What happened
On May 7, 2016, a student pilot was performing his first solo flight in an Alexander Schleicher ASK-13 at the Saint-Hubert Airfield (EBSH). The flight was part of an intensive nine-day training course. While the instructor monitored the flight from the ground, the aircraft appeared to be on a stable glide path during the final approach. However, just seconds before touchdown, the aircraft's nose pitched downward significantly. The front underside of the fuselage struck the ground heavily a few meters before the runway threshold. The impact caused the aircraft to rebound and skid 96 meters along the field. The pilot suffered serious injuries, specifically vertebral fractures, and briefly lost consciousness.
The investigation
Investigators analyzed the aircraft's configuration and the flight's history. The Alexander Schleicher ASK-13 was found to be airworthy and properly weighted, though the single-occupant configuration meant the aircraft was roughly 15-20% lighter than during previous dual training flights, requiring different control inputs. Video footage captured by a bystander revealed that while the airbrakes were initially only partially deployed, they were extended further during the final seconds of the approach. The investigation also considered environmental factors, noting that the low position of the sun could have distorted the pilot's perception of altitude.
Findings
- The primary cause of the accident was the student pilot's failure to pull back on the elevator control to flare the aircraft before impact, likely due to intense focus on the airspeed indicator.
- An indirect factor involved the improper manipulation of the airbrake handle, which led to a sudden decrease in airspeed during short final.
- Contributing factors included the psychological stress of performing a first solo flight and the change in aircraft handling characteristics due to the lighter weight of a single occupant.
- The low sun angle may have contributed to an incorrect estimation of the aircraft's altitude relative to the ground.