Accident
On 23 September 2021, a twin-engine Partenavia P.68 Victor departed Waterford Airport (EIWF) at 11:08 hrs with one pilot and three Task Specialists on board. The specialists, part of an environmental research team, were conducting aerial surveys of marine wildlife off the coast of Ireland. The aircraft seating comprised two rows of two seats and a rear bench seat; the front right seat was occupied by a Task Specialist, with the other two behind, and the rear bench empty.
The flight plan involved flying 16 pre-defined survey lines at approximately 250–300 ft altitude and 100 knots, each line about 45 km long and spaced 4 km apart. After completing the planned lines in about 4 hours 30 minutes, the pilot and specialists discussed extending the flight. Assessing remaining fuel, the pilot decided two additional survey lines were feasible while preserving reserves.
Sequence of Events
Shortly after starting the second extra line, the right engine stopped. The aircraft was travelling at about 105 knots and 300 ft. Recorded data showed a climb to approximately 500 ft. The pilot reported slower-than-expected climb on the left engine alone. At about 500 ft while climbing, the left engine experienced a significant power loss but did not stop completely. Specialists later reported the aircraft dropped height and turned left. The left engine power recovered but then recurred repeatedly: climbing slightly, losing power, descending, and regaining power upon descent. The pilot headed directly toward land. As the aircraft neared the shore, the left engine lost power again. The pilot banked left and executed a forced landing on a beach, where the nose impacted loose shale.
Injuries and Damage
The aircraft sustained significant structural damage to the forward cabin area. The three Task Specialists exited through the left door; the pilot exited through the shattered windscreen. On the beach, the left engine ran briefly at what the pilot described as full power, then the pilot pulled the fuel mixture lever to shut it down. Two Coastguard helicopters attended. The pilot and the front right Task Specialist sustained serious injuries and were airlifted to hospital. The other two Task Specialists sustained minor injuries and were taken by road ambulance.
Probable Cause
The official investigation determined the probable cause to be separate interruptions to the fuel supply of each engine, while operating at or below a quarter of the aircraft’s fuel tank capacity, ultimately resulting in a forced landing. Contributory factors included a lack of clarity in the aircraft Flight Manual limitations section regarding operations at less than ¼ tank fuel, and the configuration of the fuel selector panel being potentially misleading and its operation not intuitive.