scope:

Description of Driving Event:

During a drop test at the NASA Plum Tree Island Test Facility, a model was severely damaged due to failure of its parachute recovery system. The failure of the recovery system resulted from teflon cloth jamming closed the canopy compartment lockoff flaps. The teflon cloth had been wrapped around the suspension lines to expedite extraction of the folded lines.

The parachute contractor design personnel chose to add the cloth because its lubricating effect on the suspension lines and the resultant lowering of the force required to extract the lines. The information concerning the design change and lower opening force was transmitted to the research project engineer by telephone conversation. Significantly, no confirming strip-out load tests were performed with the teflon wrapped lines prior to using them in an actual test.

The primary finding of the investigation committee was that teflon cloth jamming prevented the bag from opening and the canopy extracting.