What happened
On July 9, 2004, at 17:40, a Robin DR 300-120, registration F-BSOT, was involved in a ground accident at La Flèche aerodrome during a local flight. The pilot was accompanied by three passengers, including two individuals on their first flight.
While waiting for the passengers to arrive, the pilot performed a pre-flight inspection but intentionally left the pitot tube and static port covers in place, intending to remove them during boarding. After the passengers were seated, the pilot started the engine and took off. Shortly after departure, the pilot noticed that the airspeed indicator, altimeter, and variometer were behaving abnormally, with the airspeed stabilizing around 100 km/h. Realizing the static ports were still obstructed, the pilot returned to the aerodrome to land.
After landing and taxiing back to the parking area, the pilot did not shut down the engine. Instead, the pilot instructed a passenger, seated in the rear left position, to exit the aircraft to remove the covers. The passenger exited the aircraft but could not locate the left-side static port cover. While moving around the left wing to reach the pitot tube, the passenger then attempted to walk around the front of the aircraft to reach the right-side static port. During this maneuver, the passenger's right arm struck the rotating propeller, resulting in one passenger being seriously injured and subsequently undergoing an arm amputation.
The investigation
The investigation focused on the sequence of ground operations and the safety protocols followed during the engine-running period. Investigators examined the pilot's decision-making regarding the pre-flight inspection and the delegation of safety-critical tasks to an untrained individual. The investigation also reviewed the cockpit instrumentation readings that led to the decision to return to the aerodrome.