What happened
On 13 July 2015, a Pipistrel Taurus 503 microlight, registration 34-ABF, departed from Mont-Dauphin Saint-Crépin aerodrome for a local flight. The pilot and one passenger were performing a flight in a glider configuration, having reached an altitude of approximately 1,900 meters and subsequently shut down the engine to glide.
During the flight, the aircraft entered a right-hand turn and transitioned into a spin. An eyewitness, a glider pilot flying nearby, observed the aircraft performing a high nose-down attitude and noted that the aircraft entered a spin that lasted for approximately four rotations. During the descent, the passenger attempted to deploy the emergency parachute by pulling the activation handle; however, the system failed to deploy. The microlight eventually struck trees and the mountainside at an altitude of 1,700 meters. The accident resulted in one fatality and one serious injury.
The investigation
The investigation focused on the aircraft's configuration, the meteorological conditions, and the functionality of the emergency parachute. Investigators examined the wreckage, noting that the engine was in the retracted position and the flaps were extended to a 17-degree landing configuration. The pitch trim was found in a pitch-up position, which was consistent with the weight of the two occupants exceeding 140 kg.
Meteorological analysis revealed strong turbulence, windshear, and significant thermal updrafts/downdrafts caused by the local terrain. Regarding the emergency parachute, investigators found that while the passenger had successfully pulled the handle, the pyrotechnic percussion mechanism had failed to pierce the powder sachets. While factory reassembly errors were considered a possibility, subsequent functional tests of the system could not replicate the failure.
Findings
- The primary cause of the accident was the loss of control of the microlight while operating at low speeds near high terrain.
- The use of a full flaps configuration while attempting to retract the engine in a highly turbulent atmosphere significantly increased aircraft instability.
- The failure of the emergency parachute's pyrotechnic system prevented the deployment of the parachute, contributing to the severity of the injuries.