What happened
On August 13, 2003, an Aeromot AMT 100 motor glider, registration F-CHXC, was performing a private flight from Merville to Arras. During the approach to runway 23, the pilot observed a tractor in a field near the runway threshold. To avoid flying over the vehicle, the pilot maneuvered the aircraft to the left, aligning the glider with the taxiway markings that separate the runway from the taxiway.
Driven by a desire to land quickly because a passenger was waiting, the pilot elected not to perform a go-around. The aircraft landed on the unpaved taxiway. As the glider began taxiing, the right landing gear collapsed, followed by the left gear. The aircraft slid approximately 20 meters before performing a 180-degree turn and coming to a halt near the threshold of runway 23. The incident resulted in damage to the propeller.
The investigation
The investigation focused on the pilot's landing procedures and the mechanical state of the landing gear mechanism. The pilot stated that he had extended the gear while flying over the aerodrome during a headwind leg. While he checked the landing gear indicator light during the headwind leg, he did not re-verify the gear status during the final approach, noting that his attention was divided by the need to avoid the tractor and the glare of the sun.
Technical examination of the gear control mechanism revealed a critical issue with the cockpit interface. The landing gear lever uses metal contact blades to trigger the cockpit warning lights and alarms. Investigators found that these two metal blades were deformed, allowing them to provide a "gear locked" indication even when the lever was in the "extended" position but the gear was not actually mechanically locked.
Findings
- The pilot failed to lock the landing gear in the down position.
- The pilot's decision to land on the taxiway was influenced by a desire to avoid a tractor and a sense of urgency to meet a passenger.
- The pilot did not perform a secondary verification of the gear status during the final approach.
- A mechanical defect in the cockpit indicator contacts provided a false sense of security by displaying a locked status despite the gear being unlocked.