What happened
On May 17, 1998, at 14:55, a Colomban MC 15 aircraft, registration F-PRJF, was performing a local private flight from the Chambéry-Challes Les Eaux aerodrome. During the takeoff roll on runway 32, the aircraft's right engine suffered a loss of power and subsequently ceased operation.
In response to the engine failure, the pilot attempted an emergency landing in a nearby field. Upon impact with the ground, the landing gear collapsed, causing the aircraft to come to rest on its belly. The aircraft sustained heavy damage, and the pilot sustained one injury.
The investigation
The investigation focused on the mechanical failure of the right engine, a SOLO 210, and the aircraft's airworthiness status. Investigators examined the fuel tanks and found they contained gasoline; no issues regarding fuel supply or carburetion were identified in the failed engine.
It was noted that the aircraft was equipped with two different engine models (a JPX PUL 212 on the left and a SOLO 210 on the right), a modification that had not been reported to the aviation authorities. Additionally, the aircraft's restricted certificate of airworthiness had expired on April 21, 1998. The owner, who is also the manufacturer of the aircraft, had owned the plane for over six years.
Findings
- The primary cause of the engine failure was the loss of a spark plug.
- This failure occurred because an additional spark plug had been installed via a new thread tapped into the cylinder head.
- The aircraft was operating with an expired certificate of airworthiness.
- The installation of mismatched engines was not officially documented with the authorities.