F136 Engine
The F-35 is a next-generation, multi-role stealth aircraft designed to replace the AV-8B Harrier, A-10, F-16, F/A-18 Hornet and the United Kingdom’s Harrier GR.7 and Sea Harrier, all of which are currently powered by GE or Rolls-Royce motor making them the engine powers of choice for the U.S. and U.K. militaries. Potential F-35 production for the U.S. Air Force, Navy, Marines and international customers, including the UK Royal Air Force and Royal Navy, may reach as many as 5000 to 6000 aircraft over the next 30 years.
The Pratt & Whitney F135 will be fully and physically interchangeable with the GE Rolls-Royce F136 engine to power the F-35 Joint Strike Fighter (JSF). The Pratt & Whitney F135 will be the exclusive power for the JSF's first flights beginning in the third quarter of 2006. The GE Rolls-Royce F136 engine was expected to flight test on the F-35 in 2010, with production engines available in 2012. This occurs during the fourth lot of F-35 aircraft production, which is very early in the overall F-35 production program. The F136 was the first F-35 engine to offer a single engine configuration for all three versions of the aircraft: STOVL for the US Marine Corps and UK Royal Navy, CTOL for the US Air Force, and the CV for the US Navy.
The F136 engine consists of a 3-stage fan, 5-stage compressor, a 3-stage low-pressure turbine section, single stage high-pressure turbine, and a radial augmentor. GE - Aviation, with responsibility for 60 percent of the F136 program, is developing the core compressor and coupled high-pressure/low-pressure turbine system components, controls and accessories, and the augmentor. Rolls-Royce, with 40 percent of the F136 program, is responsible for the front fan, combustor, stages 2 and 3 of the low-pressure turbine, and gearboxes. International participant countries are also contributing to the F136 through involvement in engine development and component manufacturing.
F136 Program History
Phase II of the Alternate Engine Program (AEP) was kicked off on 7 November 1996. Phase II consisted of the development and testing (in mid-2000) of a common F120 core that is suitable for both WSCs participating in the current phase, as well as Tech Mat tasks and Risk Reduction for the WSC alternate engine designs. Starting in 2001, after the final downselect for EMD, Phase III of the Alternate Engine Program developed the appropriate concept-unique low pressure components.
GE has developed a partnership with Allison Advanced Engine Company and Rolls-Royce, Plc. to develop the Alternate Engine. Rolls-Royce is responsible for development of the fan, applying their significant hollow fan blade experience. Allison (now Rolls-Royce Allison) is responsible for the combustor and low pressure turbine. GE will build the high pressure compressor and high pressure turbine.
On 1 December 1997, the JSF Program Management Advisory Group (PMAG) was chartered by the Assistant Secretary of the Navy for Research, Development, & Acquisition, Mr. John Douglass, in response to the 1998 Defense Authorization Act concerning the JSF AEP, Congress required DoD to certify that the AEP was fully funded and withheld 10% of the FY98 funding for JSF until that requirement was met. The senior-level PMAG was tasked to review the technical and programmatic issues of the AEP, determine its costs and benefits and report its findings. The PMAG determined that developing an alternate JSF engine had significant benefits in the areas of contractor responsiveness, industrial base, readiness and international benefits. Finding marginal, but not significant, benefits in the areas of cost savings and additional growth capabilities for the JSF production phase, the PMAG found that the AEP did not provide a benefit to EMD risk reduction without restructuring the program to conduct development concurrent with the P&W primary engine. The PMAG recommended that JSF proceed with the AEP as was currently planned.
The focus of the GE Phase II Core PDR on 14-16 January 1998, was on the preliminary design of the product core, defining the product core configuration, and identifying the test article configuration. The Government/WSC team reviewed the design status of each GE, Rolls-Royce Allison and Rolls-Royce core engine component to evaluate the progress, technical adequacy and risk mitigation, and to ensure the design met both Boeing and Lockheed Martin PWSC requirements.
A number of component tests were conducted in support of the alternate engine core development during the CDP, including diffuser rig, combustor single cup and 90º sector rig, YF120 turbine rig tests and others.
JSF development costs increased $1,033.5 million (+4.6%) as of December 31, 1998 from $22,329.0 million to $23,362.5 million, due primarily to the addition of funding for the alternate engine program in FY 2004-2011 (+$1,420.0 million). The increase was partially offset by a revision to the escalation indices (-$427.7 million).
The GE Rolls-Royce Fighter Engine Team achieved a major milestone on July 22 by successfully firing the F136 First Engine to Test. By 17 August 2004, the F136 engine had achieved 105 percent corrected fan speed transiently three times to acquire engine aeromechanics data. On 24 August 2004, the team completed F-35 Program Event No. 6, the Alternate Engine Readiness Review, in Fort Worth. This event demonstrated the readiness for the entry of the F136 Fighter Engine Team into SDD.
On October 14, 2004, the Acting Under Secretary of Defense (Acquisition, Technology, and Logistics) reviewed program progress since the Defense Acquisition Board review in June 2004. He authorized the joint program office (JPO) to award a transition contract on an incrementally funded basis for the F136 engine in a manner consistent with preparing for system development and demonstration.
The objective of the F136 Pre-SDD phase is to match engine design as closely as possible to that of the final aircraft configuration, thereby minimizing changes and keeping pace with evolving aircraft demands prior to entering SDD. The GE Rolls-Royce Fighter Engine Team (FET) F136 engine successfully completed all Phase III, Pre-SDD program requirements in April of 2005, on schedule and under cost. The first F136 CTOL engine was successfully tested for the first time on 22 July 2004. Testing on the first F136 STOVL propulsion system began on 10 February 2005. Both engines were delivered early and completed testing in April of 2005 accumulating over 200 hours of engine tests. The F136 anticipates the awarding of its multi-year SDD award contract in August of 2005.
The F136 team transitioned into the SDD phase of their program late in 2005. The F135 and F136 teams are working closely to develop common propulsion system components. This unique arrangement of "COOPETITION" was spawned by the Joint Strike Fighter Program's emphasis on affordability.
The first F136 CTOL engine was successfully tested for the first time on 22 July 2004. Testing on the first F136 STOVL propulsion system began on 10 February 2005. The F136 engines undergo testing at GE facilities in Peebles and Evendale.
By February 2006 the GE Rolls-Royce Fighter Engine Team LLC (FET) had successfully resumed testing its F136 Joint Strike Fighter engine. The engine ran in Short Take-Off Vertical Landing (STOVL) configuration at the GE-Aviation outdoor test facility located in Peebles, Ohio and marks the first milestone under its $2.4B System Design and Demonstration contract that was awarded in August of 2005.
Testing on the pre-SDD standard engine includes control system architecture development and additional analyses of performance and aeromechanical characteristics. The engine is fully equipped with STOVL common hardware lift-system which includes the Rolls-Royce LiftFan®, roll-posts and 3 Bearing Swivel Duct (3BSD). The engine was slated to run through April 2006 and a total of 100 hours of test are planned. In addition to full-scale development work, the F136 SDD phase includes the production and qualification of 14 engines, seven of which are for ground-test, and six plus one spare for flight-tests.
The first F136 engine is expected to test in mid-2008, but earlier risk-reduction tests are due to begin in 2006 using one of the Fighter Engine Team’s original pre-SDD development engines.
