Leaking Galley Drip Tray Leads To Loss Of Electrical Power

Australia's Transport Safety Bureau and Civil Aviation Safety Authority, Boeing and Qantas are all involved in an investigation into an incident Monday, in which a Qantas 747 flying 344 passengers from London to Bangkok lost main electrical power during its descent.

The Australian reports a cracked drip tray below the plane's first-class galley allowed water to drip into a generator control unit. Cabin lighting went out, but cockpit functions continued on battery power to allow pilots to make an otherwise routine landing.

"It happened at 15,000ft, so already descending on approach, and I think the first thought was 'get the aeroplane down', which was quite right," said David Cox, Qantas executive general manager for engineering. "Had they been presented with the challenge with more time in the air, there are other things they could have tried.

"It was just like tipping a glass of water into your stereo," Cox said of the incident. "It is not a good thing for that sort of equipment to have happen to it."

The paper quoted unnamed aviation sources who said the battery backup system, which is supposed to guarantee 30 minutes of operation to critical systems, probably would have lasted more like an hour... but the situation would still have been grave if it happened when the plane was more than an hour from a suitable landing site.

Cox told the paper he expects the incident to prompt an alert to other operators of the plane from Boeing, and possibly regulatory action.

"At the moment, we're out inspecting the fleet and looking to see where that water may have come from, and what steps we need to take to stop that water getting in there again," he said. "Obviously correcting the drip tray is an immediate action but that's a relatively simple thing to do. The bigger concerns are around how the water got there, and how we protect the avionics better."

FMI: www.boeing.com, www.qantas.com