Continuous Disreefing Method for Parachute Opening

Abstract

Although round parachutes have been used for airdrop for over 60 years, damage to canopy fabric and suspension lines still occurs during parachute opening due to the rapid canopy opening and the associated high opening force. Continuous disreefing of round parachutes to slow down the opening and decrease the peak opening force has been discussed in the literature, but no viable continuous disreefing method has ever been developed. In this paper, we present a practical, effective, and low-cost continuous disreefing method that does not use any external electrical or power source, only the opening force and the weight of the payload. The method was successfully demonstrated in a full-scale test from an aircraft using a 10.7-m (35-ft) diameter round parachute. The kinetic energy of the payload at parachute deployment of that test was 11 times higher than that of the standard deployment that the parachute is designed for. In spite of the severe deployment condition, no damage to the parachute was observed after ground impact.