What happened
On 12 May 2018, a Socata TB2 and registration G-CORB was conducting a private flight from Gloucestershire Airport. While approaching the grass runway at Glenforsa Airport, the pilot was warned of potential wind shear and advised to use minimal braking due to wet surface conditions. To maximize roll-out distance, the pilot intended to land near the runway designator numbers. However, a strong downdraught at approximately 10 feet altitude caused a hard landing slightly short of the target area. During this maneuver, the left mainwheel struck the vertical edge of the concrete runway designator numbers.
Following the impact, the pilot aborted the landing and diverted to Oban Airport. Upon arrival, the pilot requested a low pass to inspect the aircraft's condition. An observer in a nearby aircraft noted that the left landing gear was misaligned and the tyre had separated from the rim, although the cockpit's landing gear indicators remained green. During the subsequent landing on Runway 01 at Oban, the aircraft touched down on the right mainwheel first. As the left mainwheel made contact, the gear collapsed, causing the aircraft to veer off the runway and come to rest on the grass. There were no injuries to the pilot or the two passengers.
The investigation
The investigation focused on the sequence of events at both Glenforsa and Oban airports. At Glenforsa, it was established that the aircraft's wheels had sunk into the grass, leading the left wheel to strike the concrete runway numbers. The investigation also examined the state of the aircraft's landing gear prior to the second landing attempt. It was noted that while the gear appeared visually damaged to external observers, the internal cockpit systems still indicated the gear was down and locked.
Findings
- The initial damage to the landing gear was caused by the left mainwheel striking the concrete runway designator numbers at Glenforsa.
- The left landing gear collapsed during the touchdown at Oban Airport because the gear was already structurally compromised.
- The aircraft's tyre had detached from the wheel rim prior to the second landing attempt.
- The runway designator numbers at Glenforsa presented a hidden hazard as they were sunk into the grass, and the airport's safety information did not specifically warn of this feature.