What happened
On 4 July 1999, an ASAP Summit 2 Powered Parachute, registration C-IFZX, was involved in an accident during a private flight at Cranfield Airfield, Bedfordshire. The aircraft, which had recently been imported from Canada, was operating under a temporary Certificate of Airworthiness Exemption for a public demonstration.
Following a series of taxiing sessions and short flights, the aircraft commenced its third flight of the afternoon. During a left-hand circuit, the aircraft experienced significant directional control issues. Eyewitnesses observed the pilot applying extreme pedal inputs, with the right side of the canopy experiencing high drag. During the maneuver, the canopy appeared to partially collapse, causing the trike unit to pitch up and fall from a low altitude. The aircraft struck the ground on its nose and right side, resulting in serious injuries to the pilot.
The investigation
Investigators examined the aircraft structure, engine, and parachute canopy at the AAIB facility. While the engine and propeller showed no pre-impact defects, the impact caused significant damage to the trike frame, landing gear, and propeller. The canopy and its attachment cables were found to be undamaged.
Because no official rigging instructions were available in the UK at the time of the accident, the investigators relied on technical information provided by the manufacturer via email after the event. This documentation revealed that the steering lines featured specific markers that needed to be aligned with the non-adjustable rigging. The investigation focused on how the steering lines had been tied off to the airframe.
Findings
- The investigation established that the left-side steering line was rigged 28 inches too short, far exceeding the allowable 6-inch deviation for trimming.
- This extreme asymmetry created excessive drag on the left side of the canopy, inducing a continuous turn to the left.
- To counteract this, the pilot would have had to use the right pedal in a manner similar to a landing 'flare', making the aircraft highly unstable and difficult to control.
- No maintenance documents or pilot handling notes were available in the UK to guide the correct setup of the aircraft's controls.