Describes the types of "materials and hardware used in aircraft construction and repair."

Analysis was made to determine characteristics required of a balancing-tab system for ailerons in order to reduce aileron stick forces to any desired magnitude. Series of calculations based on section data were made to determine balancing-tab systems of various chord tabs and ailerons that will give, for a particular airplane, zero rate of aileron hinge moment with aileron deflection and yet will produce same maximum rate of roll as a plain unbalanced 15-percent chord aileron of same span. Effects of rolling velocity and of forces in tab link on aileron hinge moments have been included.

Two airfoil plans were used for propeller blades. One is modified Clark Y section designed for structural reliability and the second an NACA 16 airfoil section designed to produce minimum aerodynamic losses. At low air speeds, the propeller designed for aerodynamic effects showed a gain of from 1.5 to 4.0 percent in propulsive efficiency over the conventional type depending on the pitch. Because of the numerous variables involved, the effect of each one on the aerodynamic characteristics of the propellers could not be isolated.

Report presenting testing of a Pratt & Whitney R-1830-43 engine mounted in a B-24D nacelle in the full-scale wind tunnel in order to investigation the potential improvements of fuel economy. Suggestions for improving the cruising power and cruising range by operating at specified fuel-air ratios are provided.

Report presenting tests conducted with an air-cooled cylinder on two fuels rated at approximately 100-octane number by the C.F.R. aviation method with and without a 40-percent addition of an aromatic mixture. The aromatic mixture consisted of 50 percent toluene, 37.5 percent xylene, and 12.5 percent benzene. Results regarding engine performance and engine temperature are provided.

Report presenting an investigation in the 20-foot propeller-research tunnel to determine the effect of variations in angle of pitch on the aerodynamic characteristics of several propeller combinations. The combinations investigated included two-, three-, four-, and six-blade single-rotating propellers and a six-blade dual-rotating propeller on a nacelle with four angles of thrust axis. The propulsive efficiency was found to decrease as the angle of pitch increased.

"The effects of direction of propeller rotation on factors affecting the longitudinal stability of the XB-28 airplane were measured on a 1/10-scale model in the 7- by 10-foot tunnel of the Ames Aeronautical Laboratory. The main effect observed was that caused by regions of high downwash behind the nacelles (power off as well as power on with flaps neutral). The optimum direction of propeller rotation, both propellers rotating up toward the fuselage, shifted this region off the horizontal tail and thus removed its destabilizing effect" (p. 1).

"Laboratory tests were made to obtain information on the load-resisting properties of X76S-T aluminum alloy when subjected to static, impact, and repeated loads. Results are presented from static-load test of unnotched specimens in tension and in torsion and of notched specimens in tension. Charpy impact values obtained from bend tests on notched specimens and tension impact values for both notched and unnotched specimens tested at several different temperatures are included" (p. 1).

Pressure drop calculations are shown for He cooled power plants ranging from 400,000 kw to 30,000 kw.

Report presenting an exploration of fatigue stresses of some wrought aluminum alloys, including charts that cover different ranges of stress and number of cycles.

Investigations were undertaken to improve the ailerons of a P-51 fighter so as to obtain greater effectiveness without increasing the stick forces. Modifications consisted of increasing the deflection range of the aileron to 70 percent and changing the original concave section to a thick section with beveled trailing edge. Results of the modified ailerons showed an increase in effectiveness over the original aileron of 70 percent at low speed and 55 percent at high speeds.

None

Report presenting testing of a model of the Douglas DC-3 airplane for several loading conditions. The load factor for the complete airplane, for the horizontal tail, and the force to start moving the elevator downward were estimated for some steady spins. Testing occurred at 2500 feet and 10,000 feet.

Bulletin presenting a discussion of information as to the influence on spins and spin recovery of the wing loading and load distribution of present-day pursuit airplanes. The high wing loadings results in high rates of descent and large control forces for recovery.

Bulletin presenting a study of several airfoils, including a conventional NACA 23021 and some low-drag airfoils for which the thickness had been increased, as smooth airfoils and after the application of a standard roughness. The results show some of the airfoils to be critical to separation resulting from such flow disturbances.

Designed to familiarize Army Air Forces personnel with publications, forms, and policies, in order to ensure efficient aircraft maintenance and standardized practices.

A preliminary study of pitching-moment data on tapered wings indicated that excellent agreement with test data was obtained by locating the quarter-chord point of the average chord on the average quarter-chord point of the semispan. The study was therefore extended to include most of the available data on tapered-wing models tested by the NACA.

Front: Text describes action on various war fronts: Allied raids effective -- Stilwell in India -- Chinese repulse Japs -- Planes sink subs -- Against overconfidence -- Private buys $3,700 war bonds -- U.S. mission in Britain points to new fronts -- Labor will be 'frozen' -- Camacho asks for war -- 'Freeze' fish, razors -- New registration set -- Recruiting for WAAC -- Millions in war work -- Bombers to pop out like Model T's at Willow Run -- Kurdish revolt crushed -- Heavy action at Kharkov -- Himmler's aid wounded -- Axis drive in Libya -- RAF ruins Genoa. Large world map is keyed to text and illustrates time zones around the world. Inset maps show area occupied by Japanese troops near Chungking -- Nazi drives and Soviet attacks near Kharkov. Includes photographs: Beaufort torpedo-bombers under mass production in Australia -- Sec. Hull -- Lt. Gen. Arnold -- Lt. Gen. Somervell -- Rear Adm. Towers -- WAAC officer's winter and summer uniforms and Auxiliary's winter uniform -- Flying B-24 -- Bren Gun carriers in action -- Long-barrelled Russian rifles -- British 25 pounder fires on the enemy in Libya -- Hurricane bomber -- Training for motor torpedo boat …

Front: Text describes action on various war fronts: Cologne and Essen flattened -- Tiny subs find Sydney ready -- the Japanese "save face" -- Army of 4 1/2 million for '42 -- Mexico welcomed into war -- Rommel's forces turned -- Hitler's hangman dies -- Poison gas used in China -- Armies shift in Russia. Large world map is keyed to text and illustrates time zones around the world. Inset maps show Libyan battle, Dutch Harbor, Axis drives and British attacks at Libyan; Unalaska Is.; Unalaska Bay. Includes photographs: Producing the big seacoast rifles; Red gound defense on the Russian front; Nazis' Focke-Wulf 190 fighter; Yanks saw a motor show put on by Aussies; 4-motored Stirling bombers used over Cologne. Back: Enemy Tanks Are Vulnerable. Includes 10 photographs with descriptive text below each.

Front: Text describes action on various war fronts: Midway, China, India, Libya, RAF, Australia, Madagascar, East Indies, Russia; The second front: Allies, production. Large world map is keyed to text and illustrates time zones around the world. Inset maps show Russian Front; Midway Islands; Battle of Libya. Includes 15 photographs. Back: Color illustration of a German Gruppe. Text and drawings detailing the organization, uniforms, insignia and weapons of the basic German army unit.

Front: Text describes action on various war fronts. Large world map is keyed to text and illustrates time zones around the world. Includes inset maps: Strategic distances in the North Pacific ; Attu Island ; the Rat Island group ; Jap drives [in China]. Photographs: Jungle fighting; Battle of Carriers; Planes that hit the enemy; Swimming through flames; Tomahawk takes it. Back: "These are some of the weapons which checked Hitler's armies." Includes photographs: Moving in column to the attack -- Armored train alert -- Light armored cars -- Anti-aircraft alarm -- Ready to fire -- Formation to the front -- Anti-aircraft machine gun -- Woods used for cover -- Mortar ready to fire -- Amphibian tanks on land... -- Horse-drawn anti-tank gun -- ... and on the sea.

Front: Text describes action on various war fronts. Large world map is keyed to text and illustrates time zones around the world. Includes inset maps: The siege of Sevastopol ; Theater of operations in the Aleutians. Photographs: Battle along the Atlantic; Damaged Japanese cruiser following Battle of Midway; Loading supplies; Moving on Moulmein; Russian Front; Trying Aussie favorite; West Coast patrol; Raising damaged Japanese midget sub. Back: Text describes the principal combat ships in fleets around the world. Includes photos of battleship, aircraft carrier, cruiser, submarine, destroyer, torpedo boat, minesweeper, and net tender.

A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are given for 19 plates, ranging in thickness from 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pressure for the beginning of permanent set as a function of the dimensions of the plate and the tensile properties of the material.

From Summary: "Normal-pressure tests were made of 56 rectangular plates with clamped edges and of 5 plats with freely supported edges. Pressure was applied and the center deflection and the permanent set at the center were measured. For some of the plates, strains and contours were measured in addition."