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The Rolls-Royce BR700 family of engines was developed by BMW and Rolls-Royce plc through the joint venture company BMW Rolls-Royce AeroEngines GmbH to power regional jets and corporate jets. Rolls-Royce took full control of the company in 2000, which is now known as Rolls-Royce Deutschland.
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The company was established in 1990 and the first engine run (BR710) took place in September 1994.
BR710
The BR710 is a twin shaft turbofan, entered service on the Gulfstream V in 1997 and the Bombardier Global Express in 1998. This version has also been selected to power the Gulfstream G550.
Another rerated version, with a revised exhaust system, was selected for the now cancelled Royal Air Force Nimrod MRA4s.
The BR710 comprises a 48-inch-diameter single-stage fan, driven by a two-stage LP turbine, supercharging a ten-stage HP compressor (scaled from the V2500 unit) and driven by a two-stage, air-cooled, HP turbine.
BR715
The BR715 is another twin-shaft turbofan; this engine was first run in April 1997 and entered service in mid-1999. This version powers the Boeing 717.
A new LP spool, comprising a 58-inch-diameter single-stage fan, with two-stage LP compressor driven by a three-stage LP turbine, is incorporated into the BR715. The HP spool is similar to that of the BR710.
The IP compressor booster stages supercharge the core, increasing core power and thereby net thrust. However, a larger fan is required, to keep the specific thrust low enough to satisfy jet noise considerations.
BR725
The BR725 is a variant of the BR710 with a three-stage-axial flow low pressure turbine to power the Gulfstream G650. The engine has a maximum thrust of 17,000 pounds-force (75.6 kN).
The BR725 has a bypass ratio of 4.2:1, and is 4 dB quieter than the predecessor BR710. Its 50-inch (127 cm) fan assembly consists of 24 swept titanium blades.
The BR725 prototype underwent component bench and its first full engine run in spring 2008 and European certification was achieved in June 2009. The first Gulfstream G650, with BR725 engines, was delivered in December 2011.
Variants
The BR715 thrust ratings can be adjusted by changing a plug in the FADEC controller, meaning no engine change is required. The A1-30 can become a C1-30 with a simple plug and software change.