The Rolls-Royce Trent XWB engines installed on the first flight-test Airbus A350 XWB have run for the first time.
Airbus powered up the Rolls-Royce Trent XWB engines on the first flight-test A350 XWB (which it calls MSN1) on June 2 after starting up the aircraft’s auxiliary power unit (APU), as part of the preparations for the aircraft’s maiden flight.
The Airbus A350 XWB is a new, mid-size, long-range widebody aircraft family with three versions (the A350-800, A350-900 and A350-1000) seating from 270 to 350 passengers in typical three-class layouts.
According to Airbus, the A350 XWB family will bring a step change in efficiency compared with existing aircraft in this size category, using 25 per cent less fuel and providing an equivalent reduction in CO2 emissions.
Much of the fuel-burn improvement over today’s similarly sized aircraft comes from the engines. Rolls-Royce says the Trent XWB is the most fuel-efficient large-turbofan engine yet developed.
Rolls-Royce Trent XWB engines have already been extensively flight-tested on Airbus’ A380 in-house flight-test aircraft.
Scheduled for entry into service in the second half of 2014, the A350 XWB family has already won firm orders for 616 aircraft from 34 customers worldwide.
The Rolls-Royce Trent XWB is the only engine type offered to date on the A350 XWB family. Rolls-Royce says the Trent XWB is the fastest-selling large turbofan ever, having sold 1,250 or more engines to 34 customers before the A350 XWB has even made its first flight.
With a planned maximum thrust range of 75,000lb to 97,000lb (333.6 kilonewtons to 431.5kN), the Trent XWB is the highest-thrust Trent engine version Rolls-Royce has developed to date.
Like all other Trent (and earlier RB.211-family) engines, Rolls-Royce employs a unique three-spool engine architecture to derive as much propulsive and thermal efficiency as possible from its large turbofans.
(Both General Electric and Pratt & Whitney (P&W) use a two-spool architecture in their large turbofans, though P&W has developed the geared-turbofan concept for its new PurePower PW1000G family of medium-size turbofans and says the concept ultimately may be developed for a large-fan engine.
P&W’s geared-fan PW1000G is often referred to within the aerospace industry as “a two-and-a-half-spool engine”, because it employs an extra shaft between the main reduction gearbox ‒ which is powered by the low-pressure spool ‒ and the fan itself.)
The Trent XWB’s engine architecture features the fan (which is effectively the engine’s low-pressure compressor); eight intermediate-pressure compressor stages; six high-pressure compressor stages; an annular combustor containing 20 fuel-spray nozzles; one high-pressure turbine stage; two intermeidate-pressure turbine stages; and six low-pressure turbine stages.
It is controlled by a dual-channel, full-authority digital engine control (FADEC) unit.
The Trent XWB is 228.8 inches (581.2 centimeters) long from the tip of its fan spinner to the rear of its cold-air nozzle; 78.8 inches (200.1 centimeters) wide not including the width of the fan section and fan casing at the front of the engine; and has a maximum dry weight of 16,043lb (7,277 kilograms) not including fluids, nacelle or aircraft-interface parts.
Initial versions of the Rolls-Royce Trent XWB family have a 118-inch (299.7-centimeter) fan and develop maximum take-off thrust of 84,000lb (373.65kN) for the Airbus A350-900 (the first version of the A350 XWB to fly) and 75,000lb (333.6kn) for the shorter A350-800 version which is the next version of the A350 XWB family that Airbus plans to develop.
Another version of the Trent XWB for the Airbus A350-800 and A350-900 offers 79,000lb (351.4kn) of take-off thrust.
The European Aviation Safety Agency (EASA) has already certificated the A350-800 and the A350-900 versions of the Trent XWB, awarding them their type certificate on February 7 this year.
Rolls-Royce is now developing the 97,000lb-thrust version of the Trent XWB for the Airbus A350-1000. The company has already achieved thrust levels of over 100,000lb (444.8kN) in ground-test runs of the A350-1000 engine, but the engine has yet to be flight-tested and certificated.
In a parallel development, the UK-based engine manufacturer is also now developing the Trent 1000 TEN engine which it plans to offer on the Boeing 787-10X.
Singapore Airlines having ordered 30 Boeing 787-10X aircraft last week, the 787-10X program is as good as launched, though Boeing has yet to confirm formally that it is launching the program. A launch decision is confidently expected within the next few months ‒ perhaps at the Paris Air Show, which begins on June 17.