A performance analysis is given to determine whether bondary-layer control by suction might reduce the minimum take-off distance of a four- or five-place airplane. Results indicate that boudary-layer control might be effective in improving the take-off characteristics of this type airplane having wing loading of 10 or more pounds per square foot and aspect ratios of 10 or more.

An investigation was made to determine the effects of boundary-layer control on the landing performance characteristics of a liaison type of airplane having a payload of 1500 pounds and a flight duration of 5 hours. The aspect ratio was varied from 5 to 15, the wing span from 30 to 100 feet, and the brake horsepower from 300 to 1200. The use of boundary-layer control caused reduction in total landing distance (25 to 40 percent), ground-run distance, gliding speed, and stalling speed whereas sinking speed was increased only slightly.

Includes the Committee's Technical reports no. 1-1058, reprinted in v. 1-37.

The landing of a simplified airplane structure, consisting of a uniform beam for the wings, a concentrated mass for the fuselage, and a linear spring for the landing gear, is analyzed exactly and is compared with several approximate solutions. The approximate solutions which neglect elasticity in the determination of landing-gear reaction but consider elasticity in computations of stresses give results of good accuracy and indicate that drop tests in which rigid masses are used may be a satisfactory approach to the landing problem.

This report presents of axial-load fatigue tests on notched specimens of 24S-T3 and 75S-T6 aluminum alloys and normalized SAE 4130 steel with stress-concentration factors of 2.0 (central-circular hole, symmetrical edge notches, and fillets) and 4.0 (symmetrical edge notches and fillets). Fatigue tests were run at several levels of nominal mean stress. Results are compared with previous data for unnotched specimens.