Rolls-Royce has introduced the first of a two-phase performance improvement for the Trent 900 engines that power the Airbus A380 airliner. Turbofans now being delivered to A380 operators have a one-percent improvement in specific fuel consumption compared with the initial units. Second-phase improvements that are due to enter service during 2013 will deliver a further 0.8-percent reduction in fuel burn.

Trent 900 program director Rosie Toogood explained that all the improvements introduced focus on improving air flow and cooling the engines. The first performance improvement package includes new elliptical leading edges (ELEs), greater low-pressure tip clearance and a new hard coat for the high-pressure compressor drum. The second performance improvement package now being finalized will cover the following elements: optimized fan-blade tip clearance, improved cooling of the turbine case, improved sealing for the low-pressure turbine, ELEs for the engine section stators, reprofiling of engine frames and improvements to the air system.

Toogood said the Trent 900 improvements have been engineered directly as a result of progress made with Rolls-Royce’s new Trent 1000 and Trent XWB engines (to power the Boeing 787 and A350XWB, respectively). On October 18, Airbus installed the first Trent XWB test engine on an A380 testbed being used for the A350XWB development. Other new features have been derived from the Trent 700EP turbofan, and also from the V2500Select and the latest versions of the AE3007. More than half the improved features will be retrofitable during overhauls.

According to Peter Johnstone, Rolls-Royce’s head of marketing for Airbus programs, the Trent 900 is now the most environmentally friendly powerplant available to A380 operators. He claimed that it now promises the lowest lifetime fuel burn, the smallest carbon footprint (in terms of carbon dioxide), and the lowest emissions levels for nitrous oxide, carbon monoxide and unburnt hydrocarbons (but not yet for smoke emissions).

To date, 11 of the 16 A380 operators have selected the Trent 900, and so far 30 Trent-powered are in service. Those operators include Malaysia Airlines, which is to start taking delivery of the six A380s it has on order in the second quarter of 2012; the first of those six made its first flight on October 20. The Trent 900 has almost logged one million flight hours and more than 103,000 flight cycles.

Last week, Rolls made the 1,000th delivery of the Trent 700 engine that power the Airbus A330. It has been supplied for an aircraft to be operated by Cathay Pacific, which was the first Trent 700 operator back in 1995.

The Trent 700 also has been upgraded with an enhanced performance package, which delivers a one percent reduction in fuel burn. It is based on changes similar to those now offered for the Trent 900.