Rolls-Royce has announced at the show that it has achieved three key milestones in the development of the lift system that enables the F-35B Joint Strike Fighter (JSF) to achieve its short take-off and vertical landing (STOVL) capability.
The engine has successfully completed a test demonstrating the propulsion system specification life requirement of 1,500 engagements of the lift-fan clutch. The clutch enables transition from conventional to vertical flight by transmitting power from the main engine during an engagement. Demonstration of the required clutch life represents a greater than 10-fold increase in life since the successful JSF concept demonstration flights in 2001.
Earlier this month, a Rolls-Royce lift fan began the first in a sequence of STOVL tests to measure operational capability. The lift fan, a 50in (1.3m), two-stage, counter-rotating fan driven from a conventional gas turbine, supplies the forward vertical lift for the JSF aircraft.
Testing is taking place at the new $20 million Rolls-Royce facility, which opened last month in Indianapolis, Indiana.
The hat-trick of achievements was completed last week with the assembly, successful functional test and shipment to Pratt & Whitney of the first three-bearing swivel module (3BSM); the swivelling jet pipe that is capable of redirecting the rear main engine thrust from the horizontal to the vertical in just 2.5s.
Speaking at the show, Chris Cholerton, programme director for Rolls-Royce, said: "These three milestones mark a tremendous technical and schedule achievement that provides confidence in the design and durability of these unique components and significant risk reduction for the STOVL propulsion system.
"These achievements illustrate that lift system activity is on-track and gathering pace towards the next major milestone - the first F135 STOVL propulsion system test in three months' time."
All three milestones form part of the F135 system development and demonstration (SDD) programme. Rolls-Royce is teamed with Pratt & Whitney to develop the JSF F135 STOVL propulsion system and ensure interchangeability with the GE Rolls-Royce F136 engine. Rolls-Royce is responsible for the lift system components, including the lift fan, the 3BSM and the roll posts.
Potential orders for the JSF are estimated at over 3,000 aircraft worldwide, of which approximately 750 are expected to be the STOVL variant.
GEOFF THOMAS
Source: Flight Daily News
