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 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.

Drag testing was conducted in the high-speed wind tunnel of 23 conditions combining six streamline shapes and three conventional cowling-fuselage bodies. All of the models were tested in combination with a wing in order to include wing-fuselage interference effects. The critical speeds of combinations tested were, in general, determined by the wing-fuselage juncture.

Report presenting a series of boundary-layer surveys over the surface of an NACA 0012 airfoil at zero lift. Results regarding the pressure distribution, laminar boundary layer, transition, turbulent boundary layer, drag, and skin friction are provided.

Report presenting information regarding the calculation of the transition point, velocity distribution in laminar and turbulent boundary layers, and thickness of the boundary layer, both laminar and turbulent, of low-drag wings.

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 a discussion of the problem of establishing a rational unsymmetrical gust load criterion from available data on gust structure and it is indicated that the problem cannot be solved at the present state of knowledge without more analysis.

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.

Report presenting tests in the 4- by 6-foot vertical wind tunnel of an NACA 0009 airfoil with a 30-percent-chord flap with a small amount of aerodynamic balance. In the investigation, the effect of balance nose shape and gap at the nose of the flap has been determined. The results indicate that, in general, the lift effectiveness of the flap was unaffected by the addition of a small amount of aerodynamic overhang, and the balance effectiveness of the flap was increased.

Report presenting testing of an NACA 0009 airfoil with a 30-percent-chord flap with a 49.5-percent flap-chord balance with various nose shapes and two gaps. The results indicated that the flap is overbalanced when deflected, regardless of nose shape. Results regarding lift, hinge moment of flap, drag, pitching moment, and effect of differential balancing tab are provided.

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.

From General Analysis: "The purpose of part I of this paper is to show how the loading that gives the minimum induced energy loss can be obtained from rather elementary considerations and to present design charts from which such a plan form can be quickly obtained for any set of design conditions."

Report presenting aerodynamic tests of a 300-pound M-31 demolition bomb. Force tests at a range of angles of attack were made at Mach number 0.725, which corresponds to a speed of 810 feet per second at sea level. Results regard the drag, lift, and pitching moment are provided.

Report presenting air-flow surveys made in the region of the tail plane of a typical twin-engine tractor monoplane model with tail surfaces removed. The surveys were made with propellers removed and operating and for both cases included the conditions for flaps retracted and flaps deflected 50 degrees.

Report presenting an investigation to determine whether the difference in the spanwise loading of the two types of aircraft were responsible for the differences in spin characteristics, particularly in regards to angle of attack.

Supplement using data from a previous report to show the cargo that can be carried at various ranges, pounds of cargo that can be carried per pound of fuel, and other graphs to simplify the problem of determining which cargo can be carried at any range. The assumptions, parameters, and equations from the original report are carried over in the supplement.

Report presenting a study of the performance of bombers powered by two, four, and six 3000-horsepower engines supercharged to 35,000 feet. The performances are computed and are based on drag coefficients equal to the best obtained on modern airplanes and on weight estimates obtained from modern Army Air Forces airplanes. A chart is provided with the coordinates of power loading and wing loading noted so that all performances can be compared.

Report presenting methods for determining the jet-boundary corrections to the downwash behind models in rectangular wind tunnels. The methods take into account the tunnel dimensions, the type of jet, the span loading of the model, the geometric position of the wind and of the tail in the tunnel, the displacement of the wing wake, and the effect of the slipstream.

Report presenting the results of spin-tunnel testing of 65 models indicating that when a single-engine type airplane was simulated with mass distributed along the fuselage, the rudder was the predominant control for recovery. The primary focus of this investigation is to determine the spinning characteristics of the airplane and to develop a useful criterion for predicting the optimum control manipulation for recovery.

Report presenting samples of 17S-T and 24S-T aluminum alloys subjected to accelerated corrosion tests in which the corrosion period was established at 6 hours for samples that had been etched to produce a uniform surface. The results indicate the types of corrosion attack, which are described in standard terminology, and may form a basis for estimating the resistance of the material to corrosion by a comparison of the relative depth and frequency of the corrosive attacks.