Incident Overview
On 1 March 2013, at 0912 UTC, a Boeing 737-377, registration G-CELS, was being prepared for a ferry flight at Stand 25 of London Gatwick Airport. The aircraft had no passengers on board; the crew consisted of six members. During pre-flight checks, smoke was seen emanating from the area of the overhead bin above seat row 1 D, E, F. The crew member reported smoke and sparks. The cabin crew were ordered to leave the aircraft, and the flight crew performed the Quick Reference Handbook drills and declared a MAYDAY before evacuating.
Investigation Findings
The operator's engineering organisation determined that the smoke and sparks resulted from arcing across the pins of an electrical connector previously used to power the No 2 galley unit, which had been removed from the aircraft. Tests confirmed that, even though the circuit breaker for the galley unit was tripped and collared, voltage remained present at the connector pins. The connector was subsequently removed, and the wires were capped and stowed.
Previous Inspection Issues
In 2012, a Line Maintenance Work Request (LMWR) was raised to inspect the operator's fleet, including G-CELS, after a similar event identified the possibility of the redundant galley connector remaining powered despite the circuit breaker being tripped. Analysis of the results showed that for G-CELS and several other aircraft, the LMWR had identified that the connector remained live. However, the system for controlling LMWRs allowed them to be closed without confirmation that the additional work identified had been completed.
Safety Actions Taken
The operator changed the systems used to manage such inspections to ensure that additional work must be completed before the inspection is closed. An additional inspection was carried out on aircraft that the previous LMWR indicated might require further work. One other aircraft was found to have a live No 2 Galley connector. The operator also reviewed its procedure for managing LMWRs and introduced new systems and procedures to ensure that any additional work identified during an LMWR is completed before the LMWR can be closed.
Damage
The incident resulted in minimal damage around the electrical connector.