What happened
On August 18, 2001, a Cessna RA 177 RG (registration F-BUMJ) was taxiing at the unpaved parking area of Calvi aerodrome for a private flight. The pilot intended to reach a refueling station quickly. During the taxi maneuver, the nose landing gear retracted, causing the propeller and the lower engine cowling to strike the ground.
The investigation
The investigation established that the aircraft had arrived at the aerodrome on August 16, 2001, following a total electrical failure. Due to the failure, the pilot had been forced to manually deploy the landing gear. However, the pilot did not fully complete the standard procedures following this manual intervention, specifically leaving the landing gear control lever in the "retracted" position.
On the morning of the incident, the pilot moved the aircraft backward using a tow bar to facilitate engine start and refueling. Because the battery had been recharged, the pilot performed a brief pre-start check. When the master switch was engaged, the circuit breakers—including the one for the landing gear pump—were closed.
Findings
At the time of the incident, two of the three necessary conditions for gear retraction were present: the hydraulic pump was powered, and the gear selector was in the retracted position. The third condition, which normally prevents accidental retraction, is a safety switch linked to the nose gear strut that remains inactive while the aircraft's weight is compressing the strut.
It was determined that taxiing over the irregular, unpaved surface likely triggered this safety switch. With the hydraulic pump active and the selector improperly positioned, the nose gear was able to retract, leading to the impact with the ground.