Report presenting an analysis of data on fuel-vapor loss from fuel tanks during simulated flight obtained by six laboratories to show the effects of individual variables such as altitude, initial fuel temperature, rate of climb, booster-pump agitation, fuel depth, fuel-surface area, types of fuel, and vent-line pressure drop on fuel-vapor loss.

Report discusses an attempt to adapt a method of analysis of V-G data to predict the occurrences of large values of airspeed and acceleration from an SNJ-4 airplane; the data are presented as "flight envelopes". The flight envelopes "predict that, on average, in a stated number of flight hours, one airspeed, one positive acceleration, and one negative acceleration will exceed the envelope with equal probability of the accelerations being experienced at any airspeed" (from Discussion). The analysis method shows promise for predicting flight loads and speeds for airplanes on which loads due to maneuvers predominate.

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 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 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 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 discussing the cooling characteristics of a 14-cylinder double-row radial air-cooled engine in a four-engine airplane. The effects of charge-air flow, cooling-air pressure drop, and fuel-air ratio on the cooling characteristics were measured separately. The cooling equation, rear middle-barrel temperature, cooling-limited manifold pressure, and maximum cruising power versus temperature-limited power are described.

Report discussing a comparison of the antiknock characteristics of triptane with a temperature-sensitive blending agent and of the fuel knock limits with engine cooling limits. Estimates were also made of temperature-limited engine performance at several flight and engine conditions.

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.

Report presenting an investigation of the Supermarine Spitfire airplane equipped with exhaust stacks designed according to the jet-propulsion exhaust-stack system developed by the NACA. An increase in the high speed of the airplane of 6 mph was obtained as compared with the airplane equipped with the Rolls Royce exhaust system. Results regarding performance and exhaust-flame visibility are provided.

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.

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.

"Tests were conducted to determine the effect of several flight variables and several types of fuel agitation on fuel-vapor loss from a fuel tank during flight. Data were obtained from simulated-flight tests, in which the effects of rate of climb, altitude, initial fuel temperature, weathering of fuel, and fuel agitation were investigated; and a correlation between the simulated-flight and actual-flight data was established" (p. 1).

Report presenting testing of a scale model of a twin-engine pursuit airplane in order to investigate the possibility of high-speed diving difficulties and to find remedies for them. Most of the data were obtained in force tests, although some pressure-distribution measurements, elevator hinge moments, and wake surveys were also made. The tests showed that the airplane will experience serious diving moments above lift coefficients of 0.5 at a Mach number of 0.65, and 0.1 at a Mach number of 0.725.

"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).

Report discussing tests on the effect of 2-percent additions of 13 aromatic amines on the knock-limited performance of 28-R fuel in a CFR engine. The amines tested gave good rich mixture response at standard F-4 operating conditions, but were sensitive to engine severity at lean fuel-air ratios.

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.

"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.

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 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 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 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.

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.