Rolls-Royce was warned months ago about the safety of the engine model powering a Qantas aircraft forced to make an emergency landing yesterday.
The airline’s chief executive, Alan Joyce, said this morning that a ‘design issue’ may have caused the engine failure on the Airbus A380 aircraft forced to return to Singapore shortly after take-off.
This followed the emergence of warnings made in August by the European Aviation Safety Agency (EASA) of ‘wear, beyond Engine Manual limits’ and conditions that ‘present a potential unsafe condition to the aeroplane’ in relation to the Trent 900 engine.
In an airworthiness directive, EASA said wear was found on the splines of the intermediate pressure (IP) turbine that required inspection. Rearward movement of the turbine ‘would enable contact with static turbine components and would result in loss of engine performance with potential for in-flight shut down, oil migration and oil fire’, it said.
Joyce said the problem with the Qantas aircraft was an engine issue and not related to the airworthiness of the plane. ‘We believe this is probably most likely a material failure or some sort of design issue,’ he told reporters in Sydney.
Rolls-Royce issued a statement yesterday saying the process of precautionary engine checks was underway. A spokesperson told The Engineer it was important to note that the investigation was still at an early stage.
Eyewitnesses reported seeing one of the plane’s engines explode before the plane carrying 440 passengers and 26 crew returned to Singapore. The aircraft landed safely and, according to Qantas, there were no injuries to any passengers or crew.
Airbus said in a statement that it had asked all A380 operators with Rolls-Royce engines to inspect the planes. Qantas has grounded its fleet of A380s but Singapore Airlines has resumed flights after delays yesterday.
Commentators have suggested multiple explanations for the engine failure, emphasising that a full investigation would be needed for a concrete verdict.
Dr Ranjan Vepa, lecturer in avionics at Queen Mary, University of London, said: ‘The uncontained engine failure could also have been caused by a combination of circumstances that could have triggered a sequence of enabling events leading to the uncontained engine failure almost immediately after take-off.
‘This naturally tends to make one suspect that the engine was probably hit by something that caused the engine inlet to be blocked, which in turn could have triggered a sequence of events leading to the turbine trying to operate faster or even a “fire” within the combustion chamber.’
John Turton of the Institution of Engineering and Technology Aerospace Network, said: ‘From the initial reports it appears that this incident was caused by some kind of uncontained failure in the hot end of the engine.
‘The underside cowling parts that were blown off are around the turbine area and there has been one piece of video looking out from the cabin that shows a radial puncture through the upper surface of the wing, apparently adjacent to the turbine section.
‘This would indicate that there was considerable force involved in ejecting material from the engine in this location.’