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December 6, 2010 12:37 PM   Subscribe

On Friday, the Australian Transport Safety Bureau released their preliminary report regarding the Qantas Flight 32 in-flight engine failure.

A summary of the report reveals that the likely cause of the accident was a poorly machine counterbore on an oil "stub pipe", causing an oil leak and subsequent engine fire that caused a failure of the intermediate pressure turbine. This Wikipedia article on turbofans provides some excellent cutaway diagrams on engine layouts.

Qantas and Rolls Royce, the engine manufacturer, have both issued statements regarding the accident. What makes this particular incident noteworthy (as explained in this NPR piece, which includes a snippet of the pilot's statement to the passengers) is the fact that the combined experience of the pilots and pilot observers in the cockpit likely saved the lives of everyone on board. There are some significant parallels between this accident and United Flight 232 - both planes suffered multiple system failures due to engine shrapnel entering the aircraft, and both were aided by extra pilots in the airplane.

The ATSB maintains a rolling ten-year accident occurrence report for Australian aviation.
posted by backseatpilot (30 comments total) 11 users marked this as a favorite

 
God, this is even scarier than I had first realized:
• Manual braking was continued and the airplane stopped about 150 meters before the runway end.
• After some confusion which of the VHF radios remained available the FO contacted fire services who requested engine #1 to be shut down. The crew replied engine #1 was already shut down but was advised that the engine continued to run. The crew recycled the engine #1 master switch, but the engine continued to run. The crew used the emergency shut off switch and fire extinguisher bottles, but the engine continued to run. The fire commander advised there was fuel leaking from the left hand wing, the FO advised of the hot brakes and requested fire retardant foam to be applied over that fuel.
• The first passenger disembarked through the #2 main deck forward door 55 minutes after landing, the last passenger disembarked about 1 hour later.
• The crew was advised by the fire commander that 4 tyres of the left body gear had deflated. Further attempts to shut engine #1 down were without success, operator advice to activate a number of circuit breakers in the electronic bay also remained unsuccessful. Attempts were made to re-arrange the fuel supply in order to starve engine #1, however due to lack of electrical power that was not possible. Finally the decision was made to drown the engine with fire fighting foam. The engine finally stopped about 127 minutes after landing.
Eek.
posted by Plutor at 12:43 PM on December 6, 2010 [6 favorites]


A bit of video, including the pilot's announcement. I'm always impressed by calm, methodical responses to potentially deadly situations and hope that if push came to shove, I'd be able to breathe and think about the next thing that needed to be done.
posted by Burhanistan at 12:45 PM on December 6, 2010


Every now and the I'll hear someone refer to airline pilots as "glorified bus drivers" or some such. I've never seen a bus driver attempt to change his own alternator while driving 500 MPH at 30,000 feet.
posted by bondcliff at 12:48 PM on December 6, 2010 [12 favorites]


A bus driver has a better pension than an airline pilot.
posted by exogenous at 12:51 PM on December 6, 2010 [3 favorites]


Some interesting information on engine design:

-Combustion gases exit the combustion chamber at several thousand degrees Celsius.
-Turbine blades and discs are usually made of nickel alloys. They're designed to withstand the combustion gas temperatures, and nickel alloys are good for this application because they've got the right combination of ductility, heat resistance, and resistance to creep.
-Unfortunately, nickel alloys strength tends to decrease rather dramatically as the temperature increases - hence why a fire in the turbine stages tends to be Bad News.
-Turbine blades are usually designed with channels in them in order to deliver cooling air.
-The blades are not machined, per se, more like grown. Modern blades are laid up with molten material and are actually each a single crystal.
-Turbine blades experience centripetal accelerations in the order of 10,000 to 100,000 g. Small imperfections tend to blow up (pardon the pun) very quickly at those forces.
posted by backseatpilot at 1:04 PM on December 6, 2010 [5 favorites]


Lots more scary images and initial analysis here.
posted by marvin at 1:10 PM on December 6, 2010


Eponysterical?
posted by sveskemus at 1:33 PM on December 6, 2010


Those Quantas pilots had a really good reason to keep the plane flying and to land safely: to maintain Quantas' record of having no fatal (jet) accidents (youtube link).
posted by vespabelle at 1:39 PM on December 6, 2010


The engine finally stopped about 127 minutes after landing.

The engine that would not DIE!!!!
posted by Jimbob at 2:18 PM on December 6, 2010


That oil pipe stub is pretty darn small. Interesting failure, and interesting consequences.

Thanks for the short summary, Plutor. The the AV Herald summary is a good read, too.
posted by Xoebe at 2:20 PM on December 6, 2010


> The engine that would not DIE!!!!

Some part of the engine can be heard spinning at full speed well after the Garuda Airlines crash in 2007.
posted by Burhanistan at 2:22 PM on December 6, 2010


The Australian ABC has a podcast on the engine failure and what has been happening at Qantas.
posted by sien at 2:25 PM on December 6, 2010 [1 favorite]


Qantas is threatening to sue Rolls Royce over the incident:

The airline had "filed a statement of claim and been granted an injunction by the Federal Court of Australia which will ensure that the company can pursue legal action against Rolls-Royce in Australia... if a commercial settlement is not possible," the airline said.
posted by UbuRoivas at 2:43 PM on December 6, 2010


Some other information on QF32 and the A380's redundant (yellow/green) hydraulic systems, including a video. This image being informative on which systems control what flight surfaces. In this incident, the green hydraulic system was compromised and the plane had to fly using the yellow system.
posted by SirOmega at 3:06 PM on December 6, 2010


"Some part of the engine can be heard spinning at full speed"

Maybe the little gas turbine auxiliary power unit at the tail of the plane...
posted by marvin at 3:17 PM on December 6, 2010 [1 favorite]


I wonder if that engine was burning hydraulic fluid rather than fuel after a while.
posted by jamjam at 3:32 PM on December 6, 2010


(derail)
after this post and the previous one about the xplanes, i am eagerly awaiting a discussion or post on today's concorde accident ruling -- i had no idea. will be googling some now.
posted by 3mendo at 3:40 PM on December 6, 2010


How good is the Australian Transport Safety Bureau? Everyone should be proud of the work of these guys. Yay government.
posted by jjderooy at 4:33 PM on December 6, 2010


Speaking of engines that won't die, check out this incident at Atlantic City from a few years back.
posted by exogenous at 5:36 PM on December 6, 2010 [1 favorite]


The BBC recently made a programme with Rolls Royce, called 'How to Build A Jumbo Jet Engine'. As to the likelihood of whether it has made it's way onto a popular video website, I couldn't possibly comment.

-Turbine blades and discs are usually made of nickel alloys. They're designed to withstand the combustion gas temperatures, and nickel alloys are good for this application because they've got the right combination of ductility, heat resistance, and resistance to creep.

The turbofans operate in air three hundred degrees above the melting point of the alloy. The whole object, which as you say is a single crystal, is machined to within an accuracy of 7 microns, and can withstand a force equivalent to supporting an 18 ton mass. Hypothetically, were the programme to be split into four approximately equivalent sections, this bit would be about five minutes into the second section.
posted by Marlinspike at 5:59 PM on December 6, 2010 [2 favorites]


First time I've heard an English speaking pilot who wasn't doing the Chuck Yeager voice. Thank god.
posted by gjc at 7:56 PM on December 6, 2010


A bus driver has a better pension than an airline pilot.

Not in Australia.
posted by pompomtom at 8:10 PM on December 6, 2010


They're totally different career streams, anyway.

RAAF pilot > regular airline pilot > 747 pilot > retirement into unlimited luxury.

Highschool dropout > McDonalds > drug abuse > jail > taxi driver > bus driver > drug abuse > jail.
posted by UbuRoivas at 8:47 PM on December 6, 2010 [1 favorite]


(I'm pretty sure you can do taxi driving and drug abuse as a double degree...)
posted by pompomtom at 9:51 PM on December 6, 2010 [1 favorite]


(or just do drugs & abuse taxi drivers)
posted by UbuRoivas at 10:20 PM on December 6, 2010


The crew replied engine #1 was already shut down but was advised that the engine continued to run.

I've had this happen to me once too...except in a Honda Civic, not a passenger jet.
posted by robotot at 1:32 AM on December 7, 2010


Plutor quoted: "The first passenger disembarked through the #2 main deck forward door 55 minutes after landing, the last passenger disembarked about 1 hour later"

The reason was, inside the plane was safe; outside the plane were hot brakes, leaking fuel and an engine that would not shut down, so:
"After assessing the checklists the crew decided the safest course of action would be to disembark the passengers through the right hand doors via stairs. A single door was elected so that the passengers could be counted and the other doors remained available should a rapid evacuation via slides become necessary."

What is impressive is how rugged this plane is: after an engine exploded, ripping a hole in crucial sections of the wing, disabling several features necessary to land (reverse thrust, air brakes, part of the flaps mechanism, control over 1 of the remaining engines), the plane still continued flying for 100 mins and landed safely with plenty of runway to spare...

The surprising thing: Cockpit voice recorder is only 2 hours - which was completely overwritten when the plane was on the ground. And the crew continued using autopilot on the approach to the runway instead of manual control... (not that there is much difference on a fly-by-wire, computer controlled plane)
posted by nielm at 3:49 AM on December 7, 2010


Every now and the I'll hear someone refer to airline pilots as "glorified bus drivers" or some such.

My late father-in-law was a Qantas pilot (after Australian Airlines was absorbed). He always said he was a bus driver. No glorified about it. He'd been a pilot in the war (saved by his appendix and a penicillin allergy) and after they'd trained with him, the young blokes apparently always said there could be no greater terror in their future, so they could cope with anything.
posted by hawthorne at 7:37 AM on December 7, 2010


Two weeks ago we toured a regional airport's fire station. Sorry, the ARFF: "Airport Rescue and Fire-Fighting." So you don't think I am burying the lede: just four dudes per shift.

They have three big trucks, each of which is operated by a single person. There's a boom where one nozzle is mouted for use high up, and another "chin-mounted" nozzle that is joystick-controlled or can be set to automatically sweep back and forth. It carries like 13 tons of water and various retardant chemicals.

They explained that their job is to control fires around the plane, and agreed that for the most part either you will survive the crash or not. So the great speed at which a thin metal tube (i.e., the plane) burns means that most often they'll just be damping down or preventing fire aroudn the plane while the crew manages the passengers -- and only sometime waiting for the nearest town to send several trucks to help hose down the wreckage.

They also agreed that often the safest place for passengers is inside the plane: if there's no fire, and it's winter, and the buses haven't shown up to drive everyone to the terminal, why get them all out on the runway?

Nice guys, but very realistic.

Also, riding around with the truck lights on at sunset was the BEST field trip ever. I even passed on sliding down the pole because I was still enjoying the buzz of the truck ride.
posted by wenestvedt at 8:30 AM on December 7, 2010


(or just do drugs & abuse taxi drivers)

Wait... that's a career now? Woohoo!
posted by pompomtom at 5:08 PM on December 8, 2010


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