Pratt & Whitney aims to begin testing a more advanced geared-turbofan demonstrator engine within four years, incorporating new technologies to head off any threat from rival manufacturers in the battle to power the single-aisle replacements from Airbus and Boeing.
This proposed 'advanced GTF' engine will deliver up to 10% more efficiency that the current version, giving it at least a 20% advantage over today's powerplants.
Speaking at an event in Toulouse to officially mark the end of the current GTF demonstrator's flight-test campaign on Airbus' A340-600 test-bed, P&W vice-president for the next-generation product family Bob Saia said the engine maker had identified its "next step of technology features" and expects to begin testing advanced concepts on a demonstrator by 2013.
"The GTF that enters service in 2013 is in the 12-15% [lower fuel-burn range than current engines] and we'd like to improve fuel consumption by another 8-10%, so we'd be looking at a total of around 20%," he says.
The areas being examined "touch all aspects of the engine", he says, including aerodynamics, lightweight materials, improvement of core thermal efficiency, and use of more temperature-capable material.
"We want to make the fan bigger and increase the gear ratio from 3:1 on the current GTF to 4:1 or 5:1 to increase propulsive efficiency," he adds.
Saia says that P&W launched the programme in mid-2008 and aims to start laboratory and wind-tunnel testing some of the features in 2010, ahead of flying a full-scale demonstrator in late 2012-13. He says this timetable will enable P&W to have the advanced GTF available in the 2017-2019 timeframe, depending upon when specific aircraft will require new powerplants.
Although the advanced GTF is aimed at the expected single-aisle replacement aircraft from Airbus and Boeing, Saia says that P&W has had no discussions with either company about operating a joint flight-test programme with the demonstrator.
While the current GTF demonstrator uses the core of the existing PW6000 engine, Saia says the advanced GTF demonstrator will adopt the core from one of the production PW1000G GTF engines being developed for the Bombardier CSeries and Mitsubishi MRJ regional jet - possibly with advanced technology incorporated. He adds the aim is to enable as much of the technology to be developed for the advanced GTF transferrable to the first-generation PW1000G GTFs.
"Through all the work that we do on the fundamentals of the engine to improve efficiency we will introduce new designs that will go as a minimum on new-production engines, so it's conceivable that a good proportion of the advanced GTF improvements will be available [to the CSeries or MRJ]," says Saia. "Whether they're retrofittable to the existing engines will be a function of how or when we introduce those designs."