What happened
On 25 June 2001, a Piper PA-23-250, registration G-BAVZ, was conducting a private flight from Biggin Hill to Liverpool. During the flight, while operating in CAVOK conditions, the pilot noted that the right engine began to surge. Although fuel flow readings appeared to be within normal parameters, the pilot suspected a malfunction within the propeller Constant Speed Unit (CSU).
Following this observation, the pilot shut down the right engine. Approximately ten minutes later, the left engine began exhibiting similar surging symptoms. In response to the deteriorating engine performance, the pilot identified a suitable landing site near Chester, Cheshire. The aircraft completed a successful precautionary landing, resulting in no injuries to the two occupants and no damage to the airframe.
The investigation
The investigation was based on the aircraft accident report submitted by the pilot. The inquiry focused on the sequence of engine malfunctions and the operational decisions made during the flight. The investigation established that the engine issues were accompanied by a failure to manage fuel tank selections correctly.
Findings
- The right engine experienced surging, which the pilot initially attributed to a potential fault in the propeller CSU.
- The left engine subsequently developed similar symptoms after the right engine had been deactivated.
- The primary cause of the incident was fuel mismanagement, specifically that the pilot failed to adjust the fuel tank selections at the necessary intervals.