Report presenting force-test measurements in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the characteristics of an NACA 0015 airfoil equipped with a straight-contour plain flap with a chord 30 percent of the airfoil chord. Results regarding the lift, hinge moment of flap, pitching moment, and drag are provided.

Report presenting a theoretical study of the effects of aileron adverse yawing moment on lateral maneuverability at a high lift coefficient. The study included the effects of changes in effective dihedral angle, vertical-tail area, and tail length.

"Three widely different nose shapes were tested on a fuselage alone and on a complete model in the UACA stability tunnel to investigate the effect of cowling shape on stability characteristics. The results are presented in the form of charts which show the variation in the aerodynamic characteristics with the three nose shapes for the propeller-removed condition over a wide range of angles of attack and yaw. The results of the investigation indicated that large changes in the cowling shape produced relatively small changes in the aerodynamic characteristics" (p. 1).

Report presenting ground-effect tests made in the LMAL 7- by 10-foot tunnel of a model of a low-wing, pursuit-type airplane equipped with a full-span 25-percent-chord slotted flap. Testing occurred at different heights and power conditions, and two stabilizer and elevator settings were used at each condition. Results indicated that the elevator deflection required for landing in a three-point attitude with the full-span slotted flap was considerably greater than that required with a partial-span split flap.

Report presenting an analysis of experimental and theoretical data, which indicates that critical evaluation of fuel performance, especially economy, must be made in the engine. Data show that heating value is, from the aspect of fuel economy, not so important an aviation-fuel specification as believed. The knock ratings of fuels are affected by spark advance.

Report presenting tests of 10-foot diameter, single- and dual-rotating tractor propellers with two to eight blades conducted in the 20-foot propeller-research tunnel. The blades were 50 percent wider than those used in previous investigations. Results regarding the effect of dual rotation and effect of solidity are provided.