What happened
On April 20, 2014, a Robin DR400-180R, registration F-GEIJ, was performing a glider tow operation at the Mantes-Chérence aerodrome. During the fourth tow of the day, the aircraft began its takeoff roll on runway 12. As the aircraft approached the intersection with runway 04/22, the glider pilot noted that the tow plane had not yet reached rotation speed and subsequently released the tow cable to land.
Following the release, the tow plane pilot continued the takeoff roll, but the aircraft veered longitudinally off the unpaved runway. The aircraft struck a fence and entered a wheat field, where it bounced several times before colliding with trees located approximately 337 meters from the end of the runway. The impact caused the aircraft to catch fire. The pilot managed to exit the wreckage before the fire intensified, sustaining minor injuries.
The investigation
Because the wreckage was destroyed by fire, investigators were unable to examine the engine or determine the specific settings of the flaps and elevator at the time of impact. However, data from the glider's FLARM device indicated that the aircraft had reached a speed of approximately 120 km/h during the takeoff phase, suggesting the aircraft was likely capable of flight.
The investigation also reviewed the pilot's experience and the aircraft's performance. The pilot, an experienced flyer with over 1,000 hours on airplanes, reported no engine issues but felt unable to exceed 80 km/h. The investigation noted that the pilot had not conducted a pre-takeoff briefing for this specific flight.
Findings
- The investigation could not determine the specific reason the aircraft failed to rotate, as the engine was destroyed by fire.
- The pilot continued the takeoff attempt even after the aircraft had left the runway, likely because the aircraft briefly lifted off the ground during the excursion.
- The lack of a pre-takeoff briefing contributed to the incident, as such briefings are essential for preparing for engine failures or the need to abort a takeoff.
- There was sufficient runway remaining (over 300 meters of field) to have stopped the aircraft before hitting the trees.
- The pilot's ability to exit the aircraft was hindered because the canopy became stuck halfway open, though the pilot was able to escape despite the fire.