Many readers will doubtless remember the drama surrounding Qantas Flight 32 in November 2010, when it suffered a catastrophic engine failure shortly after taking off from Singapore en route to Sydney, Australia. Wikipedia reports:
On inspection it was found that a turbine disc in the aircraft's No. 2 Rolls-Royce Trent 900 engine (on the port side nearest the fuselage) had disintegrated. In addition to destruction of the engine, this also caused damage to the nacelle, wing, fuel system, landing gear, flight controls, the controls for engine No. 1 and an undetected fire in the left inner wing fuel tank that eventually self-extinguished.
The damage to the engine was spectacular. (Click either image for a larger view.)
I recently came across Qantas Engineering's newsletter (link is to an Adobe Acrobat document in .PDF format) describing the incident and the repairs that resulted. It's very interesting reading for aircraft enthusiasts, albeit a bit technical. Here's its summary of what was required, at a cost of over $100 million in US dollars at current exchange rates (enough to buy a brand-new Boeing 737, with change left over).
Design
Around 50,000 man hours of design activity was completed with more than 100 drawings created.
Production
- Airbus staff performed approximately 76,000 production man hours;
- Over 170 Airbus staff have worked onsite (on rotation), with nationalities including French, German, Spanish, British, Dutch, Indian, Belgian and American;
- Qantas performed over 11,000 man hours of production work including modifications, preservation tasks and maintenance activity; and
- Airbus staff working on the repair in Singapore had an average of 25 years industry experience.
Systems
- About one-third of the wiring in the left wing was replaced. That’s an approximate length of 6.1 kilometres of wiring compared with 37 kilometres of wiring throughout the aircraft.
Logistics
- Ten 40-tonne trucks carried 18 specifically manufactured jacks from a warehouse in Frankfurt to Hamburg harbour, with the
equipment then transported to Singapore by sea (a journey of one month);
- 1,000 air freight shipments carried 1,500 boxes with a total weight of 150 tonnes of parts and tooling;
- Material was transported from 60 shippers and from 25 different airports to Singapore;
- 630 different part numbers were ordered; and
- 220 tools were ordered with a total weight of 110 tonnes.
Testing
- 250 individual tests were done by the embodiment team during repairs;
- 250 additional tests were done during the ground testing phase (similar to those carried out with a new aircraft off the production line);
- Flight testing comprised: a rejected take-off at 100 knots; a technical acceptance flight; and a flight to measure the performance of the airframe and engines.
- Check sequences during the assessment flight included:
- high ‘G’ manoeuvres to test the tolerance of the airframe;
- individually shutting down each of the four engines and restarting it;
- flying at slow speeds to test antistall systems;
- turning off engine-powered hydraulic systems to ensure that the aircraft remained controllable;
- testing emergency electrical systems; and
- extending the landing gear via the alternate method.
After Nancy-Bird flew home, many Engineering staff were still required in Singapore to complete the job. This included the removal and destruction of three truck loads of unserviceable aircraft parts to prevent re-birthing, returning components to various locations and vendors around the globe, finalisation of contracts, returning the massive amount of legal documentation to Sydney and of course the cleanup and exit of the facility in Singapore.
Statistics:
- 110 tonnes of tools ordered
- 630 different part numbers required
- 150 tonnes of airfreight shipped
- 3.8 miles of wiring replaced
- 11,000 Qantas man hours performed
- 2000 chilli crab consumed
There's much more at the link.
I imagine that last statistic was the most enjoyable part of the entire operation!
Peter
11 comments:
I notice they left off statistics on the beer consumed with the crab.
Interview with the pilots. Fascinating stuff.
https://www.aerosociety.com/news/exclusive-qantas-qf32-flight-from-the-cockpit/
I was wondering why they put so much time and money into the repair.
This is why:
Cost of the Airbus 380: $400 Million
All that design and production work seems odd for a repair. I suspect lots of padding and/or CYA going on to justify all of that. The testing regime seems appropriate, but design? They damn sure are not re-engineering that wing, as that is not allowed under certification rules.
What caused the failure? I guess I'll go read the report.
Back in the late 80's the CG HH65A had the Lycoming LTS-101 engine, turned out there was cracking (sometimes)in the cast power turbine blades, one failed while a helo was taxing out.
I heard the fuselage & tail rotor drive shaft were trashed. Good thing it was still on the ground when that happened.
After that we started doing an dye pen inspection to the power turbine blades every 20 hours.
Some years later they replaced the engine...
I strongly suggest you read the account of this incident, titled QF 32. It makes for stunning, fascinating reading. As with the ditching into the Hudson, so to with this event, in that, all the crew, some, from decades prior to their respective incidents, would seem to have been moulded by circumstances leading up to the time of the events.
Turns out the design work was due to cracks found in the wing structures during the repair work, so they had to figure out how to fix the problem. Not engine failure related. ALL 380's had the mods done, eventually, it seems. Adds about 200lbs of reinforcing to the aircraft.
Yeah, bad things happen when a jet engine eats itself. I'm glad the aircraft survived.
There's an episode of Air Disasters on this showing occasionally on the Smithsonian Channel. Don't remember the details, but the pylons that held the engine had to be redesigned. The pylons were causing the cracks in the wing that Will mentioned.
Root cause?
"On inspection it was found that a turbine disc in the aircraft's No. 2 Rolls-Royce Trent 900 engine (on the port side nearest the fuselage) had disintegrated. In addition to destruction of the engine, this also caused damage to the nacelle, wing, fuel system, landing gear, flight controls, the controls for engine No. 1 and an undetected fire in the left inner wing fuel tank that eventually self-extinguished.[1] The failure was determined to have been caused by the breaking of a stub oil pipe which had been manufactured improperly."
A friend was flying a T-33 out of Ramstein, Germany when, while looking out over the wing at 30,000 feet he suddenly saw a bunch of holes punched in the wing. He looked at the other, saw the same thing, and turned to look at the power instrument, only to see the RPM going quickly to Zero. He landed dead stick at Frankfurt and saw the problem was an uncontained failure. The aircraft was a complete loss.
He said it was rather hairy for a bit. To add insult to injury one of the main gear also collapsed on landing. I can't imagine the pucker factor of such an uncontained failure in that large an aircraft.
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