Amateur-built FREEDOM N2854L accident near Green Township, New Jersey

Probable cause

The pilot's improper preflight setup of the aircraft's foldable wing, during which he incorrectly attached a nylon strap loop pull handle, instead of the steel cable shackle at the end of the strap, to its mounting hook. The nylon strap failed in flight, resulting in a partial collapse of the wing and the aircraft's descent and impact with terrain.

NTSB analysis

The noncertificated pilot planned to conduct a local flight in an experimental amateur-built weight-shift control aircraft that he built. A witness reported that the pilot had difficulty with one of the cables as he prepared the wing (which was foldable for storage) for flight and that he used a ratchet strap to help pull into place a cable that held the wing open for flight. Shortly after takeoff, when the aircraft was at an altitude of about 50 ft, the wing partially folded, and the aircraft descended into the ground.

A postaccident examination of the wing revealed that the cross-bar restraint cable, which held the wing in its open position, was not attached at its shackle and hook fitting at the rear of the wing keel tube. Additionally, the nylon webbing strap, which was attached to the steel cable shackle and designed to be used as a handle to pull the cable in place, was torn and separated from one mounting point and torn but still attached to the other mounting point. The shackle likely did not disengage from the hook during flight because the locking mechanism on the hook remained intact, was undamaged, and functioned normally. Given the witness report of the pilot's difficulty pulling the crossbar restraint cable into place, as well as the damage to the nylon webbing handle used to pull the cable, it is likely that the pilot inadvertently placed the nylon handle in the attachment hook instead of the steel shackle. Shortly after takeoff, the nylon handle likely tore from its mount, which caused the wing to partially fold, precluding the aircraft's continued flight.

Text from the NTSB. Open the NTSB docket for ERA17FA265 for the full record.