Accident Overview
On 21 May 2017, at 1012 UTC, a Piper PA-24-250 Comanche, registered G-BYTI, experienced a landing gear collapse after landing at Retford Gamston Airfield, Nottinghamshire. The aircraft was on a private flight with a single crew member and no passengers. The pilot, aged 61, held a Private Pilot’s Licence and had 485 hours total flying experience, with 400 hours on type. He had flown one hour in the previous 90 days and one hour in the previous 28 days. The aircraft sustained damage to the propeller, lower fuselage, and left flap; the crew reported no injuries.
Flight and Maintenance History
This was the first flight after the main landing gear had been refitted following repairs. A new squat (safety) switch was installed prior to the flight, and landing gear functional tests were completed in accordance with published procedures. The pilot’s intention was to fly one circuit with the landing gear down, then land and come to a full stop.
Sequence of Events
The pilot reported that everything was normal with the landing gear indicating down and locked until he applied the brakes after touchdown, at which point the undercarriage collapsed. He stated that he had not operated the landing gear selector lever at any stage of the flight.
Investigation Findings
The maintenance agency reported that the landing gear retraction mechanism was undamaged. The configuration of the ball screw and transmission indicated that the landing gear had been retracted by the electric motor. The circuit breaker for the electric motor was found to have tripped. The safety switch prevents the landing gear from retracting if the left main landing gear leg is compressed, and multiple failures are required for the landing gear to retract without selection.