A summary of spin-recovery parachute experience on light airplanes

From 1977 to 1989, the NASA Langley Research Center conducted stall/spin flight tests of variations of four typical light airplanes. Each was equipped with an identical tail-mounted, spin-recovery parachute system. The system was used 29 times to arrest otherwise unrecoverable spins and was used at least twice on each airplane. The 10.5 ft diameter, ring-slot, spin-recovery parachute with 20 ft attachment lines and drag coefficient of .545 provided recovery from spins at angles of attack of 32 to 79 degrees and rotation rates of 122 to 261 degrees per second in less than 3 1/2 turns.