History of Flight
The flight, operated by an Airbus A330-243 (registration G-TCCF), departed from Frankfurt, Germany, bound for Cancun, Mexico. At approximately 1620 UTC, while approaching position N5500.0 W02000.0, the crew was served coffee in cups without lids. The commander, who was pilot monitoring, placed the coffee on his tray table. The cup was knocked over; most of the liquid fell onto his lap and a small amount spilled onto the commander's audio control panel (ACP1).
Sequence of Events
The coffee on the centre console was quickly dried but caused immediate malfunction of ACP1, affecting VHF transmissions and public address announcements. The crew attempted to isolate ACP1 but were unable to do so from the flight deck. At approximately 1700 UTC, ACP1 became very hot and failed, and an electrical burning smell was present in the cockpit. At about 1720 UTC, approaching N5600.0 W03000.0, the co-pilot's audio control panel (ACP2) also became hot enough to melt one of its buttons and failed. A small amount of smoke was observed coming from ACP1. The commander decided to divert to Shannon, Republic of Ireland. During the diversion, the flight crew alternately used supplementary oxygen, with one pilot on oxygen at all times.
The failures caused significant communication difficulties. The commander could not receive or transmit and could only hear transmissions through the co-pilot's speaker. There was no interphone between the pilots. The aircraft diverted to Shannon without further incident. The smoke stopped and though there was a residual burning smell, the fumes did not result in injuries.
Engineering Action
ACPs 1 and 2 were removed and examined by the vendor. The strip report for ACP1 confirmed component failures attributed to liquid contamination. The strip report for ACP2 listed failed components but did not offer potential causes for those failures. The area below the centre console was inspected; no other areas were found affected by liquid contamination.
Analysis
The strip report indicated that the failure of ACP1 and the resulting smoke and fumes were due to electrical shorting caused by liquid contamination. The reason for the failure of ACP2 was unclear from the strip report. The aircraft manufacturer recommends using cup holders; the cups used by the operator on this route were smaller and more difficult to grasp, discouraging use of the cup holder despite policy. The fold-out table in the A330 is vulnerable to items being knocked over. A properly secured lid may have reduced the amount of liquid spilled.
Conclusion
A spillage of coffee onto the centre console led to the failure of ACP1 and ACP2, resulting in communication difficulties for the flight crew. The resulting electrical burning smell and smoke in the cockpit necessitated a diversion to Shannon Airport.
Safety Actions
The operator changed procedure to ensure cup lids are provided on all routes and reminded cabin crew of the requirement to use them. A flight crew notice was issued reminding pilots to be careful with liquids. The operator also raised an action to source and supply appropriately sized cups for the aircraft's cup holders.