What happened
On December 9, 2002, a SOCATA TB 20, registration F-GENS, was performing a technical inspection flight following a major maintenance visit. During the flight, the pilot successfully tested the landing gear extension and retraction cycles, confirming normal operation.
However, while approaching runway 08 at Lognes aerodrome on a tailwind, the pilot set the landing gear lever to the down position and observed that the nose gear failed to lock. Despite following both standard and emergency extension procedures, the gear remained partially extended. After receiving confirmation from another aircraft pilot that the nose gear was stuck at mid-extension, the crew decided to remain airborne for approximately three hours to burn off fuel. Following consultation with the mechanic on board, the pilot elected to land on the unpaved runway 08 with the gear retracted. Emergency services were alerted prior to arrival. The aircraft slid approximately 100 meters along the runway before coming to a stop. The landing caused damage to the propeller, the landing gear doors, and the lower portion of the fuselage.
The investigation
Investigators examined the aircraft while it was supported on jacks and removed the engine cowlings. This inspection revealed that the nose landing gear could be extended normally once the cowlings were removed. The investigation focused on the physical interface between the nose gear door and the engine cowling.
Findings
- The investigation established that the nose gear door, attached to the nose gear strut, was deformed.
- This deformation caused the door to strike the engine cowling, physically obstructing the full extension of the nose gear.
- The primary cause of the incident was insufficient clearance between the gear door and the engine cowling resulting from improper adjustment during recent maintenance.
Safety action
- A service bulletin was issued recommending the replacement of this specific gear door with a model of smaller dimensions to prevent recurrence.