Incident Overview
On Thursday, 15 September 2011, at approximately 10:15 local time, a Schweizer 269 C helicopter registered as F-GLJF was involved in an accident at the Angoulême-Brie-Champniers aerodrome. The aircraft was operated by an approved training organization (FTO) during a solo navigation session for a student pilot pursuing an integrated CPL/IR H license.
Sequence of Events
The student pilot departed the parking area and transitioned into ground effect while moving toward runway 10. As the helicopter prepared to turn right for alignment, the engine lost power. The aircraft touched the ground twice before coming to rest on the taxiway. The pilot reported that they were hovering at approximately 1.5 meters when the power loss occurred. Despite immediately applying emergency procedures, the helicopter struck the ground hard and rebounded. The pilot then forced the aircraft to the ground and completed the shutdown sequence. Factors contributing to the difficulty in controlling the descent rate included the student's limited experience and the element of surprise.
Witness Accounts and Damage
A maintenance technician working on a nearby helicopter heard the engine RPM decrease and observed the F-GLJF striking the taxiway hard. From the control tower, a controller observed white smoke escaping from the rear of the helicopter just before it aligned. Visual inspection revealed that the rear crossbar of the skid landing gear was scorched and the anti-torque rotor blades were damaged.
Technical Investigation
Technical examination of the Lycoming HIO-360-D1A engine, which had been factory-rebuilt and installed in June 2011, identified significant wear on the intake and exhaust valves below the locking tabs. This type of damage is typically indicative of engine overspeeding. Additionally, the exhaust valve guides were found to be out of tolerance with signs of seizure. The engine had accumulated 160 hours of operation since installation, including 20 hours in August by the owner. Scheduled maintenance visits had not detected these anomalies.
Pilot Background and Contributing Factors
The student pilot had logged 47 hours on type since 6 May 2011, with 14 hours flown solo. The instructor noted that the student's progression was normal and that they had previously practiced engine failure exercises in ground effect together. The instructor attributed the specific damage to the helicopter's significant nose-up attitude during the power failure, which is influenced by the center of gravity shift when operating with a single pilot aboard.