PAUL LEWIS / WASHINGTON DC
Airbus needs to be convinced solution is achievable
Pratt & Whitney has taken an internal decision to retrofit its PW6000 turbofan with MTU's HDV12 high-pressure compressor (HPC) if it can reach agreement with Airbus on restructuring the troubled A318 engine programme, according to industry sources on both sides of the Atlantic.
The US manufacturer had been considering developing a new seven-stage HPC itself to replace the existing five-stage design, which has underperformed and resulted in the PW6000 falling 6% short of its specific fuel consumption target. The engine is currently being flight-tested on the A318.
Munich-based MTU has been working on the six-stage HDV12 for several years and designed the unit as a drop-in alternative for the PW6000. The decision to make the switch represents a U-turn for P&W, which had rejected the HDV12 in 2000 in favour of its own five-stage HPC.
Recent bench tests of a PW6000 equipped with the HDV12 in P&W's altitude chamber helped convince the manufacturer that switching to the MTU design was the best option, say the sources.
P&W is now attempting to convince Airbus that it has an achievable solution and realistic schedule for meeting performance guarantees on the A318 after being forced to delay the entry into service of the PW6000 by more than two-and-a-half years. P&W is not commenting on its decision until these talks have been concluded.
The selection of the HDV12 will double MTU's industrial share of the PW6000 to more than 30%. The Munich-based company is already responsible for the engine's low-pressure turbine as a "preferred supplier". MTU may take a risk-sharing stake in the restructured programme, say the sources.
With its extra stage the HDV12 has a higher parts count than the existing five-stage unit, but weighs about the same due to the use of advanced materials.
The PW6000's entry into service on the A318 has slipped from late this year to mid-2005. The design change comes too late for a number of A318 customers which have switched to the rival CFM International CFM56-5B, which is now the lead powerplant on the aircraft. British Airways is scheduled to be the first carrier to receive the PW6000-powered A318, although it recently halved its order for the type from 12 to six aircraft.
Additional reporting by ANDREW DOYLE in SINGAPORE
Source: Flight International
