Accident to the Issoire APM30 registered F-HFIK on 17/06/2023 at Pignans

Returning from a local flight, close to a navigation turning point, the aeroplane's horizontal speed gradually decreased. The investigation did not find any particular point of interest at this location. The reduction in the horizontal speed may correspond to a reduction in the airspeed of the aeroplane following a reduction in power, but may also be the result of manoeuvres in the vertical profile, or a combination of the two.

The eyewitnesses saw the aeroplane almost one minute after the horizontal speed had started decreasing. The different angles of view and positions of the witnesses made it possible to determine that its altitude was of the order of 1,500 ft, i.e. a height of 700 ft, and that the aeroplane had changed course in the final moments of the flight. It is therefore probable that the aeroplane was being piloted until the witnesses saw it tip to the left and then downwards, which appears to correspond to a LH asymmetric stall. The aeroplane then continued on a near-vertical downward path with an attitude similar to that of a spin, until it collided with the ground. A fire then broke out.

The examination of the wreckage, limited by the fire damage, was not able to rule out the possibility of a technical failure that might have occurred shortly before the accident. Neither was the investigation able to rule out a sudden incapacitation of the pilot .

The investigation was not able to determine whether the reduction in the aeroplane’s horizontal speed in the seconds leading up to the accident was deliberate or not. Nevertheless, similar speed decreases were observed six times during the flight before the crew of F-HFIK had radio exchanges with the pilot who was carrying out skydiving drops near Le Luc. No problems were reported during the radio exchanges. These horizontal speed decreases were therefore very probably deliberate. They could have been linked to reductions in speed, for example to observe a point of interest, or to manoeuvres in the vertical profile.

Furthermore, altitude information from the transponder (altitude encoder) was no longer available a few minutes after the aeroplane took off. The information collected during the investigation suggests that the altitude encoder was operating normally, and that the pilot deliberately deselected the transmission of altitude information to the radar system. The fact that a pilot deliberately switches off the altitude encoder during the flight may suggest his intention to carry out particular manoeuvres in the vertical profile, and that he has made sure that the control services are not able to detect this.

The height of around 700 ft estimated by the eyewitnesses, at which the loss of control occurred was theoretically just sufficient for a trained pilot to recover from a spin, reacting correctly and very quickly to the situation. The pilot had performed one or two spin and spiral dive recoveries on a CR100 during an aerobatics light instruction day at his previous flying club in 2014. The standard training program for a PPL license does not include recovery from a spin.