History of the Flight
On 7 September 2003, a Boeing 757-236, registration G-CPER, operated by an airline, was involved in a serious incident. During the flight, the crew encountered a roll control problem and detected hot oil and electrical burning smells in the cabin. The aircraft landed safely at London Gatwick Airport.
Maintenance Errors
The investigation identified two distinct maintenance errors that contributed to the incident. First, two access panels on the right wing, designated 666AR and 666BR, were not properly secured following maintenance. This led to the roll control issue. Second, the engine oil servicing task was not carried out correctly, resulting in the oil and burning smells.
Access Panels
The access panels were removed during maintenance on the right wing. The procedure for installing them was not followed correctly; the panels were not fastened securely. During flight, the panels detached, affecting the airflow over the wing and causing roll control difficulties.
Engine Oil Servicing
The engine oil servicing task was performed incorrectly. The technician did not follow the prescribed procedures from the Aircraft Maintenance Manual or the maintenance organisation's instructions. This led to oil leakage and the generation of hot oil and electrical burning smells in the cabin.
Injuries and Damage
The report states that there were no injuries to persons. The aircraft sustained damage to the right wing area due to the detached panels and possible oil contamination, but no further details are provided.
Investigation Findings
The Air Accidents Investigation Branch (AAIB) conducted the investigation. The probable cause was explicitly stated as the combination of two separate maintenance errors: the failure to secure two access panels on the right wing and the failure to correctly carry out the engine oil servicing task.
Maintenance Organisation
The incident highlighted deficiencies in the maintenance organisation's quality assurance and supervision. The investigation noted that the certifying technicians did not adequately verify the work, and the procedures for controlling access panels and oil servicing were not followed.
Conclusion
The serious incident was entirely attributable to maintenance errors. No other factors, such as design or environmental conditions, were cited as contributing causes.