Report discussing the effects of circular-arc spoilers on the section characteristics of an NACA 66,2-216 airfoil with a 0.25-chord slotted flap. Spoilers were tested on the upper surface of the airfoil, on the lower surface, and on both simultaneously. Only the simultaneous placement of spoilers was found to provide satisfactory results as a lateral control device.

Propellers with trailing-edge extensions were studied to determine aerodynamic characteristics. Trailing-edge extension increased power absorbed by propeller with little loss in efficiency. Power coefficient for maximum efficiency was greater for 20% camber type extension than for 20% straight type extension over range of advance ratio of 1.0 to 2.5 although camber type was less efficient. Efficiency was about the same for cruising and high-speed at a high power coefficient for propeller with extension.

Report discussing testing to determine the longitudinal stability and control and stalling characteristics of a DeHavilland Mosquito F-8. Special focus is given to the control forces, elevator control, trim changes, and stick fixed and stick free characteristics of the aircraft.

"The purpose of this report is to provide designers of airplanes with information that will be helpful in obtaining good ditching characteristics in new designs. The results from a number of model tests and report of actual ditchings are used as a basis for which to draw conclusions as to the effect on ditching performance of general arrangement, interior arrangement, fuselage shape, and other design parameters. The characteristics of several types of ditching aids that could be incorporated in a design are also discussed" (p. 1).

Report discussing flight tests on a low-drag wing pursuit airplane to determine the effects of Mach and Reynolds numbers on the maximum lift coefficient obtainable in gradual and abrupt stalls. The obtainable maximum lift coefficient was found to be greatly affected by the Mach and Reynolds numbers in gradual stall. In abrupt stalls, the maximum lift coefficient was affected by the Mach number, but not the Reynolds number.

Report presenting an analysis of cylinder-to-cylinder temperature and mixture distributions of four different aircraft engines to determine the possible economy of automatically supply water or additional fuel to only those cylinders having excessive temperatures. The cooling problem as distinguished from the fuel-knock problem was studied and an analysis limited to those cases in which additional cooling is ordinarily obtained by carburetor enrichment was made.

Report discusses the results of testing conducted to determine the performance of automatic, internal-coolant valves actuated by cylinder temperatures.The performance of the valves with respect to temperature sensitivity, rapidity of response, and hunting characteristics is described. The relative effects on cylinder performance obtained by internally supplying water and additional fuel were also examined.

Report discussing testing on a powered model of the Fleetwings XBTK-1 airplane in order to investigate the lateral stability characteristics. Information about the effective dihedral, directional stability, potential for rudder lock, results of rudder modification, rudder effectiveness, and aileron effectiveness is provided.

Report presenting climb and high-speed tests of a Hamilton Standard No. 6507A-2 three-blade propeller, which have been made to determine the effect of blade loading on propeller efficiency. The normal and military power climb efficiencies were found to be about equal at altitudes below 16,000 feet.

Report discussing the cooling characteristics of a modified 14-cylinder double-row radial air-cooled engine installed in a four-engine airplane at a pressure altitude of 7000 feet. Testing of the variable charge-air flow, variable cooling-air pressure drop, and variable fuel-air ratio was conducted. The cooling equation, temperature-limited performance, maximum engine temperatures, and other information predicted by calculations is described.