What happened
On March 30, 2015, at approximately 10:30 local time, a Rans S-6ES ultralight, registration 974GQ, departed from the Cambaie airfield in Réunion for a commercial sightseeing flight. The aircraft was carrying the pilot and one passenger. During the flight, a witness near Tan Rouge reported hearing an explosion and observed the aircraft flying at a very low altitude with what appeared to be a trailing piece of fabric. The aircraft subsequently struck the ground, resulting in two fatalities and the total destruction of the aircraft.
The investigation
The BEA examined the wreckage and found that the upper wing covering (extrados) of the right wing had been torn away from the structure. The investigation revealed that the leading-edge metal plate had become detached from the leading-edge tube due to a combination of localized corrosion and adhesive failure. This movement caused the metal plate to rub against the wing ribs, leaving visible friction marks.
Furthermore, the investigation identified several deviations from the manufacturer's assembly instructions. The lower wing covering (intrados) had been installed before the upper covering, and the assembly lacked the required polycarbonate reinforcement strips. The investigation also noted that the aircraft's ballistic parachute was inoperable because the extraction charge had been removed by the pilot to prevent accidental deployment while the aircraft was stored in a hangar.
Findings
- The primary cause of the accident was the loss of the right wing's upper fabric covering, which led to a total loss of control.
- The detachment of the leading-edge plate was driven by corrosion and adhesive failure, which allowed the plate to move and eventually shear the wing fabric.
- The aircraft had been stored outdoors, exposing the structure to UV radiation and salt air, which likely accelerated the degradation of the materials.
- The safety benefits of the ballistic parachute were nullified because the pilot had previously removed the pyrotechnic extraction charge.