particularly in the local angles of sideslip, which in some cases were nearly double the static angle of sideslip.

Memorandum presenting a survey of the problems introduced by the increased longitudinal stability and the reduced directional stability of aircraft operating in the low supersonic speed range. The longitudinal stability increases markedly at supersonic speeds and results in high drags due to trimming and in limited control for maneuvering. The vertical-tail contribution is shown to be affected by many factors including the wing position, the fuselage shape, and the horizontal-tail position.

"A series of calculations of the dynamic response of airplane wings to gusts were made with the purpose of showing the relative response of a reference airplane, the DC-3 airplane, and of newer types of airplanes represented by the DC-4, DC-6, and L-49 airplanes. Additional calculations were made for the DC-6 airplane to show the effects of speed and altitude. On the basis of the method of calculation used and the conditions selected for analysis, it is indicated that: 1) The newer airplanes show appreciably greater dynamic stress in gusts then does the reference airplane; 2) Increasing the forward speed or the operating altitude results in an increase of the dynamic stress ratio for the gust with a gradient distance of 10 chords" (p. 1).