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.

From Introduction: "This report presents the results of these tests which cover a total of about 70 flying hours on this airplane."

Report presenting tests conducted on a steel cylinder barrel with aluminum fins in order to determine the heat-transfer coefficients of the cylinder and the excellence of the bond between the steel barrel and the aluminum fins. Results regarding the heat-transfer tests and physical tests are provided.

Report presenting an investigation to obtain data on the vertical and horizontal gusts in the atmosphere by reworking accelerometers and airspeed records from past investigations of vertical gusts. The results indicate that the vertical and horizontal gusts are of about equal intensity in the atmosphere.

Report presenting testing of a steel cylinder barrel with aluminum fins in order to evaluate the effect of using preformed aluminum fins on a steel barrel or aluminum barrel. Results regarding the heat-transfer tests and physical tests are provided.

Report presenting testing of two engine cylinder barrels with aluminum fins. The primary purpose was to determine the heat-transfer coefficients and the excellence of the bonds between the aluminum fins and the aluminum base and between the aluminum base and the steel of the two barrels when manufactured by a large-volume production method.

Report presenting testing of a steel cylinder barrel with aluminum fins of the optimum spacing of 0.090 inch. The primary purpose is to determine the excellence of the thermal bonds between the aluminum fins and the aluminum base and between the aluminum base and the steel and to compare the heat transfer of the barrel with that of barrels with a fin space of 0.052 inch.

Report presenting some statistical measurements of the accelerations encountered in gusty air over a period of years in order to determine the loads to which airplanes may be subjected. The statistical measurements have been evaluated to yield either effective or true gust velocities as applied to the wings of airplanes.

Report presenting testing to determine the boundary layer characteristics and profile drag of the NACA 35-215 airfoil section at high Reynolds numbers. The results indicated that a forward movement of the transition point occurred at about 3 percent of the chord due to operation of the engines and propellers.

"At the request of the Bureau of Aeronautics, Navy Department, tests were made in the 7- by 10-foot wind tunnel of the 1/8-scale model of the Brewster F2A airplane. The object of the tests was to determine the power-off static lateral and longitudinal stability and control of the complete model" (p. 1).

Report presenting an investigation in the 7- by 10-foot wind tunnel of an NACA 23012 airfoil with a 30 percent-chord Maxwell leading-edge slat and a slotted and a split flap. The main purpose was to determine the optimum slot cap of the Maxwell slat for, and the aerodynamic section characteristics of, the airfoil with several deflections for both types of flaps. Curves of lift, drag, and pitching-moment characteristics for optimum arrangements are provided.

Report presenting testing of solid naphthalene melted and used as a fuel in a modified CFR variable-compression engine at a speed of 2000 rpm. Information regarding its knock limit, mean effective pressures, and some of its other properties are provided.

"At the request of the Bureau of Aeronautics, Navy Department, tests were made in the 7- by 10-foot wind tunnel of the 1/8-scale model of the Brewster F2A airplane with full-span slotted flaps. The object of the tests was to determine the power-on static lateral and longitudinal stability of the complete model with a new wing which had a full-span slotted flap and a plain and slot-lip aileron for lateral control" (p. 1).

Report presenting static tests on four full-scale two-bladed propellers differing only in blade sections at blade angles from 0 to 20 degrees at the three-quarters radius. Two of the propellers were also tested as three-bladed propellers. For all of the propellers tested, the highest value of the static thrust figure of merit occurred at a tip-speed ratio between 0.7 and 0.9; the highest efficiency in flight may be expected in the same range of tip-speed ratios.

Report presenting static tests on two full-scale three-bladed propellers differing only in blade sections at blade angles from 0 to 20 degrees at the three-quarters radius.

Report presenting force tests conducted on a model of a section of the XP-63 horizontal tail surface in the 4- by 6-foot closed-throat vertical wing tunnel. The angle-of-attack range was from the negative to the positive stall for all flap deflections.

Tests of four 10-foot propellers were made in the propeller-research tunnel for the Army Air Corps to check flight and static thrust test results made on several propellers embodying Clark Y and modified NACA 16-series sections. These propellers were identical as to diameter and activity factor and very closely identical in thickness ratio and pitch distribution. The blades embodied sections with both single- and double-cambered Clark Y, modified NACA 16-series, and a combination of Clark Y and modified NACA-16 airfoils. Tests covered a range of blade angles from 20 deg. to 70 deg., and were all made at tip speeds below 280 feet per second. Although these tests were not conclusive in themselves, owing to the conditions under which they were made, the results seem to check the flight and static tests as closely as would be expected.

Report presenting tests of two 10-foot Hamilton Standard propellers to determine the relative merits of the Clark Y and NACA 16-series sections and to determine the negative thrust available at negative angles. Little difference was noted between propellers at peak efficiency for the low Mach numbers used in the tunnel tests.

Report presenting tests on the Bell XP-63 wing root section fitted with an 0.18c split flap hinged at approximately 0.805c on the lower surface. The tests were conducted to determine the effect of a 10 degree deflection of the split flap on the drag characteristics of the model at low lift coefficients.

"Additional tests as recommended in reference 1 were made in the 7- by 10-foot wind tunnel of the 1/8-scale model of the Brewster F2A airplane to determine the angle of attack of horizontal tail and the elevator angles required for trim with flaps down" (p. 1).

Report presenting an investigation in the 7- by 10-foot wind tunnel of an NACA 23012 airfoil with an 18.05-percent-chord Maxwell leading-edge slat and with a slotted and a split flap. The main purpose of the investigation was to determine the optimum slot gap of the Maxwell slat for, and the aerodynamic section characteristics of, the airfoil with several deflections of both types of flap.

"Preliminary two-dimensional tests of the hinge-moment characteristics of a 0.1725c internally balanced aileron on the subject XP-60 wing section indicated that more internal balance would be required if light stick forces were to be obtained at high speeds. The present series of tests were therefore undertaken in order to investigate methods of reducing the slope of the hinge-moment curve while still maintaining the required aileron effectiveness" (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 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.