What happened
On 23 February 2010, an Embraer 195, registration G-FBEE, was performing a non-revenue ferry flight from Jersey Airport to Birmingham International Airport. During the flight, the crew noted the aircraft felt slightly noisy, though engine vibrations appeared to be within normal limits. Upon arrival at Birmingham, the crew was alerted by another aircraft that they should inspect the right engine. A subsequent inspection revealed that both engine fan cowl doors were missing. The detached components were later recovered from the runway at Jersey Airport.
The investigation
The investigation established that the aircraft had arrived in Jersey the previous evening following a hydraulic leak in the No 2 engine pylon. Maintenance was required to inspect the engine-driven pump and hydraulic filters. The investigation found that a technician had opened the engine cowlings to perform the pump inspection but was interrupted by a telephone call before the cowl latches could be secured.
During the subsequent shifts, several opportunities to rectify the unlatched cowls were missed. One technician observed the unlatched doors but assumed further access was needed for other tasks; another technician completed the filter check and assumed the previous work had been properly closed out. Furthermore, the commander's pre-flight walk-round inspection did not identify the unfastened latches, as the checklist did not explicitly require checking the security of engine cowls.
Findings
- The primary cause of the incident was the failure to secure the engine cowl latches due to technician distraction.
- A verbal handover between maintenance staff failed to communicate that the cowl latches remained unfastened.
- The maintenance task was not broken down into discrete steps in the technical log, leading to incomplete work being passed between shifts.
- The pilot's pre-flight walk-round checklist lacked a specific requirement to verify the security of engine cowl fasteners.