What happened
On July 4, 2014, a Tecnam P2008, registration F-HDMV, departed from Lognes-Émerainville aerodrome for a local instructional flight. Shortly after takeoff, at an altitude of approximately 50 feet, the instructor noticed a significant drop in engine power. The propeller RPM fell from a nominal climb value of 2,250 to approximately 900 RPM.
As the aircraft was flying over an area with heavy vehicle traffic, the instructor opted not to attempt a landing along the runway centerline. Instead, the instructor initiated a left turn toward a clear area to perform a forced landing. During this maneuver, the left wing made contact with the ground before the aircraft came to a stop on an unpaved surface. The engine ceased running shortly after the aircraft stopped. There were no fatalities or injuries to the instructor or student on board, but the aircraft sustained heavy damage.
The investigation
The BEA examined the Rotax 912 S2 engine and discovered metallic debris within cylinders No. 1 and No. 3. Specifically, the debris prevented the complete closure of the exhaust valve in cylinder No. 1 and damaged both spark plugs. Investigators also found impact marks within the carburetor air duct.
Further inspection revealed that the lower attachment bracket for the carburetor heat air collector was missing, with a fragment of the bracket found near the collector. Chemical analysis confirmed that the debris found in the cylinders matched the composition of the broken bracket.
Regarding the aircraft's manufacturing, investigators determined that the brackets used on this aircraft were thinner (0.8 mm) than the required 1.5 mm specification. This specific aircraft was one of six P2008 models produced with these non-compliant, experimental-grade brackets.
Findings
- The primary cause of the engine power loss was the failure of a non-compliant attachment bracket on the carburetor heat air collector.
- The broken bracket fragment was ingested into the engine through the carburetor air duct, causing mechanical interference in the cylinders.
- The non-compliant brackets were produced for experimental purposes and were inadvertently installed during the serial production of several aircraft.
- The instructor's decision to maneuver away from the runway centerline was a response to the immediate obstacle of vehicle traffic on the approach path.