What happened
On the evening of Monday, October 4, a Safari BI GT 503 microlight departed from the Millau airfield for a local flight. During the initial stages of the flight, the aircraft was observed flying beneath the cloud base. By approximately 17:00, the aircraft was seen at a much lower altitude, roughly fifteen meters above the ground.
During a subsequent pass, witnesses observed the aircraft performing acrobatic maneuvers within the cloud layer. Following these maneuvers, the aircraft entered an uncontrolled auto-rotation, characterized by a steep nose-down attitude, a heavy right bank, and rapid yawing motions. The aircraft struck the ground with significant force, resulting in two fatalities and the total destruction of the aircraft.
The investigation
The investigation focused on the structural integrity of the aircraft and the flight maneuvers performed prior to the impact. Examination of the wreckage revealed that the tip of the right wing had broken off before the aircraft hit the ground. Analysis of the remaining wing structure indicated that the airframe had been subjected to multiple instances of significant positive and negative vertical load factors.
Findings
- The primary cause of the structural failure was the right wing tip breaking due to excessive positive vertical load factors.
- The aircraft was performing maneuvers that exceeded its structural design limits.
- According to the manufacturer's documentation, acrobatic maneuvers are strictly prohibited for this specific aircraft model.