What happened
On January 6, 2003, a Robin DR 400-120, registration F-GGJR, was performing a flight from Chambéry Challes les Eaux toward Melun with a pilot and two passengers. The aircraft had been parked outdoors under snow and ice for several days. Shortly after takeoff from runway 33, the aircraft entered a stall and collided with a hangar located approximately 800 meters from the end of the runway. The impact resulted in three injuries and the destruction of the aircraft.
The investigation
The investigation examined the wreckage, meteorological conditions, and a video recording made by a passenger during the flight. Investigators found that the aircraft's wings were covered in a layer of frost and ice, approximately 1 cm thick on the leading edges. The engine experienced a brief power reduction of 150 RPM approximately 32 seconds after takeoff, followed by a stall warning and a sudden loss of control involving a steep right bank and dive.
Analysis of the aircraft's configuration revealed that the flaps were set to the 60° landing position during takeoff. Furthermore, weight and balance calculations determined that the aircraft was operating at a high mass and an aft center of gravity. The total mass was approximately 900 kg, which, when including the weight of the ice, exceeded the manufacturer's structural limits. The pilot had also failed to perform a precise weight and balance calculation, relying instead on an assumption of being within limits.
Findings
- The aircraft was operating with a degraded aerodynamic profile due to the presence of unremoved ice and frost on the wings.
- The aircraft was in a high-mass, aft-center-of-gravity configuration that exceeded manufacturer limitations.
- The takeoff was performed with flaps in the landing position (60°), which increased drag and hindered climb performance.
- A brief loss of engine power occurred during the initial climb, which, combined with the existing flight conditions, triggered the stall.
- The pilot's flight preparation was insufficient, failing to account for the impact of the ice, the heavy load of luggage, and the necessity of a new fuel stop.