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| Damage to the left wing of Qantas A380 |
Air travelers from Auckland to the Big Apple are watching, anticipating that investigators will determine not just what happened to cause the engine to come apart at 6,000 feet, but what the event demonstrates about how the world's largest airliner holds up in such a scenario. So far, the answer appears to be, not well.
I was with Jörg Handwerg, (a Flying Lessons reader) and pilot with Lufthansa, when I first heard the details about what came undone on the A380. Right away, I wondered about that outboard engine. Its been widely reported that after the left inboard engine exploded, the pilots could not change the thrust setting on the outboard which had been set on climb. I'm having some trouble imagining the flight characteristics of a 300-500 ton airplane with this curious combination of engine limitations, but that's not what troubled me. I was thinking about fire.
One engine is roaring full throttle, another is spewing shrapnel, the wing has a gaping hole, possibly including a rupture to a fuel tank. Well, it doesn't take a aeronautical engineer to put those together and conclude there may be a helluva fire hazard there.
Then today, the Australian newspaper Herald Sun publishes a list of follow-on effects of the failure that included
- unable to shutdown number 1 engine using the fire switch
- fuel leak in left wing tank.
Fuel leak? Lack of fire protection?
Kudos to the pilots on the flight deck who brought this leviathan back to the Singapore Changi International airport safely. Kudos to the first responders (balls of steel there) who raced to the scene and tried to extinguish 70,000 pounds of thrust on the runaway number one engine using fire hoses.
The 466 people on board Qantas Flight 32 were well served by these folks. The rest of the traveling public is depending on the investigators to look beyond the starring role of the Rolls Royce engine in this drama. They need to ask tough questions about the whole laundry list of items that failed because of the uncontained engine failure, including those that could challenge the assumptions used in the design of the engine and the airplane.
Investigators, gird your loins. Balls of steel will be required.
8 comments:
EASA Emergency AD published to mandate additional inspections. Regards
Additional inspections of the engine is a good start but that doesn't address the consequent damage to the airplane.
It certainly does appear that there were a number of holes in the systems safety analysis conducted in certifying the airplane. I'd have to ask if this is related to Airbus being a government-held entity and the certifying agencies being arms of the same governments footing much of the bill.
Forgive my conservative thinking Christine, but maybe "Nerves of Steel" is what is required rather than "Balls of Steel"!
Note that the outboard engine was *not* stuck on full thrust - the crew had full control over its thrust settings throughout the flight. The only issue with that engine was that the switch-off after landing failed (as this used a different electrical system from the thrust controls).
Oh, also:
I'd have to ask if this is related to Airbus being a government-held entity and the certifying agencies being arms of the same governments footing much of the bill.
The Australian, Singaporean and Dubai governments (ie the first places where A380s were registered and used by commercial airlines, and hence the places where they are regulated) footed the bill for the A380? Really?
(also EADS is a listed company, with the French state owning a 15% stake and the Spanish state a 6% stake - over 80% of its shares are privately held).
(ie the first places where A380s were registered and used by commercial airlines, and hence the places where they are regulated) I was under the impression that certification would have occured mainly by EASA, as the aircraft was designed and built in Europe.
Current EASA regulations only require containment of a single fan or turbine blade (http://easa.europa.eu/ws_prod/g/doc/Agency_Mesures/Certification_Spec/CS-E%20A2/CS-E_Amendment%202.pdf CS-E 810 a)
Further, on page 2-D-1 the document states "The safety analysis should support the Engine design goals such that there would
not be Major or Hazardous Engine Effects that exceed the required probability of occurrence as a result
of Engine Failure modes" The key phrase here is required probability of occurrence. In the end an uncontained engine failure could produce any number of 'projectiles' following any number of paths and there is a limit to how much redundancy one can build into an (economically viable) aircraft.
While I agree that it will be very interesting to see what can be learned from this accident, and specifically which hidden system interactions come to light, I think one needs to accept that it is impossible to protect the aircraft against all possible consequences of an uncontained engine failure, and that reducing the probability of such a failure could be the most effective strategy.
The outer #1 engine went into Idle speed as part of a failsafe reaction once the controls were severed by the explosion. so I think the 70K lb of thrust was not active. There would have been disaster if 70K of thrust was present when landing. The fireengines sprayed water and the engine stopped easily as it was on Idle mode.
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