Guy Norris/LOS ANGELES
Pratt & Whitney expects to begin the first test run of the PW6000 by early next month, following completion of the initial test powerplant at its base at East Hartford, Connecticut.
The 24,000lb (107kN)-thrust-rated turbofan is in development for the Airbus A318 and will begin flight tests on the new 107-seat twinjet late in 2001. The engine itself will begin flight tests on P&W's recently acquired Boeing 720 testbed by next June, according to PW6000 programme director Peter Smith.
The flight test engine and another PW6000, dedicated to blade-out tests will be assembled early next year. In all, P&W plans to have five PW6000s under test by the middle of next year, including endurance and stress measurement powerplants now entering production.
The initial phase will include fan stress tests on the 1.43m (4ft)-diameter wide chord titanium fan. These will be performed with a distorted inlet and will cover extremes of sea level starting schedules. "We will also take an initial look at temperature profiles in the turbines and stability in the compressor at sea level conditions before going to altitude tests," says Smith. High altitude operability tests will begin in the altitude chamber in mid-September.
The company is also preparing to run "a couple of combustor" configurations to match the performance of the complete engine against performance predicted by earlier rig tests. The combustor is based on the float wall configuration used in the International Aero Engines (IAE) V2500, but will employ laser drilled, film cooled panels of roughly twice the size of the IAE powerplant's. "It is aimed at being simple, low cost and low maintenance," says Smith, who adds that P&W's goal is to produce overall maintenance costs "between 25% and 30% lower than those of the CFM56-5".
The mixer will also be a key area of focus, particularly in the endurance test engine. The PW6000 has a new mixer, made from Inco 625 - a nickel alloy that the company hopes will prove to be more durable than the maintenance-intensive material used in earlier powerplants, such as the JT8D.
Source: Flight International
