Posts Tagged ‘Trent 900’

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Something amiss with the Qantas version of the Rolls Royce Trent 900 engines

November 8, 2010

Singapore Airlines has just announced, according to Reuters, that it had completed engine inspections on all its Airbus A380 aircraft and did not find any issues of concern.

“We have completed the engine inspections on all our A380 aircraft and did not find anything of concern,” SIA spokesman Nicholas Ionides said on Monday.

“The findings of the inspections have been reviewed with Rolls-Royce. Any further checks that may be recommended by the manufacturers will of course be done, and in the meantime we continue with our regular routine checks.”

Meanwhile,

Australia’s Qantas said on Monday it would keep its A380 fleet grounded for at least another 72 hours after discovering problems on three more of the superjumbo’s engines.

Singapore has 11 A 380s powered by Rolls Royce Trent engines while Qantas has 6 Airbus A 380s. The Wall Street Journal reports:

Qantas Airways Ltd. on Monday said its engineers found oil leaks in Rolls-Royce Group Ltd. engines on three of its grounded fleet of A380 jetliners, amid an investigation into the blowout of a turbine that forced one of its double-deck superjumbos to make an emergency landing in Singapore last week. “These engines are not performing to the parameters you would expect,” said Alan Joyce, chief executive of Qantas, in a press conference in Sydney. “The oil leaks were beyond normal tolerances.”

Mr. Joyce added that the Rolls-Royce Trent 900 engines that Qantas operates on its fleet of A380s are designed to provide more thrust and torque, and that this version of the turbine could be at fault. Engineers have identified oil leaks on engines from three separate Qantas A380s, one currently grounded in Sydney and two other aircraft in Los Angeles, he said.

Mr. Joyce said that Qantas uses a different design of Trent engine than those used by Singapore Airlines and Deutsche Lufthansa AG on its A380s.

The problem seems to be narrowing down to either the particular version of the Rolls Royce Trent 900 engine used by Qantas or the particular maintenance regime or procedures applying to the Qantas engines. In either case it should be of some cheer to Rolls Royce that the problem may not – on the surface – be a generic design fault with the Trent engines but something restricted to the engines as used by Qantas.

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Posted in Aviation, Engineering, Technology | 3 Comments »

Trent 900 vs. GP7200: Competitive pressures getting too hot?

November 5, 2010

There are only two engines suitable for the A 380 – Rolls Royce’s  Trent 900 and its rival the GP7200 manufactured by the General Electric/Pratt & Whitney Engine Alliance.

Nov. 2012- Image updated: from http://www.enginealliance.com/engine_features.html

Engine Alliance GP7200: image http://www.enginealliance.com/

It is highly unlikely that the aircraft industry would ever allow a situation to arise where there was only one supplier of engines. A monopoly is something to be avoided at all costs in any purchaser / supplier arrangement. It follows that for the airlines and the airplane manufacturers that the market (in this case the number of A 380s) be split between the two suppliers such that:

  1. neither supplier gains a dominant market position such that it can dictate the engine price,
  2. each supplier has a large enough market share and sufficient earnings such that their continuation in the market is not jeopardised (for the sake of spares, service, development of new engines and, above all, to avoid a monopoly situation arising by the exit of one supplier).

Trent 900 cut away: epower-propulsion.com

If either engine supplier has an uncompetitive product – whether for price or for performance – the monopoly becomes inevitable and immediately jeopardises the continuation of the market itself. So if only one engine supplier was available, the A 380 itself becomes non-viable.

In this restricted market place, it would seem, a win-win situation should not be impossible. Yet the competition between the protagonists is intense and the technology boundaries are under constant pressure as each supplier tries to gain a competitive edge over the other. Each engine manufacturer knows that he will not be permitted to gain a market-dominant position. But the costs of engine development are so high that every little gain in market share is hotly pursued.

For the airline industry, fuel cost is a dominating cost element and even minute gains in fuel efficiency are well worth pursuing. The intense competition between the two engines for the A 380, is centred around fuel efficiency. The GP7200 is generally thought to have a 1% advantage. It also seems to be the strategy for the U.S. engine makers to constantly maintain this performance gap over their competitor as each tries to improve performance. The Trent 900 has a slightly higher thrust(about 3%) and prices are, of course, a closely guarded secret.

For fuel efficiency therefore it seems that Rolls Royce is playing catch-up. To get a decisive advantage each new improvement must be sufficient to go past the competitor – who in turn will introduce improvements to regain his advantage. But fuel efficiency is not easily gained.

  • Higher temperatures can give improved efficiency but lead to the need for new materials to handle the higher stresses at the higher temperatures,
  • reduced clearances can reduce leakage losses and increase efficiency but require increased manufacturing accuracy and can increase the possibilities of wear
  • more complex designs are devised where component positions can be changed during operation to optimise efficiency at different operating conditions but which increase the possibility of unwanted contacts within the engine.

That this competitive pressure leads to innovation is – I think – beyond doubt. But the Trent 1000 has had an “uncontained” explosion on the test bed. The Trent 900 has had one in flight.

The question that comes to mind is whether the competitive pressure and the quest for fuel efficiency has led to “too much – too quickly” for the Trent ?

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Posted in Aviation, Business, Engineering, Technology | 9 Comments »

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