Flight Sequence
The pilot departed from Cannes Mandelieu runway 17 for local circuits. While on downwind, the controller advised of two preceding aircraft and instructed an extended downwind. During the long base leg, the pilot reduced power and began descent. Turning final, he attempted to increase power but engine rpm did not respond. He selected the main fuel tank and operated the power control repeatedly without effect. He declared an engine failure, spotted an area clear of houses, turned right, and executed a forced landing. During landing, the aircraft collided with the metal frame of a greenhouse covered with vegetation.
Pilot and Aircraft Information
The pilot held a PPL(A) since 1996, with 367 total hours (313 on type) and one hour in the previous three months on type. He calculated about three hours of fuel remaining before the flight; the right tank had very little fuel, left tank about 30 liters, and the rest in the main tank. He departed on the left tank. He did not use carburetor heat. The aircraft: Robin DR 400-180, registration F-GMMN, operated by a club.
Examination
An on-site examination of the wreckage found propeller damage consistent with low or no engine power. The fuel selector was on the main tank at rescue arrival. The left tank was destroyed with fuel spilled. Fuel was visible in the main and right tanks but quantity undetermined. A post-accident examination of the engine was planned, but club personnel used cutting tools near the wreckage, starting a vegetation fire that destroyed the wreckage. The engine was later removed and examined in a workshop; the fire damage limited the examination, and the cause of power reduction could not be determined.
A 100-hour inspection had been performed two days before the accident. Before that inspection, the club had noted engine problems including vibrations. Additional work included replacing the lower crankcase, carburetor, magnetos, and magneto harness. Ground tests after the inspection were satisfactory, and a 25-minute test flight reported no anomalies. The aircraft had flown 6 hours 29 minutes before the accident flight.
Engine Data
The aircraft was equipped with a Safety Plane data recorder. Data showed engine rpm decreased shortly before descent to 800 rpm and did not increase thereafter until the end of recording.
Conclusion
The examinations could not determine the cause of engine power reduction due to fire damage. The pilot selected a clear area for forced landing but did not detect the metal greenhouse covered by vegetation.