Report discussing the creation of a thermal ice-prevention system of a bomber-type airplane to provide protection against ice and fog formations on the transparent fairing over the landing light in the wing leading edge. A comparison between the design performance and actual performance showed that the outer-surface heat-transfer coefficient was correctly predicted, but the inner-surface heat-transfer coefficient was four times as large, leading to failure of the plastic fairing.

"Pressure-distribution measurements were made at the request of the Materiel Division, U.S. Army Air Corps, on a 24-inch-chord wooden model equipped with a slotted flap and submitted by the Curtiss-Wright Corporation. The tests were made in the Langley two-dimensional tunnel at a Reynolds number of about 5,600,000" (p. 1).

Tests were conducted at dynamic pressure of 50 lb per square foot with lift drag and pitch moment measurements throughout useful angle of attack range for constant flap deflection and position of a low-drag airfoil. Two slots were investigated and practical flap paths were selected for each Slot shape had a negligible effect on the maximum lift coefficient flap deflected, the rounded-entry slot had lower profile drag.

From Introduction: "All results are presented in the form of motions following abrupt displacements of fixed magnitude - 20^o in bank and 15^o in pitch and yaw - from the reference attitude."

Report presenting flight testing using a North American XP-51 airplane with several arrangements of beveled-trailing-edge ailerons to determine the most satisfactory arrangement. Results regarding the aileron configuration, trimming tabs, and factors affecting symmetry of aileron characteristics are provided.

"This report contains the results of tests of a full-scale semispan horizontal tail plane of a bomber airplane. The effects of fabric distortion on the aerodynamic characteristics of the elevator are determined by comparing the aerodynamic characteristics of a fabric-covered elevator with those of a metal-covered elevator. In addition, the results of cutting holes in the balance seal, the effect of fixing transition, the tab effectiveness both sealed and unsealed, and the section drag of this tail plane are presented" (p. 1).

Several tail modifications of the Brewster XSBA-1 scout-bomber were investigated and results compared. Modifications consisted of variation of the chord of the elevator and rudder while the total area of the surfaces is kept constant and variations of the total area of the vertical tail surface. Configuration number 2 reduced trim changes by 50 percent and reduced average elevator control force gradient from 30 to 27 pounds/g. Stick travel required to stall in maneuver was 4.6 inches.

Report presenting an investigation of three interchangeable sealed-gap 0.20-airfoil-chord plain ailerons of different contour on the NACA 65(sub 1)-210 airfoil section. The three aileron contours tested were the true airfoil contour, straight sides, and a beveled trailing edge. Results regarding the aileron effectiveness, aileron hinge moments, lift, pitching moment, and drag are provided.

Report discussing an investigation of the progressive accumulation of load deposits on spark plugs under nonvarying operating conditions. Deposit-weight determinations and photographic observations are presented, and the specific characteristics of deposit accumulation are described.

Report discussing tests on the N9M-2 airplane to evaluate the airplane efficiency factor and to investigate the characteristics of the aeroboost in the elevon control system. The efficiency factor compared reasonably well to conventional airplanes and the aeroboost system and valve-chatter tests were satisfactory.

Report discussing testing to check the improvement of 3 or 4 miles per hour in the maximum speed of the P-51B airplane as a result of sealing the wing-gun access doors and flap-spar lightening holes. Large variations in speed were observed during testing, so additional testing and analysis was carried out to determine the effects of various factors that were suspected of contributing to the inconsistency of the plane's performance.

Report discussing icing and de-icing of the carburetor and supercharger inlet of typical aircraft engine induction systems. A description of the systems used to control and simulate different conditions is provided.

Report discussing the effects of internal coolants injected with fuel on the icing characteristics of a twin-barrel injection carburetor mounted on an engine-stage supercharger assembly. The tests were made at conditions that simulated war emergency power and at a variety of water-fuel ratios, carburetor-air temperatures, and carburetor-air relative humidities.

Report discussing testing of the Douglas A-26B to determine the longitudinal stability and control characteristics. Information about the elevator, stick-fixed and stick-free stability, center of gravity, and flap effects are described.

"The following preliminary drag results obtained in flight on the low-drag wing of the Curtiss XP-60 airplane are given herewith in compliance with the request of the Army Air Corps" (p. 1).

Report presenting a wooden model equipped with a slotted flap that was tested in the two-dimensional tunnel. It represented a wing section of the Curtiss-Wright P-60A airplane and the NACA 66,2-118 section. Results regarding lift characteristics, drag coefficients, and flap deflection characteristics are provided.

Report presenting an examination of the effects of variations in efficiency parameters, including engine economy, aerodynamic efficiency, and structural efficiency, on airplane performance. Efficiency parameters were found to be extremely ineffective in adjusting the airplane performance to its tactical mission as compared to primary parameters like altitude, power, gross weight, and wing area.

Report presenting lift and drag tests made in the two-dimensional tunnel of three airfoil models. The models represented intermediate sections on alternative wings of the XB-32 airplane and were equipped with 0.30 Fowler flaps. Results regarding the Davis model, the C.A.C. model, and low-drag model are provided.

Report presents a series of charts used to demonstrate typical good and undesirable airplane characteristics as determined in flight that were used to facilitate discussion at a series of conferences between the National Advisory Committee, Army, Navy, and representatives of the aircraft industry. For each chart, the purpose of the test, the flight technique used, the items recorded, and the evaluation and interpretation of the data obtained were provided. Additional figures drawn on the board during the conferences are not reproduced in the report.

Report presenting the stability, lateral-control, and stalling characteristics of an airplane modified to accommodate full-span Zap flaps.The static and dynamic longitudinal and lateral stability was satisfactory, but there were some undesirable lateral-control characteristics, including excessive friction and elasticity.

Report presenting a study of comparable information on full-scale spinning results and NACA free-spinning wind-tunnel results in order to determine the degree of reliability of tunnel results in predicting the spinning behavior of airplanes. Satisfactory agreement between model and airplane was found in 16 instances and disagreement was found in 5 instances.

Report discussing testing on the aerodynamic characteristics of two pusher propellers with the same plan form but different airfoil sections behind a slotted flap on the XD-36 airplane. Testing was carried out over the range of blade angles and flap deflections necessary to cover all flight conditions. The effects of flaps and of tip Mach number are described in detail.

"The carburetor and engine-stage supercharger assembly of a fighter aircraft were laboratory-tested to determine the icing characteristics of the induction system under three simulated engine power conditions with varying carburetor-air temperature, relative humidity, simulated-rain injection, rain and fuel temperature, fuel-air ratio, and fuel of different distillation characteristics" (p. 1).

Report discussing the use of a twin-barrel injection carburetor and a supercharger inlet elbow to establish the relation between wet- and dry-bulb temperatures of the de-icing air and time required to recover from air-flow loss due to icing. The tests were performed at several power conditions, icing conditions, temperatures, and dry and humidified air. De-icing time was found to be a function of the nature of the ice formation and of the wet-bulb temperature of the de-icing air.