Backed-Up Sink Cripples 747

It’s often said that aircraft accidents are the result of a series of seemingly innocuous events strung together and the crew of a Qantas Boeing 747 might agree with that. The flight from London to Sydney was 15 minutes from touchdown for a scheduled stop at Bangkok when it lost power from all four engine-driven generators. Backup batteries kept all those displays in front of the pilots glowing through a safe landing but the battery power likely wouldn’t have lasted more than another 45 minutes and that would have knocked out the radios and all of the electronic instruments. “In this case it looks as if it has gone to the last stage of emergency power for communication and navigation,” Dr. Arvind Sinha, director of aerospace at RMIT University in Melbourne, told the Sydney Morning Herald. “After that it comes down to the skill and experience of the crew.” He added that the loss of all four generators is “unheard of” but Murphy can and does find a way, this time through a sink with a clogged drain in the first-class galley. [more] The sink is right over the electrical distribution unit and Boeing engineers evidently considered the potential for leaks when they put it there. A drip tray is installed to catch any overflow from the sink but the tray on this aircraft was cracked. The water (likely loaded with soaps, acids and other electrolytic substances) leaked through the crack and into the power unit, shorting out the whole works. Qantas fixed this airplane and checked all others before letting them in the air again. Qantas spokesman John Borghetti said the crew did as it was trained to do to arrive at a safe outcome and no similar problems were found on the other planes.