quinta-feira, 25 de novembro de 2010
A380 Salvo pela competência da tripulação
Damage to Qantas plane. Source: HWT Image Library
A QANTAS A380 was a flying wreck after an engine exploded last week, shooting metal through fuel tanks.
Last week's mid-air emergency off Singapore also badly damaged a wing, which may have to be replaced.
The Herald Sun can reveal the full list of damage as the big jet was nursed back to Singapore on three engines.
When it touched down the fuel systems were failing, the forward spar supporting the left wing had been holed and one of the jet's two hydraulic systems was knocked out and totally drained of fluid.
Sources compared the A380 to the Memphis Belle, the World War II bomber that struggled back to England from Germany on its final mission and became the subject of an award-winning 1990s Hollywood movie by the same name.
Richard Woodward, vice-president of the International Air Pilots' Federation, told the Herald Sun yesterday that the lesson from the near disaster was the value of an experienced flight crew.
"There was a wealth of experience in the cockpit, even the lowest ranked officer on board had thousands of hours of experience in his former role as a military flying instructor," said Capt Woodward, himself an A380 pilot on leave from Qantas.
As another senior pilot said: "It is bad enough for an engine to explode in mid-air let alone lose so many secondary systems".
Investigators found shrapnel damage to the flaps, a huge hole in the upper surface of the left wing and a generator that was not working.
The crew could not shutdown the No. 1 engine using the fire switch.
As a result the engine's fire extinguishers could not be deployed.
Captain Richard de Crespigny, first officer Matt Hicks and Mark Johnson, the second officer, could not jettison the volume of fuel required for a safe emergency landing.
With more than 80 tonnes of highly volatile jet kerosene still in the 11 tanks -- two of which were leaking -- they made an overweight and high speed approach to Changi Airport.
Without full hydraulics the spoilers -- the hinged flaps on the front of the wings -- could not be fully deployed to slow the jet.
The crew also had to rely on gravity for the undercarriage to drop and lock into place.
On landing they had no anti-skid brakes and could rely on only one engine for reverse thrust -- needing all of the 4km runway at Changi to bring the jet to a stop.
The three crew have been interviewed by Australian investigators and cleared to return to duties.
Industry sources said the damage will almost certainly put the airline's flagship jet -- the Nancy Bird-Walton -- out of service for months.
Investigators found that an oil fire may have caused the engine to explode.
Details of the stricken jet's problems were revealed yesterday in an emergency directive by the European Aviation Safety Authority.
The authority made it mandatory for airlines with the now suspect Rolls-Royce Trent 900 engines to make checks for excess oil.
If not detected, excess oil can cause a fire and ultimately result in "uncontained" engine failure, with potential damage to the aeroplane and to people or property on the ground.
Qantas made it clear it will keep its six superjumbos grounded indefinitely and has rearranged flight schedules using substitute aircraft.
"The specific checks mandated by the directive were already being carried out by Qantas in conjunction with Rolls-Royce," it said.
"Qantas's A380 aircraft will not return to service until there is complete certainty that the fleet can operate safely."
WHAT WENT WRONG ON QF32
Damage to the A380
1 Massive fuel leak in the left mid fuel tank (there are 11 tanks, including in the horizontal stabiliser on the tail)
2 Massive fuel leak in the left inner fuel tank
3 A hole on the flap fairing big enough to climb through
4 The aft gallery in the fuel system failed, preventing many fuel transfer functions
5 Problem jettisoning fuel
6 Massive hole in the upper wing surface
7 Partial failure of leading edge slats
8 Partial failure of speed brakes/ground spoilers
9 Shrapnel damage to the flaps
10 Total loss of all hydraulic fluid in one of the jet's two systems
11 Manual extension of landing gear
12 Loss of one generator and associated systems
13 Loss of brake anti-skid system
14 No.1 engine could not be shut down in the usual way after landing because of major damage to systems
15 No.1 engine could not be shut down using the fire switch, which meant fire extinguishers would not work on that engine
16 ECAM (electronic centralised aircraft monitor) warnings about the major fuel imbalance (because of fuel leaks on left side) could not be fixed with cross-feeding
17 Fuel was trapped in the trim tank (in the tail)creating a balance problem for landing
18 Left wing forward spar penetrated by debris
Pelas fotos, lista de danos , e informações somente agora disponibilizadas podemos concluir graças a uma tripulação extremamente competente a explosão do motor dois do Airbus não acabou em tragédia
Este quase acidente coloca um ponto de interrogação sobre a segurança do maior avião de passageriros do mundo e dos motores RollsRoyce.
Os motores da série Trent que começaram com -500 estão presentes em milhares de aeronaves são modernos eficientes e econômicos, porem desde as primeiras séries tem apresentado problemas incipientes com o sistema de óleo. Na série 900 que é usado pelo A380 e na 1000 que será usado pelo Boeing 787 este problema aumentou. Antes da explosão do motor do avião da Qantas ocorreu uma problema semelhante com um motor de série 1000 durante um teste na Boeing. Estes dois modelos de motores são praticamente iguais, portanto a fabricante Inglesa terá muito trabalho para recuperar a sua imagem que ficou arranhada.
O Airbus A380 mostrou muitas fragilidades para um avião deste porte, vejam extensa lista de danos no final do artigo escrito na língua inglesa, o que é inaceitável que muitos sistemas essenciais ao voo sejam afetados por uma falha grave de um motor.
O que ocorreu lembra muito um acidente que aconteceu com um DC10 ande a explosão do motor dois ocasionou a perda dos tres sistemas hidráulicos, obrigando o fabricante à fazer modificação para o problema não repetir.
Certamente este acontecimento tornara necessário a implantação de muitas alterações no A380, alguns sistemas terão que ser ré-arranjados, outros protegidos. Portanto a fabricante Européia terá muito trabalho para recuperar a confiança no seu maior avião.