What happened
On 19 July 2021, a PC12/47E, registered F-HNFC, was conducting a site reconnaissance instruction flight at La Môle aerodrome. The flight was intended to obtain approval for the pilot to operate at this restricted-use aerodrome. The aircraft was accompanied by an instructor and two passengers.
During the approach to runway 0 and 6, the pilot was managing a steep approach slope and late alignment with the runway axis. As the aircraft neared the ground, the pilot performed an aggressive pitch-up input during the flare. This maneuver caused the airspeed to drop significantly. Consequently, the aircraft's Angle of Attack (AOA) protection system was triggered, activating the stick-shaker and the stick-pusher. The stick-pusher induced an abrupt pitch-down movement, causing the nose gear and the propeller to strike the runway.
Following the impact, the pilot initiated a go-around. Although the pilot requested guidance during the destabilized climb, the instructor was slow to take control. After realizing the propeller blades had sustained damage, the instructor decided to terminate the flight and landed the aircraft safely on the reciprocal runway 24.
The investigation
The investigation utilized data from the aircraft's Light Data Recorder (LDR), the Aircraft Condition and Monitoring System (ACMS), aerodrome video surveillance, and radio communications. Investigators examined the flight path, the performance of the Stall and Warning Protection System (SWPS), and the human performance of the crew.
Analysis of the flight data revealed that the pilot had failed to maintain adequate airspeed despite four verbal warnings from the instructor. The investigation also reviewed the instructor's training protocols and the specific environmental challenges of La Môle aerodrome, which features high terrain and complex approach requirements.
Findings
- The primary cause of the hard landing was the activation of the stick-pusher following an excessive pitch-up input during the flare.
- The pilot focused heavily on managing the flight path and runway alignment, which led to a failure to monitor and maintain the required airspeed.
- The instructor provided verbal warnings regarding the decreasing speed but did not intervene physically on the controls until after the impact.
- The instructor had not performed a prior assessment of the student pilot's specific abilities on a less demanding aerodrome before the instruction flight.
- A possible reduction in instructor vigilance contributed to the event, as the instructor had conducted several similar instruction flights that day with varying levels of pilot proficiency.