What happened
On September 15, 2011, a student pilot was conducting a solo navigation flight as part of a CPL/IR H training program. While taxiing in ground effect toward the runway at Angoulême-Brie-Champniers, the pilot prepared to turn right to align with runway 10. During this maneuver, the Schweizer 269 C experienced a sudden loss of engine power.
The pilot was flying at an altitude of approximately 1.5 meters when the power loss occurred. Although the pilot immediately initiated emergency procedures, the aircraft struck the ground heavily and bounced. The pilot managed to force the helicopter back down to the surface before completing the shutdown sequence. The aircraft came to a rest on the taxiway. A maintenance technician nearby observed the engine RPM drop and the subsequent hard impact, while air traffic control reported seeing white smoke emanating from the rear of the aircraft just before it reached the runway alignment.
The investigation
The investigation focused on the mechanical condition of the engine and the pilot's response to the emergency. Physical inspection of the Schweizer 269 C, registration F-GLJF, revealed damage to the tail rotor blades and a buckled rear skid strut.
Technical examination of the Lycoming HIO-360-D1A engine, which had only 160 total operating hours since being factory-rebuilt, revealed significant wear on the intake and exhaust valves under the valve keys. Additionally, the exhaust valve guides were found to be out of tolerance and showed signs of seizing. Investigators also noted that the aircraft's center of gravity was shifted toward the rear during single-pilot operations, resulting in a more pronounced pitch-up attitude.
Findings
- The primary cause of the accident was the imprecise application of emergency procedures by the student pilot following the power loss.
- The engine power loss was caused by premature engine wear that had not been detected during scheduled maintenance inspections.
- The pilot's limited experience and the element of surprise contributed to an inability to fully control the rate of descent.
- The aircraft's rearward center of gravity during solo flight increased the pitch-up attitude, which the pilot identified as a factor in the impact.