Effect of High-lift Devices on the Low-speed Static Lateral and Yawing Stability Characteristics of an Untapered 45 Degrees Sweptback Wing

Results of a low-speed wind-tunnel investigation to determine the effect of high-lift devices on the static lateral stability derivatives and the yawing derivatives of an untapered 45 degrees sweptback wing are presented. The tests were made in the curved-flow test section of the Langley stability tunnel at a Reynolds number of 1.1 X 10 to the sixth power

Analytical Investigation of the Dynamic Behavior of a Nonlifting Manned Reentry Vehicle

An analytic investigation was made of the dynamic behavior of a nonlifting manned reentry vehicle as it descended through the atmosphere. The investigation included the effects of variations in the aerodynamic stability derivatives, the spin rate, reentry angle, and velocity. The effect of geostrophic winds and of employing a drogue parachute for stability purposes were also investigated. It was found that for the portion of the flight above a Mach number of 1 a moderate amount of negative damping could be tolerated but below a Mach number of 1 good damping is necessary. The low-speed stability could be improved by employing a drogue parachute. The effectiveness of the drogue parachute was increased when attached around the periphery of the rear of the vehicle rather than at the center. Neither moderate amounts of spin or the geostrophic winds had appreciable effects on the stability of the vehicle. The geostrophic winds and the reentry angle or velocity all showed important effects on the range covered by the reentry flight path

Experimental Determination of the Effect of Horizontal-Tail Size, Tail Length, and Vertical Location on Low-Speed Static Longitudinal Stability and Damping Pitch of a Model Having 45 Degree Sweptback Wing and Tail Surfaces

Report presents the results of an investigation conducted in the Langley stability tunnel to determine the effects of horizontal tails of various sizes and at various tail lengths (when loaded on the fuselage center line) and also the effects of vertical location of the horizontal tail relative to the wing on the low-speed static longitudinal stability and on the steady-state rotary damping in pitch for a complete-model configuration. The wing and tail surfaces had the quarter-chord lines swept back 45 degrees and had aspect ratios of 4. The results of the investigation showed that, in agreement with analytical considerations, the contribution of the horizontal tail to static longitudinal stability was related directly to the tail size and length; whereas, its contribution to damping in pitch was related directly to tail size and the square of tail length

An Investigation at Low Speed of the Spin Instability of Mortar-Shell Tails

An investigation was made in the Langley stability tunnel to study the influence of number of fins, fin shrouding, and fin aspect ratio on the spin instability of mortar-shell tail surfaces. It was found that the 12-fin tails tested spun less rapidly throughout the angle-of-yaw range than did the 6-fin tails and that fin shrouding reduced the spin encountered by a large amount