'Human ingenuity prevented Qantas crash'

2010-11-19 16:32

Washington - Even in a cockpit jammed with the most advanced computers, sometimes only a human being will do.

Like when your super-sized airliner is climbing thousands of meters over Indonesia and one of its four engines explodes, shooting flames and blasting shrapnel holes in the wing. And then computer warnings of impending failures of systems across the aircraft start flooding onto cockpit screens.

That was the position five pilots found themselves in two weeks ago when their Qantas jetliner suffered an extraordinary engine breakdown that set off a cascade of other events, each of which by itself would have represented a serious safety problem on an ordinary day.

The Airbus A380, which was carrying more than 450 passengers and crew, is on the leading edge of a new generation of smarter, more highly automated airliners, planes so sophisticated they can sometimes even override a pilot to prevent a critical error. Faced with a crisis, however, it was creative thinking, not computer programming, that landed the plane safely.

"These conditions were a step beyond what the airplane was designed for, and it was the pilots who sorted it out so that it resulted in a safe landing," aviation safety consultant John Cox of St Petersburg, Florida, said in an interview on Thursday.

Richard Woodward, a fellow Qantas A380 pilot who has spoken to the pilots and vice-president of the Australian and International Pilots Association, said the number of failures faced by the pilots was unprecedented.

Growing imbalances

"There is probably a one in 100 million chance to have all that go wrong," Woodward said in an interview.

But it did.

Engine pieces sliced electric cables and hydraulic lines in the wing. Would the pilots still be able to fly the seven-story-tall aircraft?

The wing's forward spar, a beam that attaches it to the aircraft, was damaged as well. Also the wing's two fuel tanks were punctured. As fuel leaked out, a growing imbalance was created between the left and right sides of the aircraft, Woodward said.

The electrical power problems prevented the pilots from pumping fuel forward from tanks in the tail. The aircraft became tail heavy.

That may have posed the greatest risk, safety experts said. If the aircraft had become too far out of balance, the Singapore-to-Sydney jetliner would lose lift, stall and crash.

Two extra pilots

And then there was that incredible stream of computer messages, 54 in all, alerting the pilots to system failures or warning of impending failures.

One warned that a ram air turbine, a backup power supply, was about to deploy, although that never happened, Woodward said. The message was especially worrisome because the system deploys only when main power systems are lost. The smaller backup supply is able only to power vital aircraft systems.

That is "the last thing you need in that kind of situation", he said.

As luck would have it, there were two extra pilots, both captains, aboard on November 4. The flight's captain, Richard de Crespigny, was being given his annual check ride, a test of his piloting skills, by another captain. That man was himself being evaluated by a third captain. There were also first and second officers, part of the normal three-pilot team.

In all, the crew had more than 100 years of flying experience.

"The computer can only do what it knows how to do. They don't get creative very well," Cox said. "These extreme catastrophic conditions, very rare as they may be, point to the need for very high quality training and high calibre individuals flying the plane."

Prioritising problems

De Crespigny concentrated on handling the controls, while the others dealt with the computer alarms and made announcements to the giant planeload of passengers, some of whom said they were frantically pointing to flames streaming from the engine. Working flat out, it took 50 minutes for the pilots to work through all the messages.

When pilots receive safety warnings, they are supposed to check the airline's operating manual and implement specific procedures. But with so many warnings, the Qantas pilots had to sort through and prioritise the most serious problems first.

It is likely that for some of the problems there were no procedures, because no airline anticipates so many things going wrong at once, said John Goglia, a former US National Transportation Safety Board member.

Attention since the November 4 incident has focused on the Airbus 380's damaged Rolls Royce engine. As many as half of the 80 engines that power A380s, the world's largest jetliners, may need to be replaced, Qantas CEO Alan Joyce said on Thursday. That raises the possibility of shortages that could delay future deliveries of the superjumbo.

Qantas has grounded its fleet of six A380s.

Designed with redundancy

Actually, Woodward praised the aircraft, saying it was a testament to its strength that it was able to continue to fly relatively well despite all the problems. But he also said it is likely that the design and location of electrical wiring in the wings might be reconsidered.

Airplanes are supposed to be designed with redundancy so that if one part or system fails, there remains another to perform the same function. That did not always happen in this case, safety experts say.

"The circumstances around this accident will certainly cause the regulatory authorities to take a long and hard look at a number of certification issues," said Goglia, the former National Transportation Safety Board member and an expert on aircraft maintenance.

"What we have got to ensure is that systems are separated so that no single point of failure can damage a system completely," Woodward said. "In this situation the wiring in the leading edge of the wing was cut. That lost multiple systems."

However, Michael Barr, who teaches aviation safety at the University of Southern California, said a commercial aircraft cannot be designed with certainty to withstand a spray of shrapnel, which can inflict damage anywhere. The proper focus, he said, should be on determining what caused the engine to fail and fixing that problem.

All the experts were agreed on one point.

"It must have been an exciting time on that flight deck," Barr said dryly. "It's not something you'd ever want to try again."

  • Mr D - 2010-11-19 16:46

    Fantastic well done. What will our SA pilots do, make me think of our 6 Fighter pilot hahaha O my lord say no more

      Ian - 2010-11-19 17:24

      Not a very nice snide remark. Our SAA pilots are trained to just as high standards and always have been.

  • Boerseun - 2010-11-19 19:04

    It wouldbe better if the SAA's affirmative action pilots never get into any planes, after looking at this affair. If they were in charge, well most probably people would have died.

  • Ibo - 2010-11-19 19:21

    this article makes me think the different between someone whose much liked and someone whose not so lucky to be respected or loves by the white media world. Look at the embarrassment of the Qantas crushes and add over that the fact that not a China or African but English Rolls-Royce made these rubbish engines. Imagine that Qantas was SAA or any non worsen nation airline, how the news could be said. If the Engines were made in China how news24 and her allies and the militants here who always looks for ways to ambush South Africa or anyone who don’t looks like them. Look how profesional media source like news24 present the news about the accidents of Qantas; present it without any damage not on Qantas or Rolls-Royce. Look at this latest article they even turn the failure, stupidity and carelessness by both (Qantas & Rolls-Royce) news24 turn these failure to Heroes and Heroines.

  • Collitjies - 2010-11-20 09:31

    Appears that the A380 Airbus is an accident looking for some where to happen, what do you expect, its French even their condoms fail.

  • Fikile - 2010-12-02 12:20

    The Qantas pilot is South African..... got you. SA has of the best, and the most respected pilots in the world, the airlines queue up to employ them. Why are whites so negative about the country, the counties fate is in your hands, so stop making excuses if you want to make a home here or have something called home here, start making a positive difference, it starts with you. Be Positive you can make a difference.

  • Richard - 2010-12-02 19:30

    Years ago, I got a call from a fellow system safety engineer who had been fired from the Airbus community for blowing the whistle about the A380 computers that had been certified on the basis of similarity, rather than flight testing. I wonder what the whole story is.

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