What happened
On 23 September 2021, a Partenavia P68, registration F-HIRD, was conducting a marine wildlife survey off the south-east coast of Ireland. The aircraft, operated by Action Communication, departed from Waterford Airport carrying a pilot and three task specialists. While performing survey lines at low altitude, the right engine suddenly stopped.
In an attempt to manage the situation, the pilot initiated a return to Waterford Airport. During this phase, the left engine began experiencing repeated, significant power losses. As the aircraft approached the shoreline, the left engine lost power entirely, forcing the pilot to execute an emergency landing on a beach near Carnsore Point, Co. Wexford. The impact with the shale surface caused significant structural damage to the forward cabin. The pilot and one task specialist sustained serious injuries, while the remaining two specialists suffered minor injuries.
The investigation
The AAIU examined the wreckage and analyzed flight data to determine why both engines failed during the same flight. Investigators looked into the fuel system, including the fuel selector panel and the crossfeed pipework. The investigation also reviewed the aircraft's maintenance records and the limitations outlined in the Aircraft Flight Manual (AFM).
Findings
- The investigation determined that both engines were operating while the fuel levels were at or below one-quarter of the tank capacity.
- The right engine failure was likely caused by a fuel supply interruption.
- The left engine's power fluctuations were likely triggered by the pilot manipulating the fuel selectors to crossfeed fuel, which may have disrupted the supply due to suspected damage in the crossfeed pipework.
- The fuel selector panel configuration was found to be non-intuitive and potentially misleading.
- The Aircraft Flight Manual lacked clear guidance regarding the risks of operating with fuel levels below one-quarter capacity.
- The aircraft was found to have an invalid Certificate of Airworthiness due to the installation of unapproved auxiliary fuel pumps and a tachometer.
Safety action
Following the investigation, the Type Certificate Holder was advised to provide clearer guidance in flight documentation regarding scenarios that could lead to fuel interruptions. Additionally, the operator updated its Standard Operating Procedures to increase safety margins during flight operations.