AAIB calls for smoke warning following 777 fire beneath cockpi.
An electrical fire beneath the flightdeck floor of a United Airlines Boeing 777-200
reached a temperature of more than 1,000°C (1.832°F) without generating any fire or smoke warnings for the pilots, says a UK Air Accidents Investigation Branch
The event occurred at London Heathrow airport on 26 February 2007
just after the crew had started the engines, and the fire was
identified when a tug driver told the crew that smoke was coming from
the main equipment centre vent.
The AAIB say the initial cause of the fire was the failure of
contacts in the right generator circuit breaker and right bus tie
breaker, but the root cause of that failure is not known because of the
damage caused by the intense heat.
One recommendation is that a tray must be sited below the power
panels to catch drops of molten metal should a contact fail again,
because this will prevent the drips igniting the insulation blanket
Among other recommendations, however, the AAIB says that the crew
should be warned directly of smoke in the main equipment centre, and
the power panels should be designed to isolate automatically contacts
that are short-circuiting. The US Federal Aviation Administration
are acting on these.
The AAIB notes that, because power panel contacts had previously
failed, the manufacturer was already seeking remedies before the