Farnborough Air Show

GP7200 Adds Two New Thrust Ratings

 - July 17, 2014, 2:10 AM
Dean Athens, Engine Alliance

The Engine Alliance, a 50-50 joint venture of GE and Pratt & Whitney, has received EASA approval for two new thrust ratings for the GP7200 turbofan engine, one of the two engines available to power the Airbus A380. The new ratings bring the GP7200 to four thrust rating configurations.

One of the new ratings is for the GP7272, which allows operation to 72,000 pounds of thrust. The second is for the GP7272E, which allows the 72,000-pound thrust rating at ambient temperatures of greater than 30 deg C (86 deg F). The GP7200 family thus now has four thrust ratings, two at 70,000 pounds (the GP7270 and GP7270E) and two at 72,000 pounds (the GP7272 and GP7272E).

The “E” stands for E-rating, that which is, the “extended corner point” that lets airlines operate their A380s at the maximum thrust rating in high-ambient-temperature conditions. “The E-rating is possible because the GP7200 engine was designed with a large margin to its EGT limits,” said Dean Athans, president of the Engine Alliance.

The Engine Alliance also announced GP7200 enhancements that will improve time on wing as much as 50 percent in hot and sandy environments. The improvements primarily affect the high-pressure turbine (HPT) stage 2 nozzle module and involve a total of 25 components, including shrouds, seals and hangars; the design changes were frozen in October 2013. Hardware improvements were introduced to the production line this summer, and these can be retrofitted during quick-turn repairs or during normal shop visits, according to the Alliance. I’m excited that we’ve got better hardware and new improvements coming out. At the same time, these things bring the ability to improve our performance deterioration. As the hardware is more robust, you’re able to maintain better performance longer.”

Engineers are constantly looking for ways to continue improving the Alliance engine family, and this year the Engine Alliance released a number of controls and accessories upgrades. These include an upgraded turbine starter; an improved seal for the pressure sensors “that’s going to really drive our departure reliability higher and higher,” Athans said; an improved fuel pump; and improved materials in the control alternator.

“We’re not resting with just completing the [HPT] work. We’ve planned and are building the hardware and modules to run a full engine-endurance test, 3,500 cycles,” he said. This will be done at an MTU test cell in Munich, equipped with a special dust rig and heated inlet.

“So not only running 3,500 high-stress endurance cycles, we’re going to have dust-ingestion and a heated inlet to simulate the environment in the Middle East,” Athans said. “This test is scheduled to start the end of this year. We’ll run the full 3,500 cycles, then tear the engine down and analyze it. We’ll know if there’s more benefit to be had and we’ll validate the improvement and the goals that the engineering team set out to achieve in 2013.”

More robust hardware will maintain the engine’s performance longer, he said.