What happened
On July 11, 2009, a Piper PA 28, registered F-BUUN, and a Jodel D 140 R, registered F-PTSH, departed from Biscarrosse, France, for a flight to Vichy. The two aircraft were flying in formation, with the pilot of the Piper acting as the formation leader, responsible for both navigation and all radio communications with air traffic control.
During the flight, the two aircraft were flying in close proximity. At approximately 8:57 UTC, the pilot of the Jodel reported to air traffic control that his aircraft had been struck by the Piper and was experiencing heavy vibrations. The Jodel pilot subsequently diverted toward Clermont-Ferrand to inspect the landing gear before performing an emergency landing in a field.
Simultaneously, the pilot of the Piper PA 28 lost control of the aircraft following the impact, leading to a fatal collision with the ground in the commune of Manzat. The impact resulted in two fatalities (the pilot and one passenger aboard the Piper) and the total destruction of the Piper PA 28. The Jodel aircraft sustained significant damage but remained airborne.
The investigation
The BEA investigation utilized high-precision GPS data from both aircraft to reconstruct the flight paths, as radar data proved too imprecise due to the proximity of the two transponders. The analysis revealed that while the aircraft had maintained a relatively stable separation for much of the flight, the Jodel began a convergent course toward the Piper in the minutes preceding the collision.
Investigators also examined the cockpit visibility of both aircraft. The Piper's design featured a cabin ceiling that created a significant blind spot above the pilot, making an aircraft at a higher altitude nearly invisible. Conversely, the Jodel's cockpit offered limited visibility to the rear right and downward, particularly due to the wing structure. Furthermore, the investigation noted that the pilots had not conducted a formal formation flight briefing prior to departure, leaving relative positions and separation responsibilities undefined.
Findings
- The primary cause of the accident was the loss of visual contact between the pilots during formation flight.
- The collision occurred when the Jodel's propeller struck the Piper's fuselage, causing the separation of the Piper's tail section and subsequent loss of control.
- A lack of flight preparation and the absence of a specific briefing regarding formation separation contributed to the event.
- Inadequate communication between the pilots regarding their relative positions during the flight was a contributing factor.
- Limited cockpit visibility in both aircraft types prevented the maintenance of continuous visual contact during the convergence phase.
- Potential contributing factors included increased pilot workload during the approach phase and fatigue of the Piper pilot.