What happened
On 28 June 2013, a Piper PA31-350 Navajo Chieftain, registration VQ-TAC, was operating a non-revenue commercial flight from Grand Turk to Providenciales in the Turks and Caicos Islands. Following the arrival at Providenciales, the pilot identified an oily residue on the left inboard flap. Upon inspection, it was discovered that the left main landing gear oleo strut was leaking oil. After consulting with the aircraft's employer, the decision was made to fly the aircraft back to Grand Turk without passengers to facilitate repairs.
During the return flight, the pilot noticed that upon selecting the landing gear to the down position, only the nose landing gear indicated it was down and locked. The pilot aborted the approach and climbed away to investigate the discrepancy. After performing a flypast of the control tower, where observers confirmed that only the nose gear appeared extended, the pilot declared an emergency. The crew committed to a wheels-up landing, with the pilot raising the nose landing gear and feathering both engines prior to touchdown. The landing was completed successfully without fire, though the aircraft sustained damage to the propeller blades and the underside of the fuselage skin.
The investigation
The investigation focused on the mechanical failure of the landing gear system. Post-accident inspections revealed that the left main landing gear had failed to extend fully because the oleo strut had not reached its full extension. This was caused by a twisted and broken O-ring seal on the bottom bearing, which had resulted in the oil leak. This lack of extension caused the torque link to foul the interior of the wheel well, mechanically jamming the gear in place.