Rolls-Royce says it has increased the power of the engine it supplies for US V-22 Osprey tilt-rotor aircraft by 17 percent. (photo USMC)
Sep. 16, 2013 - By AARON MEHTA – Defense News
WASHINGTON — Engine manufacturer Rolls-Royce has increased the power output of its V-22 Osprey engine by 17 percent, a significant jump that should boost the reliability of the tilt-rotor aircraft in high-altitude, high-heat conditions, according to a company official.
“We’ve been upgrading the [AE family] of engines to provide more thrust as more challenging requirements came up in the commercial market, so we knew there was more power available” said Tom Hartmann, the company’s senior vice president of defense. “Now that we’re through the hurdles of wrestling and working the time-on-wing improvements, we recognize there is additional capability we haven’t taken advantage of that could provide high power to the Pentagon for their particular missions.”
The engine improvements came from three relatively small changes. First, the company added a new turbine to the engine, known as the Block 3 turbine. That design is based on a commercial product Rolls-Royce has used.
Some of those turbines are already in the field; the company has been installing them into all new-production models since July 2012, and began upgrading older turbines during regular maintenance two months later.
The other modifications included an increase in the flow capacity of the fuel valve and a software update, which allow the engines to deliver the higher power when needed.
Each V-22 Osprey is powered by a pair of Rolls-Royce AE 1107C engines. The US Air Force’s fleet of CV-22s are used for special operations missions. The US Marine Corps’ MV-22 has two variants, the B and C models, which are used in the transportation of troops and equipment.
Most of the time, the V-22 won’t need the extra power. It’s really designed for use at higher altitudes — the 6,000-8,000-foot range — where the V-22 has struggled.
“Without flight tests, it’s hard to say the real-world impact” of the improvements, Hartmann said. But Rolls aims to give US military operators full engine capability at 6,000 feet with an air temperature of 95 degrees, a challenge that he said Air Force officials asked the company to look at.
“Right now, they are limited on what load they can carry at 6,000 feet and 95 degrees.” Hartmann said. “The plan is to provide that full capability in the near term, and then, in a future upgrade, give enhanced capability at 8,000 feet and 95 degrees.”
The company will begin tests of its upgraded engine in the fall, beginning the Federal Aviation Administration review process. Hartmann expects kits for the improved engines to arrive late 2014.
Rolls also is keeping an eye on a more comprehensive Block 4 upgrade, which should increase power by 26 percent over the current baseline, allowing the engines to hit close to 10,000 horsepower. It also could improve fuel consumption, which the company expects to be key as the Pentagon focuses more on the Asia-Pacific region.
“You have the ‘tyranny of distance’ in the Pacific, so better fuel consumption is obviously a benefit in that region,” Hartmann said.