Rolls-Royce Trent 800 engines, the first to be certificated at 400kN, will power the Boeing 777-300s recently ordered by Cathay Pacific Airways and Thai Airways International. R-R has defined a thrust level of 423kN for the initial -300 A-market stretch, saying that this can be achieved with adjustments to the high-pressure and intermediate-pressure turbines, with other changes to increase core flow. The company adds that further growth will be possible without increasing the Trent 800's 2.8m diameter fan.
The first Trent 800-powered 777-200, meanwhile, had its maiden flight on 26 May, and flight-testing has progressed smoothly, despite a one-month delay following the discovery of fatigue cracks in the aircraft's Boeing-designed engine strut fairings.
Initial Trent 800s will be de-rated to thrust levels of between 335kN and 375kN, and the engine is due to enter commercial service on a Thai 777-200 in January 1996.
Five Trent 700-powered Airbus A330s are now in service with Cathay Pacific and Dragonair, following certification in December 1994, and R-R's large turbofans continue to build on their reputation for reliability. In May, an RB211-535E4 turbofan engine powering a Boeing 757 was removed for overhaul after completing a record 24,100h and 8,742 cycles continuously on-wing.
The RB211-524H, however, is now subject to additional inspection procedures following an incident in which a core fairing aft of the combustion chamber burned through on a British Airways Boeing 747-400. Modifications have now been introduced to rectify the problem.
R-R completed its acquisition of Allison Engines in March, giving the UK group a route back into the turboprop market after deciding against developing a follow-up to the successful Dart. On the military side, R-R will be prevented from gaining access to Allison's work, on classified defence programmes, such as the US Integrated High Performance Turbine Engine Technology project.
R-R is continuing its role, in the development of the McDonnell Douglas (MDC) AV-8B Harrier, with R-R-designed "zero-scarf" aft exhaust nozzles being flight-tested on an MDC technology demonstrator aircraft. The new nozzles, fitted to the Harrier's R-R Pegasus vectored-thrust turbofan, are designed to improve engine reliability and increase thrust.
Source: Flight International
