Engine maker cranks up the hours for certification of modified powerplant for A318

Pratt & Whitney has completed the first of a three-phase flight-test programme of the final Block 4-configured PW6000 turbofan for the Airbus A318. It says certification of the 18,000-24,000lb thrust (80-106kN) engine is due for the fourth quarter of 2004, three years later than the original schedule.

Fitted with the revised six-stage MTU high-pressure compressor (HPC) in place of the original (Block 2) standard five-stage design, P&W says the Block 4 test engine has performed well since starting the programme on its Boeing 720 testbed on 3 September. Despite some nuisance issues with accessory systems, the engine "is just cranking on, and we are running up an incredible amount of hours", says PW6000 programme manager Dennis Enos.

P&W has completed simulated altitude tests on a modified PW6000 at the Arnold Engineering Development Center in Tennessee, which "demonstrated the required specific fuel consumption [7% better than Block 2] and thrust performance". The tests were demonstrated "on an initial configuration out of the box", using an engine that had originally been fitted with the initial five-stage HPC. "We had performance demonstrations scheduled for later this year and next, but now that this engine has demonstrated the final performance straight out of the box we will just complete the rest of the programme," adds Enos.

There are now three of the seven planned engines running in the tests. These include the test engine on the flying testbed, one on general development, higher-temperature endurance tests at West Palm Beach, Florida, and another which began build-up runs for a simulated block test at East Hartford, Connecticut in early October.

On top of more than 350 flight test hours amassed during evaluation of the original five-stage engine on the A318 development aircraft, which concluded in July, the Block 4 engine is scheduled to build an estimated 90h on the 720 flying testbed. This will conduct a second flight-test phase before year-end, and a third phase early in the second quarter of 2004.

P&W is using an aggressive pricing policy in an effort to recover ground lost to CFM International's CFM56-5 on the A318. The first three A318 flight-test engines will be delivered in late 2004, with entry-into-service planned for a year later.

Airbus chief executive Noel Forgeard says A318 deals from Mexicana and Romanian airline Tarom "should close in the coming months". Tarom has a memorandum of understanding for four A318s, while Airbus says Mexicana is "still discussing precise numbers...we're talking tens rather than single digit units".

Source: Flight International