Pratt&Whitney tests A320NEO geared turbofan

Pratt&Whitney has successfully performed the first test run of the new PW1100G geared turbofan engine, designed for the A320NEO. A spokesperson said the first time they applied power to the igniter the engine immediately fired up. The first test was performed November 28th, at the West Palm Beach FL test site.

They say it's too early to tell if the fuel burn calculations are accurate, but the test showed the pre-test predictions for temperature, and speed were right on. The engine completed the break in cycle with no problems.

The second test engine will be joining the test program sometime in February, with a certification target of 2014. The second engine will be used for operability and performance trials, cross wind testing, as well as fan mapping tests. This engine will be flown on the 747SP flying test bed, with a production-representative variable nozzle mounted.

The third and fourth engines will be heavily instrumented for stress testing to get strain-gauge data on the high and low pressure spools. Those two engines will enter the build cycle earlier than normal engines, because of the amount of wiring installed.

A total of eight engines will enter the test program, aiming for an August 2014 certification ahead of the first flight of the NEO airframe. Block 2 engines will undergo a simultaneous FAA/EASA certification process which will include bird ingestion, fan blade out, and endurance.

Another version of the engine is under development for the Irkut MS-21. The difference between the engines is the placement of some components, such as the accessory gearbox. Pratt and Irkut are working with Shorts on the nacelle for that engine. The PW1400G is the only Western powerplant available for the MS-21 under and agreement signed by the two companies.

Meanwhile the PW1200G that is under development for the Mistubishi MRJ has completed 1600 hours of testing, and is in line with the development of the aircraft. The first flight of the MRJ has been delayed until 2015.

A full moon hung over Pratt & Whitney's test site the night its Airbus A320NEO engine ran for the first time. Whether this was a good omen or not, the company knows only a successful test effort will prove if its pivotal gamble on geared turbofan technology was correct.

Pratt began its march back into the single-aisle mainstream at 11 p.m. on Nov. 28, when the first PW1100G NEO engine fired into life on the company's West Palm Beach, Fla., test stand. “The first time we put power to the igniter it lit,” says the engine maker's Next-Generation product family Vice President Bob Saia. Since then, the engine has been taken through a 'break-in' cycle from idle to full thrust, ensuring the mechanical integrity at various power levels before clearing the PW1100G for the remainder of the forthcoming test effort.

Although it is too soon to know whether the engine is on track to meet critical fuel-burn targets, the overall performance from a temperature and speed perspective “is right on pre-test predictions,” says Saia. “We haven't yet got a true calibration in terms of fuel efficiency,” he adds. Mechanically, the engine has completed the break-in cycle testing with “no anomalies. We're really pleased with what we got.”

The initial work allows Pratt to make some design tweaks to optimize the engine at the early stages if needed. It also incorporates lessons learned from the two forerunner geared turbofan (GTF) developments, the PW1500G for Bombardier's CSeries airliner and the PW1200G for the Mitsubishi Regional Jet (MRJ). “On the PW1500G, for example, we had an unexpected rub in the last stage of the low-pressure compressor. This wasn't due to the way we broke in the engine, but because of the way it was designed,” says Saia, who adds that a quick change corrected this “subtlety.” Similarly, the initial runs also indicated that designers had allowed too much clearance in the PW1500G high-pressure compressor, which had to be tightened.

Source