A theory of three-dimensional parachute dynamic stability
Date of Original Version
The three-dimensional motion of a freely descending parachute is studied with a five-degreeof- freedom analysis (the roll motion is neglected). The equations of motion are nondimensionalized and the resulting parameters discussed. Exact expressions are given for the longitudinal and lateral small-disturbance stability of the familiar gliding motion of parachutes. The breakdown of these small-disturbance expressions is illustrated by exact large-disturbance studies. A large longitudinal disturbance of most parachutes will result in a large pitching motion, whereas a large lateral (out of the glide plane) disturbance will usually cause a large angle vertical coning motion. Exact algebraic expressions are given for the coning mode, which is a stable rotation, and a small amount of available coning data is included for comparison. Some parametric computer studies of the various motions are also shown.
Journal of Aircraft
White, Frank M., and Dean F. Wolfj. "A theory of three-dimensional parachute dynamic stability." Journal of Aircraft 5, 1 (1968): 86-92. doi:10.2514/3.43912.