Flight and ground investigations have been made to compare an exhaust-ejector installation with a standard exhaust-collector-ring installation on air-cooled aircraft engines in a twin-engine airplane. The ground investigation allowed that, whereas the standard engine would have overheated above 600 horsepower, the engine with exhaust ejectors cooled at take-off operating conditions at zero ram. The exhaust ejectors provided as much cooling with cowl flaps closed as the conventional cowl flaps induced when full open at low airspeeds. The propulsive thrust of the exhaust-ejector installation was calculated to be slightly less than the thrust of the collector-ring-installation.

Report presenting the results of flight testing to determine the zero-lift drag of an NACA 65-009 airfoil at a specified aspect ratio. The results are compared to previous testing of unswept and swept-back arrangements. The swept-forward and swept-back airfoils were found to produce lower values of zero-drag lift than the unswept airfoil.

Report presenting tests to determine the effects of sweepback angle and aspect ratio on the drag of an NACA 65-009 airfoil at supersonic speeds. The results indicated that for the range of Mach numbers investigated, increasing the sweepback angle and decreasing the aspect ratio reduced the value of the wing drag coefficient.

Report discussing an investigation to determine the effects of changes in aspect ratio and tail height on the longitudinal stability characteristics of a model with a 32.6-degree sweptback wing. The effects of a leading-edge discontinuity were also examined.

The variation of dielectric constant has been measured as a function of the concentration of magnesium particles; the shape, size, and degree of oxidation of the particles; the temperature; and the frequency of oscillation. The variation of dielectric constant and settling rate was investigated as a function of time. Also investigated were the effects of particle concentration, shape and time on dielectric losses.

Report presenting tests to determine the flight characteristics of an F-86A airplane equipped with an area-suction boundary-layer-control system on the flaps and to investigate the possible operational problems which may arise on a flight installation of boundary-layer control. Results regarding the airplane with slatted leading edge, suction requirements, airplane with suction flap and various leading-edge configurations, factors affecting flap lift increment, and operational characteristics of boundary-layer control are provided.

Report presenting flight measurements on a swept-wing jet aircraft to determine the effects of adding forward camber and an increased leading-edge radius on the low-speed stalling characteristics, the high-speed static longitudinal stability, and the airplane drag. The modified leading edge produced values of maximum lift somewhat greater than the slats on a normal airplane, but the stall was unacceptable because of an abrupt roll-off.

Report presenting information regarding transient oscillations observed in response to elevator pulses of the Douglas D-558-I airplane at a range of Mach numbers and altitudes. An application of the Fourier transform was used to obtain the frequency-response characteristics. The effects of lift coefficient on the frequency response are also included.

Report discussing testing of a Douglas D-558-II to investigate its longitudinal stability characteristics in accelerated flight at supersonic speeds. Information about the normal-force coefficients and their relation to stability and pitch-up of the aircraft is included.

"Results are presented of a free-flight investigation between Mach numbers of 0.7 to 1.3 and Reynolds numbers of 3.1 x 10(exp 6) to 7.0 x 10(exp 6) to determine the longitudinal aerodynamic characteristics of the Northrop MX-775A missile. This missile has a wing, body, and vertical tail, but has no horizontal tail. The basic wing plan form has an aspect ratio of 5.5, 45 deg of sweepback of the 0.406 streamwise chord line, and a taper ratio of 0.4" (p. 1).

Memorandum presenting results of a free-flight investigation over a range of Mach and Reynolds numbers to determine the longitudinal aerodynamic characteristics of the Northrop MX-775A missile. The missile has a wing, body, and vertical tail, but has no horizontal tail. Results regarding basic data, drag, trim, lift and static stability, damping, and static pressure are provided.

Report presenting an investigation of an axial-flow compressor rotor with a 13-percent reduction in exit annulus in Freon-12 gas at a range of tip speeds. In order to analyze the results caused by the reduction, the performance of the rotor was compared to that of the same rotor with a constant annular area. Results regarding the overall performance, radial variation of performance, and blade-element performance are also provided.

Report presenting data obtained from an investigation of the Douglas-D558-II airplane to determine its buffeting characteristics at high lift and supersonic speeds. From Summary: "Buffeting was encountered at normal-force coefficients greater than about 0.7 in the Mach number range from 0.96 to 1.27 but at Mach number of 1.57, a peak normal-force coefficient of 0.80 was attained with no indication of buffeting. The increase in buffet intensity with lift is very gradual at supersonic speed compared with the buffet intensity-lift variation at subsonic Mach numbers."

Report presenting an experimental investigation of external airfoils, known as paddle-control surfaces, as the longitudinal control device on a triangular wing of aspect ratio 2. The lift, drag, pitching moment, and hinge moment were obtained for a variety of Mach numbers.

"The tests reported herein were made for the purpose of determining the high-speed load distribution on the wing of a 3/16 scale model of the Douglas XSB2D-1 airplane. Comparisons are made between the root bending moment and section torsional moment coefficients as obtained experimentally and derived analytically. The results show good correlation for the bending moment coefficients but considerable disagreement for the torsional moment coefficients, the measured moments being greater than the analytical moments. The effects of Mach number on both the bending moment and torsional moment coefficients were small" (p. 1).

Report presenting an investigation to determine the stability and control characteristics of a vertically rising airplane model. Results of preliminary hovering flight tests are made in still air, away from the interference effects of the ground and side walls, and with normal airplane-type controls operating in the slipstream.

Memorandum presenting an experimental investigation of four rectangular-throat two-dimensional wedge exhaust nozzles. Three of the nozzles were designed to conform to Prandtl-Meyer streamlines for pressure ratios of 5, 10, and 24, and a fourth, arbitrarily contoured, with a length less than that required for isentropic expansion, was designed for a pressure ratio of about 9.

Report presenting an investigation to determine the effect of several chord-extension configurations at low speed on a variable-sweep airplane model with a partially cambered wing. Testing occurred at a designated Reynolds number based on the mean aerodynamic chord of the wing at 50 degrees sweep for average test conditions. Results regarding the effect of chord extensions at 50 degrees, 60 degrees, and 20 degrees sweep, effect of chord extensions on lateral stability, and a comparison with different wing modifications are provided.

Memorandum presenting the results of flight testing of four different ski-equipped airplanes. Two types of skis were tested: hydro-skis designed to operate under or on the water surface and general-purpose skis designed to operate on a variety of surfaces but not underwater. A breakdown of the ski performance for each plane and ski combination is provided.

Report presenting an investigation of the effects of rocket-armament-exhaust-gas ingestion on the performance of a supersonic-inlet J34-turbojet-engine installation at Mach 2. Rockets were fired from two different spike positions and with the engine at high or low speed. Results regarding engine air flow, temperature, and flame-out are provided.

Report presenting an experimental investigation of a series of fixed-geometry exhaust nozzles which simulated a variable exit, which was conducted in the 8- by 6-foot supersonic wind tunnel at Mach numbers 0, 0.6, 1.5, 1.7, and 2.0. Gross thrust performance of the long-shroud exit configurations was considerably better than the short-shroud. Results regarding flow coefficients, thrust characteristics, flight performance analysis of data, and shroud drag are provided.

"An investigation was conducted to compare the knock-limited performance of a 20-percent triptane blend in 28-K fuel with that of 28-R and 33-R fuels at high engine speeds, cruising speeds, and two compression ratios in an K-1830-94 multicylinder engine. Data were obtained with the standard compression ratio of 6.7 and with a compression ratio of 3.0. The three fuels were investigated at engine speeds of 1800, 2250, 2600, and 2800 rpm at high and low blower ratios" (p. 1).

Report presenting an investigation of the flight characteristics of the Bell X-5 research airplane with sweepback that can be varied from 20 degrees to 59 degrees in flight. Lift and drag data have been obtained for the 59 degree sweep configuration for a range of Mach numbers and from zero to almost maximum lift.

"An investigation of the spin and recovery characteristics of a scale model of the Grumman XF9F-2 airplane has been conducted in the Langley 20-foot free-spinning tunnel. The effects of control settings and movements on the erect and inverted spin and recovery characteristics of the model in the flight loading were determined. The investigation also included spin-recovery-parachute, pilot-escape, and rudder-pedal- . force tests" (p. 1).