Summary: An investigation of the power-off longitudinal stability characteristics of a tailless all-wing airplane model with various wing modifications has been made in the Langley free-flight tunnel. Force and tuft tests were made on the model in the original condition, with the wing tips rotated for washout, with rectangular and swept-forward tips, and with various slat arrangements. Flight tests were made with the original wing and with the original wing equipped with the most promising modifications. The results indicated that changes in tip plan form or rotation of the wing tips did not appreciably reduce the instability at high lift coefficients. Addition of wing slats, however, improved the longitudinal stability at the stall when the slat extended far enough inboard to cover the area that tended to stall first.

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An investigation was made to determine the effects of wing inboard plan-form modifications on the lift, drag, and longitudinal characteristics of a rocket-propelled free-flight model. The model had a body of fineness ration 17.4, a modified wing with a basic plan form swept back 52.5 degrees and an aspect ratio of 3, and inline horizontal tail surfaces which were aerodynamically pulsed continuously throughout the flight.