Fear Of Flying
By Bernard LaganFebruary 16, 2012
As Qantas manoeuvres around passengers’ concerns about its Airbus A380, aviation experts weigh in on the design of the world’s biggest commercial aircraft and the system designed to detect problems.
The wings are cracked? Another design fault? Is the world's largest passenger jet, the Airbus A380 really safe? They're understandable questions if, like most flyers, you're largely ignorant of modern aircraft systems.
We are, after all, talking about the same model of aircraft as the Qantas plane that brushed disaster when an engine exploded and speared fiery metal through a wing 15 months ago, just after take-off from Singapore's Changi Airport.
Cracked wings and an engine explosion are not events that any airline that has acquired 12 of the world's largest passenger jets wants to see or hear about its new aircraft. And especially not when you're Qantas and you've made the 484-seat A380 the international totem for your long-haul future.
Qantas was the world's third airline, just behind Singapore Airlines and Emirates, to acquire the A380, but it has been the earliest to encounter the airliner's design faults.
The first — the flawed manufacture of a tiny oil-feed tube deep inside the aircraft's Rolls-Royce engines — caused the near catastrophic uncontained engine explosion and made international headlines for the plane, Qantas, and the man who got it down safely, Captain Richard de Crespigny.
The second arose out of the first; miniscule cracks inside the wings of the plane that de Crespigny saved were discovered in January durng its on-going repair operation in Singapore.
Alarm spread when an order for inspections uncovered similar cracks on nearly all of the world's 20 most-used A380s - the earliest airframes, which had made between 1,300 and 1,800 flights. On Feb. 9, those discoveries led to orders for mandatory checks on all 68 A380s flying.
The results have yet to come in, but Joanna Malinowska, a Sydney hypnotherapist who treats those with a fear of flying, is certain those with a disposition to such phobias will be more reluctant to board the A380. "Of course," she says. "Would it make you willing to fly on a plane like that? If there is a technical problem with the plane, you will be unwilling to fly in it especially if you had a fear of flying."
It is that perception of the Airbus A380's insecurities — no matter that the hard logic still says this plane is safe — that airlines flying the world's biggest passenger jet are likely to have to deal with.
"The problem with the A380 is that I think people have visions of the Titanic, or something," says Ian Thomas of Sydney's CAPA consulting, a firm that analyses the aviation industry.
"This is a very large aircraft that has the potential, if there is an in-flight problem, to cause immense damage. So I think it is more the 'prospect' that concerns people, rather than the reality. From that point of view, Qantas has got to overcome this perception issue."
Airbus's chief executive, Tom Enders, in Singapore this week , was asked if the wing cracking issue would lower demand for the A380. "I don't hope so," he replied. "This is unfortunate. This is us, we screwed that up. We will fix it as quickly as possible and whatever the cost is, it is too early to say at this point in time."
For now, Qantas says it sees no slackening in bookings for flights that employ the Airbus and claims it and the plane maker's openness about the cracking issue have stymied negative reactions from customers.
Maybe. But, unhappily for airlines and plane makers, convincing the flying public that cracks within aircraft wings matter little is not so easy; we are dealing with the unseen being left to the imaginations of the, largely, uninformed.
The hairline cracks have been found deep inside the aircraft's 80-metre wingspan — a structure 15.6 metres longer than the wingspan of a Boeing 747 jumbo jet. It is not just a wing. It's an enormous bladder capable of holding 320,000 litres of fuel in 10 compartments. Pumps shift the fuel from the outer wings as the aircraft comes into land to reduce stress on the bouncing wing tips. They have four metres of vertical flex.
The wings are also very intelligent limbs: mounted on them is the plane's array of wing-control surfaces, flaps and spoilers that, guided by computers, act to reduce load shocks to the wings from turbulence and flight manoeuvres.
The cracks have been discovered on some of the 2,000 brackets that connect the 60 structural ribs inside each of the plane's wings to the taut aluminium skin on the outside. Originally discovered in the Qantas A380 still under repair in Singapore, Qantas grounded another A380 on Feb. 5 after 36 cracks were discovered within the wings.
Respected US publication Aviation Week has issued an illustrated guide to the Airbus wing-crack problems.
When more serious cracks were found in the rib feet of other airline's A380s — identified as Type 2 cracks by Airbus — the European Aviation Safety Agency issued a mandatory inspection order for all A380s.
For aeronautical engineers the remedy is relatively straightforward. The suspect brackets will be replaced with strengthened versions. Separately, Airbus has suggested that, at its North Wales wing-assembly factory, adjustments may be made to the very high loads applied when metal skins are stretched and bolted to the wing's internal ribs.
Aviation literature tells us that, on almost every type of aircraft, issues with metal fatigue and cracking have arisen. Most are natural consequences of the wear and tear caused to airframes by the multiple cycles of take-offs, cabin pressurisation and landings to which any commercial aircraft is subjected.
But for passengers the problem is stark — a crack is a crack and, for most of us in our everyday lives, a crack is a precursor to a breakage.
The science that allows plane makers to expect cracks to occur, to live with them, to know their paths in advance and the speed at which they will move is difficult for most flyers, however frequent, to understand.
Plane makers know how much stress their aircraft will take, and at what point a plane's components will break. For instance, an Airbus engineer is able to tell you at exactly what moment, under what loads and where on the structure, an A380 wing will disintegrate. Airbus snapped an A380 wing at its Toulouse testing site in 2006 after progressively increasing loads upon it for a year. Just before the wing snapped, its tip flexed through a height of 7.4 metres above normal, under 1.45 times the maximum load that engineers had assessed it capable of handling.
Kim White is a Sydney aeronautical engineer who has helped design and build the A380's wing-tip fences — the large, arrow-shaped fins attached vertically to the wing tip — which were until very recently manufactured for Airbus at Hawker de Havilland's Bankstown factory.
"All aircraft generally have certain problem areas," says White. "You find when you do get fatigue cracking that it usually tends to be in the same place, that there is some particularly high-stress or design feature which isn't quite right. In the A380, because it was so big, it was a very difficult design project."
In White's assessment, the wing issues on the A380 have been caught early by the systems of aircraft inspections and airworthiness directives that make further inspections compulsory once suspicions are uncovered. "It's got the potential to be serious eventually if you did nothing but, because they are doing something, I don't think it's serious," says White.
To see the effect of serious structural fatigue on a passenger jet, it is necessary to return to the British plane maker de Havilland, which gave the us the World War II Mosquito fast bomber and, soon after, the Vampire jet. De Havilland's greatest triumph over its American rivals, Lockheed, Douglas and Boeing, came in 1952 when the de Havilland Comet flew. It was the world's first jetliner and carried its 36 passengers from London to New York in 12 hours, at altitudes, above poor weather.
A year later, Comets began to fall out of the skies. After two more crashes in 1954, a British Court of Inquiry looked for metal fatigue in sections of a downed Comet, which were recovered off the Italian island of Elba.
Using water to replicate the pressurisation of the aircraft, investigators found that stresses on the Comet's hull were far higher than ever anticipated — especially near the corners of the aircraft's square-shaped windows. It was a surprising outcome, because the Comet had already been subjected to the most rigorous pre-flight testing program of any new aircraft.
The Comet disasters contributed much to the knowledge of the dynamic stresses upon aircraft. But that intelligence didn't prevent the roof peeling off an aged Hawaiian Boeing 737 in 1988. A flight attendant was sucked out and killed before the plane landed with no other casualties. The incident sent shockwaves through the industry about the dangers of metal fatigue, causing airlines to redouble inspection efforts, investigators to cut up old planes to look for weak spots and Boeing to redesign the joints that held together its already venerable 737.
The industry maintained it had the measure of metal fatigue, but in April 2011 a 1.5-metre-wide hole opened in the roof of a Southwest Airlines Boeing 737 which was able to make an emergency landing.
America's aviation regulator, the Federal Aviation Administration (FAA) has said that the discovery of the worst metal fatigue damage in aircraft has been "a purely random occurrence" — that is, fatigue is not always found in scheduled checks.
If you're already a troubled flyer, then here is what may be disturbing about the most recent discoveries of cracks in the world's biggest passenger jet. They weren't found in any of the tightly scheduled routine checks that all passenger jets undergo. These range from 'A' checks, which occur every few hundred hours of flying, up to the exhaustive 'D' check, which sees aircraft pretty much taken apart every few years.
Instead, Qantas engineers — in Singapore helping to repair the extensive damage to the airline's A380 that suffered the engine explosion in November 2010 — found the wing cracks. That aircraft, Qantas confirms, underwent a 'C' check in September 2010 at an overseas maintenance facility — two months before its last flight.
If the cracks were noticed then, they were not reported to operators of the A380, including Qantas. A 'C' check is performed on large aircraft every year or 18 months and is the third-most extensive inspection on the scale of four.
Should the cracks have been found earlier within the routine checking system? Qantas says no, because the 'C' check does not require internal wing inspections. Yes, says Steve Purvinas, secretary of the Australian Licenced Engineers Association: "I would have expected they would have been found in a 'C' check."
"The A38Os have only been in service a short while and I am confident that these cracks would have been picked up at some stage of the maintenance schedule," Professor Brian Falzon, chair of aerospace engineering at Monash University, told The Global Mail. "It is not surprising that the cracks were picked up … during the repair of the Qantas A380, where a very thorough inspection would have been conducted to ascertain the extent of the wing damage from the engine explosion."
Qantas will be anxious that the reputation of the A380 is diminished no further.
"The A380 is incredibly important to Qantas, purely as a project," says the aviation consultant Ian Thomas. "It's seen as the future of the airline. So, from all these points of view, it's in a position now where it has got to clear up these problems as quickly as possible."
One man who carries special sway when he talks about the A380 is Richard de Crespigny, the Qantas A380 captain who saved his plane when the engine exploded. He also saved — aided of course by the Airbus's impressive array of safety systems — the plane's reputation.
He is writing a book about the A380, which will be out later this year. Happily for Qantas and Airbus, Richard de Crespigny is one who needs no convincing that the A380 is safe to fly.
"This was the biggest testament to Airbus," he told 60 Minutes in February, 2011 of his A380's performance after the explosion. "Some people might think the aircraft collapsed under the onslaught, but no aircraft is ever designed to take the beating that this aircraft got. The wing was cluster bombed. The aircraft had phenomenal damage in all systems and it didn't just recover. It performed brilliantly. It is indestructible."
Qantas is less resilient. The airline just reported an 83 per cent fall in net profit — much of it because of accelerating fuel prices and industrial action, which saw the airline ground its fleet.