What happened
On January 15, 2001, a Piper PA 28 R 201 Arrow 3, registration F-GJCS, was conducting a training flight at Aix-les-Milles airfield. The flight was part of a type rating course for a retractable gear and variable-pitch propeller aircraft, with an instructor and a student pilot on board.
During the fourth circuit of the flight, the instructor simulated a landing gear extension failure by pulling the gear motor circuit breaker. The student pilot followed the standard procedures, ensuring the gear was extended and verifying the green lights were illuminated before landing successfully. Following a touch-and-go maneuver, the instructor simulated a gear retraction failure by leaving the circuit breaker pulled.
While the student pilot initiated emergency procedures, the gear control lever was left in the "retracted" position, even though the green lights remained illuminated. After the aircraft landed, the instructor re-engaged the circuit breaker. At this moment, the left landing gear collapsed, causing the left wing to strike the ground. The aircraft subsequently veered off the runway and came to a halt.
The investigation
Investigators examined the aircraft's landing gear mechanism and found that the gear functioned normally when the circuit breaker was engaged. The aircraft was equipped with a safety device designed to prevent gear retraction while the aircraft is on the ground; however, the investigation revealed that this safety box was inoperative due to a missing contact needle.
Furthermore, the investigation looked into the training procedures used during the flight. It was noted that the instructor had not verified that the gear lever was in the "extended" position, and the visual confirmation of the green lights created a false sense of security that prevented the crew from noticing the error.
Findings
- The primary cause of the accident was the incomplete execution of a simulated gear retraction failure exercise.
- A contributing factor was the failure of the landing gear safety device, which allowed the gear to retract while the aircraft was on the ground.
- The simulation method lacked clarity, as the start and end of the failure exercise were not explicitly communicated during the briefing or during the flight.
- The presence of the green lights, despite the lever being in the retracted position, contributed to a false sense of normalcy that prevented the crew from identifying the error.