What happened
On Sunday, March 25, 2001, at 12:30, a Robin DR 400-180, registration F-BVDA, was performing its second glider tow of the morning near Vinon-sur-Verdon. While climbing at an altitude of 2,500 feet, the pilot observed the low fuel pressure warning light illuminate, followed by a loss of engine power and a subsequent engine failure.
The pilot released the glider and attempted to diagnose the issue. Unable to identify the source of the failure and unable to return to the airfield, the pilot executed a forced landing in the dry bed of a nearby river. Upon impact with the ground, the aircraft was rapidly decelerated by large pebbles, which caused the destruction of the nose wheel and the right main landing gear. The pilot successfully evacuated the aircraft after shutting down the engine.
The investigation
The investigation focused on the fuel system configuration and the sequence of events leading to the engine failure. Investigators found that the fuel selector valve was set to the "Front Left" position, and this specific tank was empty. In contrast, the "Rear" tank contained 100 liters of fuel, and the "Front Right" tank contained 10 liters.
Evidence revealed that during the previous day's operations, a different tow pilot had noticed a low-level warning in the rear tank and switched to the front left tank before landing. After refueling the rear tank, that pilot parked the aircraft without resetting the selector to the "Rear" position.
Findings
- The engine failure was caused by fuel exhaustion in the active tank due to the fuel selector being left on the incorrect setting.
- The pilot's pre-flight inspection was performed too quickly and failed to verify the position of the fuel selector valve.
- The pilot relied on an assumption that local procedures—which required all pilots to leave the selector on the "Rear" position—were being strictly followed by all users of the aircraft.
- The pilot's reliance on the perceived compliance of others contributed to the oversight during the pre-flight check.