Rolls-Royce's Pearl 700 engine programme has achieved further testing milestones on its way to certification and entry into service in 2022, reaching more than 8,000 test cycles and more than 3,000 testing hours.
During the test campaigns the Pearl 700 proved its reliability and performance under extreme conditions, experiencing cold start temperatures, where fuel viscosity is comparable to honey. It is reported to have performed equally well in hot conditions, completing long, high power endurance runs and high cycle tests, and has successfully demonstrated that it can run on 100% SAF.
The flight test programme began in February 2020 and is progressing with a fleet of five flight test aircraft and one production test aircraft. The Pearl 700 engines have already powered Gulfstream's G700 beyond its maximum operating speed and cruise altitude, flying nearly as fast as the speed of sound at Mach 0.99 while reaching an altitude of 54,000ft, it says. In typical operations, the aircraft has a maximum operating speed of Mach 0.925 and a maximum cruise altitude of 51,000 ft, which allows it to fly above commercial air traffic and the weather in the troposphere. During its first international visits to the Middle East and Europe the aircraft set two city pair speed records and a third speed record on its return trip to the United States.
Dr Dirk Geisinger, director business aviation, Rolls-Royce, says: “Seeing the Pearl 700 programme running at such a fast pace makes me really proud of the team behind it. In addition to the extensive ground testing, the flight test campaign is progressing exceptionally well. Today, it stands at more than 3,000 engine flying hours from more than 2,000 engine flights and with the G700 test aircraft fleet in the air these numbers are increasing daily.”
It combines the Advance2 engine core, with a new low-pressure system, resulting in an 8% increase in take off thrust at 18,250lb compared to the BR725 engine. It says the engine offers a 5% higher efficiency, while maintaining its class-leading low noise and emissions performance.
The engine includes a highly efficient blisked fan, a high pressure compressor with a pressure ratio of 24:1 and six blisked stages, an ultra-low emissions combustor, a two stage shroudless high pressure turbine and an enhanced four stage low pressure turbine that is one of the most efficient and compact in the industry.