History of the Flight
On 17 July 2011 at 1230 UTC, a Piper PA-24-250 Comanche, registration G-BYTI, departed from Sherburn-in-Elmet Airfield on a private flight with two qualified pilots on board. The takeoff run on grass Runway 24 was described as bumpy but within normal limits for a grass surface. After selecting the landing gear up at 500 ft, the pilot observed that the amber indication light did not illuminate, indicating the gear was not up and locked. The emergency landing gear handle was noted to be in approximately the 45º position. The pilot climbed to 2,000 ft and recycled the gear selector multiple times without movement. Arriving at Gamston Airport, the pilot declared a PAN and performed two fly-pasts; ATC confirmed the gear appeared partially retracted. Attempts to lower the gear by normal and emergency means failed. After another fly-past, the pilot departed the circuit to burn fuel, then returned and elected to land in a rapeseed crop field adjacent to asphalt Runway 21. The aircraft touched down in the field, coming to rest after a 27 m ground run. The propeller struck the ground, causing the aircraft to turn through approximately 300º. Both pilots were uninjured and vacated the aircraft without assistance.
Aircraft Examination
After recovery, the landing gear was lowered. A dent was found on the right wing lower skin at the aft edge of the wheel well, consistent with the right main landing gear torque link having contacted the wheel well edge. Examination of the retraction system revealed that a clevis pin attaching the nose landing gear push-pull rod to the torque tube assembly had fouled against the edge of an access hole in a longitudinal beam and jammed. The beam web was slightly bowed inboard, likely from attempts to lower the gear after jamming. The right landing gear oleo was observed to be fully compressed.
Discussion
The pilot considered that the right landing gear oleo deflated during the takeoff run at Sherburn-in-Elmet. This caused the torque link to wedge against the wheel well during retraction, preventing full retraction. The retraction motor likely continued running, potentially causing misalignment in the transmission assembly and reducing clearance between the nose gear push-pull rod and the longitudinal beam, leading to the clevis pin jamming. In this condition, lowering the gear by normal or emergency means was impossible. The reason for the oleo deflation could not be determined from strip examination, but all seals were replaced as a precaution. The aircraft manufacturer was not aware of any similar prior occurrences of the clevis pin fouling on the longitudinal beam.