Boeing Dreamliner Catches Fire In Boston

19061969 writes "The BBC reports that a Boeing 787 Dreamliner caught fire in Boston. Carter Leake, an analyst at BB&T Capital Markets in Virginia, said, 'I don't want to be an alarmist, but onboard fires on airplanes are as bad as it gets.' This represents bad news for Boeing especially after the FAA identified errors in the assembly of fuel line couplings in the Dreamliner."

Lithium ion battery

[Dan East]

It was one of the two large lithium ion battery packs the power the plane when the engines are off. The FCC and pilots were already concerned about the use of lithium ion batteries for this purpose (apparently it's a first), and they issued special regulations just for this plane.

Also the only person on board when this happened was a mechanic (which is probably a good thing at least someone was able to spot the smoke right away).

Re:MSM Strikes Again

[Dupple]

From TFA

"The fire started after a battery in the jet's auxiliary power system overheated."

http://www.bbc.co.uk/news/business-20942484 [bbc.co.uk]

Re:MSM Strikes Again

[X0563511]

Totally unqualified "educated" guess: crew left the APU on even though it's supposed to be off after the engines are up to speed?

From what simulation and speaking with pilots I've gathered, usually you are "supposed" to turn the APU off after engine starts, though usually this is not done as it consumes a tiny fraction of fuel and gives you some wiggle room in the event of an engine failure.

Re:Lithium ion battery

[DieByWire]

But if it was the ground power battery pack that powers the plane when the engines are off, how likely would it have started while flying?

The battery in question doesn't power the aircraft. It's used to power the control circuitry and starter of the auxilary power unit (APU). The APU is a small turbine engine used to generate electrical power and high pressure bleed air for engine starting, or if additional electrical power is needed in flight ( follwing a generator failure, for example.)

I can't speak specifically to the 787, but APU batteries are typically always connected and kept charged in case you need to start the APU without any other source of power. I would assume it can be remotely disconnected as it can be on other aircraft, but once the battery is on fire electrically isolating it is not going to solve your woes.

An inflight fire, especially in an aircraft that could be three hours from shore, is a scary, scary thing.

Re:Titanic

[bigdanmoody]

Indeed, as a former aircraft mechanic, I know that all of the planes that I've worked on have taken fire safety very seriously. The Dash-8's that I've worked on have their batteries placed outside of the pressure vessel. Although I have not personally worked on a plane that uses Li-Ion batteries like the 787 does, my understanding is that aircraft that do use these batteries have numerous warning and safety features to prevent thermal runaway, which sounds like what happened here. Based on the very limited information in TFA, I hypothesize that if the flight crew had been on board, they would have noticed a battery overheat condition and could have taken appropriate action well before a fire broke out.

Re:Lithium ion battery

[slinches]

What you stated is generally true, but the 787 is somewhat of a special case. It uses a no-bleed [boeing.com] APU system which replaces most of the traditionally bleed-driven systems (e.g. engine start, cabin air and wing anti-icing) with electrical equivalents and probably needs a larger set of batteries and higher current (and/or voltage) wiring.

Another One Today

[MichaelJ]

Another Dreamliner just got a fuel leak and dumped a good mess all over a taxiway at Logan until the engine was shut down. Not a good week for 787s in Boston.