What happened
On March 5, 2000, a RANS S-6S Coyotte II, registration CS-UGR, departed from Vilamoura aerodrome at 11:35 UTC for a local sightseeing flight near Salir. The pilot was flying under Visual Flight Rules (VFR) to observe an off-road competition taking place in the area.
Shortly after takeoff, air traffic control at Faro Airport lost radar identification of the aircraft. Witnesses on the ground, part of a medical support team for the competition, observed the aircraft flying at a very low altitude and low speed, performing circles. They noted the aircraft was being buffeted by the wind, causing it to fly sideways. Suddenly, the aircraft''s nose pitched down, and it plunged into an artificial irrigation lagoon. The impact was violent, resulting in one fatality (the pilot) and one serious injury (the passenger). The aircraft was destroyed.
The investigation
The GPIAAF investigation revealed several significant irregularities regarding the aircraft's airworthiness and documentation. While the aircraft was registered as an ultralight, investigators found that the installation of a different engine—a Rotax 912 UL MK-TW instead of the originally registered Rotax 582—had substantially altered the aircraft's performance and weight.
Crucially, there was no weight and balance report (weighing certificate) available for the aircraft following this engine change. Furthermore, the investigation found that maintenance records for the installed engine and propeller were non-existent, and the aircraft's registration as an ultralight had exempted it from certain technical inspections that would have otherwise identified these unauthorized modifications. The investigation also noted that the aircraft was carrying two occupants despite being registered for a single occupant.
Findings
- The pilot was unaware of the aircraft's actual weight and center of gravity following the engine replacement.
- The engine had been improperly regulated due to a failure to follow the required Rotax maintenance procedures.
- The pilot's flight pattern, involving low-speed circling to observe the competition, likely led to a loss of lift that was unrecoverable at such a low altitude.
- The aircraft was operating below the 100-meter minimum altitude limit prescribed for ultralight operations.