F35 JSF Actualité

The Pratt & Whitney F135 engine powering the Lockheed Martin F-35B short takeoff and vertical landing (STOVL) variant has exceeded the thrust requirement during hover pit tests leading up to airborne testing.

Lockheed’s first STOVL prototype – dubbed BF-1 – has demonstrated 41,100 pounds of thrust in vertical mode. The new benchmark represents a 1.3% improvement over the rebaselined thrust requirement, and a nearly 5.4% increase over the programme’s original requirement.

That extra margin still provides an “excellent” buffer in case the F-35B’s customers need an additional boost of vertical thrust above the current requirement, which is 40,550 pounds.

In 2004, Pratt & Whitney demonstrated an engine that could meet the original requirement of 39,000 pounds of vertical thrust. That requirement became outdated after the F-35B experience a major redesign to offset about 5,000 pounds of extra weight accumulated during the design phase.
A shaft-driven lift fan manufactured by Rolls-Royce powers the F135 engine in vertical mode.

The hover pit tests are among the last steps before BF-1 can attempt to return to flight after a nearly year-long hiatus and transition from conventional flight to vertical landing mode.

Lockheed says it has also demonstrated several key test points before the hover pit tests, including inlet pressure recovery, pitching moment, rolling and yawing moment, effective vector angles of the exhaust and control-input response time.

Australia plans to buy up to 100 Lockheed Martin F-35 Joint Strike Fighters (below) as part of a comprehensive plan to revamp its defence force capabilities and prepare for a changing security environment in the Asia Pacific over the next 20 years.

The Royal Australian Air Force, he adds, will be “far more versatile and far more capable” with a “wider range of advanced surveillance, transport and air combat options” as a result. Much of this hinges on the acquisition of the F-35s, which have been confirmed as the backbone of the RAAF’s air strike capability in the future.

Canberra is likely to go ahead with the procurement of no fewer than 72 F-35s in the third quarter of 2009, when the aircraft’s delivery schedule will become clearer. A fourth squadron will bought later based on the timing of the withdrawal of the country’s fleet of 24 Boeing F/A-18F Super Hornets that will enter into service from later this year. Australia could convert half of the Super Hornets into E/A-18G Growlers depending on future strategic imperatives.

.....airlift capability with Australia buying another two Lockheed Martin C-130Js,.....

.....troubled EADS KC-30A multi-role tanker transport programme is on track and that the first of five aircraft will be in service soon.

Eight new maritime patrol aircraft ....to provide advanced antisubmarine, anti-surface warfare, and sophisticated maritime search capabilities. These will be supplemented by seven new high-altitude, long-endurance unmanned aerial vehicles to replace the Lockheed Martin AP-3C Orions.

Despite ongoing problems with the platform, Australia reaffirmed its commitment to the Boeing 737-based Wedgetail airborne early warning & control (AEW&C) aircraft.

The navy will get another six new NH Industries NH-90 multi-role helicopters to replace its Westland Sea King fleet, and there will be “added urgency” to buy at least 24 new naval combat helicopters.

Additional emphasis will be placed on increasing the army’s unmanned aerial vehicle capabilities, and the service will also replace its fleet of six Boeing CH-47D Chinook helicopters with a new fleet of seven Boeing CH-47F aircraft. “With a lift capacity of about three times that of a [Sikorsky] Blackhawk, the Chinook is a critical component of the Army Aviation fleet, providing support ranging from tactical and intra-theatre battlefield lift for our soldiers to regional humanitarian assistance” Mr Fitzgibbon said.

Lockheed Martin has made what is being described by sources as a "very general" offer to have Israel Aerospace Industries manufacture fuselage parts for it F-35 Joint Strike Fighter as part of its effort to encourage Israel to buy the aircraft as early as 2014.
The Israeli air force has expressed its intention to purchase 25 F-35s with options for another 50, but the $135 million unit price for aircraft in its configuration has put the timing of the acquisition in question.
In February 2002 Israel joined the JSF programme as a security co-operation participant, a relatively low status giving it some programme information.
The air force and Israeli defence and aerospace industries are attempting through a special liaison office in Washington to influence the final configuration of F-35s for Israel, but their efforts have so far had little effect.

War of Words Erupts Over F-35 Engines

Jul 17, 2009



Guy Norris/Los Angeles



The future of the Joint Strike Fighter alternate engine program reaches a critical juncture this week when the U.S. Senate is expected to vote on whether to follow through on its earmarking for the General Electric Rolls-Royce F136 in the 2010 defense budget. The second F135-powered F-35B flew for a second time on July 13. If it survives, the first F136-powered F-35 will not fly for at least two years.Credit: STEVE SHANK

It is a vote engine industry insiders say is too close to call, and which could finally make or break the long-running alternate F136 engine campaign. Although losing the full Senate vote would not directly end the program, both sides of the engine debate recognize that coming back from a "no vote" this time would not be easy.

Pratt & Whitney--stung by the loss of two F135 engines in the program cuts this year and facing a similar outcome in 2010 as a result of funding for the F136--is posturing to defend its corner more aggressively than ever before. The company, which also faces the simultaneous threat of losing funding for the final batch of F119-powered Lockheed Martin F-22s, is being bullish over its latest F135 program achievements to date and positive over its cost-cutting plans for the engine.

Pratt's position is strongly backed by the White House, which last week threatened to veto the defense bill if it includes spending on the F136 that Defense Secretary Robert Gates earlier identified as wasteful. A bluntly worded White House statement says "the administration strongly objects to the addition of $438.9 million for development of the alternative engine program. The administration also objects to provisions of the bill that mandate an alternative engine program for the JSF."

Facing its hardest fight for survival yet, the embattled General Electric/Rolls-Royce Fighter Engine Team was buoyed by figures presented by the House Armed Services Committee, which appears to support one of the F136 team's principal arguments that competition will help keep costs in check.

In a statement, the committee says "the F-35 program manager has reported an increase of approximately 38-43% in F135 engine procurement cost estimates between December 2005 and December 2008, in the annual selected acquisition reports for the F-35C and F-35A variants. Between December 2005 and December 2008, engine procurement cost estimates for the F-35B have grown approximately 47%, but the F-35B engine procurement cost growth is attributable to both the F135 engine and the F-35B's lift fan."

But Warren Boley, Pratt & Whitney vice president for F135 programs, says "the numbers referenced represent future cost projections over the total program (30 years) if we do not achieve 'learned-out' cost. However, with the aggressive steps we are currently taking, and our experience in significantly reducing the cost of the F119 as it was learned out, we believe we have the same opportunities for cost reduction with the F135."

Cost savings on the F135, Boley says, will include lessons learned from the test program, lean production initiatives, production changes in the assembly shop and reductions in rework and scrap. "We know what the F-35 Joint Program Office needs, and we know we can get it because we did it on the F119."

The learned-out cost reduction on the F119 was 30%, and "we see those opportunities" for the F135, Boley notes. The projected costs are targeted for the 250th production engine scheduled for 2014, and will hold for the bulk of the program. "That's a significant cost saving on 1,500-3,000 engines," he says. Pratt is currently assembling the initial production configuration units and will deliver the first seven to Lockheed Martin in the fourth quarter of this year.

Despite the House committee's main focus on F135 costs, the F136 team also received a significant boost from the panel for keeping its costs stable. Saying the F136 "has not experienced any cost growth since its inception," it notes the $411-million pre-EMD [equal to system development and demonstration, or SDD] contract cost remained steady, while the main $2.48-billion EMD deal signed in 2005 "has been stable since contract award." In a hard-hitting summary, it adds that, "given the F135 development and procurement cost increases, the committee is perplexed by the department's decisions over the past three years to not include an F-35 competitive propulsion system program in its budget requests."

However, Pratt proponents point out that cost and schedule are easier to maintain in a limited development effort such as the early pre-SDD phases of the F136, and cite indications of growing slippages in the alternate engine schedule. The F136 team acknowledged at the recent Paris air show that the date for the first flight-test engine has slid to early 2011 from 2010, but says this reflects schedule adjustments by Lockheed Martin rather than any engine development issues.

The F136 team does confirm, however, that funding shortages and shifting program schedules have forced it to reprioritize initial service release (ISR) targets. "We've moved it up for CTOL [conventional takeoff and landing] to March 2012, and Stovl [short takeoff and vertical landing] has gone out to the right to around March 2013," says the team. The change to the Stovl target reflects the fact that no F136-powered F-35s are earmarked for the earlier production Lot 4 batch around that time. "They didn't need it until 2013, and we didn't have the money anyway," it adds.

The GE-Rolls team also says budget shortfalls have forced it to push back the initial flight readiness (IFR) milestones for the CTOL engine by three months, and IFR for Stovl by four months. The F136 team first met for IFR reviews in May. The meetings coincided with the resumption of tests on F136 Engine 004 following modifications to the bearing system.

Despite the hold-up, the F136 team insists that the schedule remains on track. Unlike the Pratt test schedule on the first SDD F135, which encompassed some 420 hr. of runs, it says the requirement for the GE-Rolls engine was smaller because the 700 hr. of runs during the pre-SDD phase included many aspects of the later configuration. Engine 004, the first SDD F136 to test, was never intended to exceed 100 hr. before the rebuild, it adds.

Photo credit: USAF

Lockheed Martin has restarted the countdown to the first vertical landing by the F-35B Joint Strike Fighter, with aircraft BF-1 returning to flight on Sept. 4 with an hour-long test sortie.

The first short takeoff and vertical landing (STOVL) test aircraft, BF-1 had been on the ground for an extended period to incorporate modifications following earlier flight and hover-pit tests.

Return to flight following modification was delayed by a number of glitches including wiring issues, fixed by rerigging the weapons-bay doors, and problems with the integrated power package, overcome by installing a newer unit.

BF-1 will conduct a series of flights in the Fort Worth, Texas, area, opening the STOVL doors and engaging the lift fan in flight to check out flight-control software changes resulting from earlier doors-open test flights.

Plans then call for BF-1 to ferry to the U.S. Navy test center at Naval Air Station Patuxent River, Md., to continue powered-lift STOVL “build-down” testing until the first vertical landing, now expected in October.

The second STOVL aircraft, BF-2, completed probe-and-drogue aerial refueling flight-testing to clear the way for ferry flights and has been down for final finishes. The aircraft is due on the hover pit this week as a prelude to returning to flight.

BF-3, the third STOVL aircraft, is in extended ground testing, so the next F-35s scheduled to fly are the first production-representative conventional takeoff and landing aircraft, AF-1, and BF-04, the fourth and final STOVL test aircraft.

Pratt & Whitney investigates new fan blade glitch for F135
By Stephen Trimble

Pratt & Whitney is investigating how a "handful" of fan blade tips damaged an F135 engine during a ground test simulating the Lockheed Martin F-35's engine performance at supersonic speeds.

The programme's latest technical issue comes amidst a heated debate between the White House and Congress about continuing to fund the F135's rival engine - the General Electric/Rolls-Royce F136.

The new problem also comes amidst a Pentagon-directed cost review for the F135 and the return-to-flight of Lockheed's first short-take-off-and-vertical-landing (STOVL) prototype, which was grounded a year ago to fix a blade fatigue issue discovered in P&W's design.

The F-35 Joint Programme Office estimates it will take five days to identify the cause and corrective action for the F135's latest glitch, says a P&W programme expert who asked to remain anonymous.

Flight tests for the Lockheed F-35 fleet are continuing on schedule despite the investigation, the expert says. The cost to fix the problem is unknown until the root cause is identified, the expert adds.

Engineers discovered the problem when they noticed parts flying out of the tail pipe for a convetional-takeoff-and-landing (CTOL) version of the F135 engine, the expert says.

Upon inspection, the errant parts were traced to several missing fan blade tips that somehow broke off. The parts were ingested into the compressor, which also sustained damaged in the first and second stages, P&W's expert says. The combustor and turbine stages escaped harm from the flying debris.

Besides the fan blades, P&W also intends to retrieve an unidentified part found on the bottom of the engine bay between the fan and compressor stages, the expert says.

The blade problem occurred during the fifth hour of an 11hr series of ground tests simulating the F-35's engine performance at supersonic speed, the expert says. Although the investigation is ongoing, the supersonic acceleration is not considered to be a direct cause of the blade problem.

"The testing that was actually being done is not thought to be primarily contributory," the expert says. P&W is considering other possible causes such as foreign object debris and the structural design of the blades.

P&W officials emphasized that the incident occurred after the engine completed 2,455 cycles, simulating 8 years of operational service life. That should give P&W several years to develop and install a fix for the problem, the expert adds.

The Department of Defense wants to cancel the F136 and make P&W the sole engine supplier for the F-35 programme, arguing that the costs to develop an alternate engine out weight certain benefits such as supplier competition and reducing the risk of dependence on the F135 to power thousands of tactical fighters.

But some in Congress have pushed to overturn the DOD's decision. The House of Representatives has approved a version of the defence spending bill that restores full funding for the F136, but Senate appropriators have agreed to cancel the programme. The two houses decide the issue during upcoming conference negotiations on a final spending bill.

Fate Of Second F-35 Engine Nears
Sep 11, 2009

Graham Warwick graham_warwick@aviationweek.com


The fate of the F136 alternate engine for the F-35 Joint Strike Fighter will be the central issue of debate when House and Senate negotiators meet in conference late this month or early in October to finalize the fiscal 2010 U.S. defense budget.

The Senate appropriations committee set the stage for the showdown on Sept. 10 when it approved the defense subcommittee's mark-up of the bill, which omits money for the General Electric/Rolls-Royce F136 engine but fully funds F-35 procurement.

The House appropriations committee had previously added $560 million to their mark-up to fund continued development and initial procurement of the F136, while cutting two aircraft from the Pentagon's request for 30 F-35s to save $538 million.

The standoff has sparked a frenzy of lobbying from both sides, with Pratt & Whitney striving to defend its position as primary and only supplier of JSF engines. With the House firmly backing a second engine, the focus is on the Senate, which has so far heeded threats from the Obama administration to veto the defense budget if it funds the second engine at the expense of the baseline F-35 program.

The JSF engine is not the only area of disagreement conferees face, providing plenty of room for horse-trading. Both sides bowed to administration demands that F-22 procurement be terminated, but they defied the Pentagon in providing funds for more C-17s to keep the line open: the Senate adding 10 and House just three.

The House also added $400 million to make five already-built VH-71 Increment 1 presidential helicopters operational, while the Senate supported the administration's decision to terminate the program and provided money to begin a new competition.

Both sides supported the Pentagon's cancellation of the CSAR-X combat search-and-rescue helicopter program, and added money to procure new HH-60Ms for the U.S. Air Force, with the House adding five and Senate two.

While the Senate funded the administration's requests for procurement of nine F/A-18E/Fs, 22 EA-18Gs and two E-2Ds for the U.S. Navy, the House added money for an additional nine F/A-18E/Fs and one more E-2D. Both cut procurement of UH-1Ys and AH-1Zs for the U.S. Marine Corps -- the House by four and Senate by six -- citing operational readiness concerns.

Additionally, the House trimmed the number of CH-47s for the U.S. Army, citing earlier overprocurement, and cut funding of RQ-4 Global Hawk unmanned aircraft for the Air Force to just two, from five, where the Senate fully funded the Pentagon's requests.

FORT WORTH, Texas | A short takeoff/vertical landing (STOVL) variant of the Lockheed Martin F-35 Lightning II stealth fighter has become the first F-35 to complete an aerial refueling test using the Navy- and Marine Corps-style probe-and-drogue refueling system. Thursday's successful mission is the first in a short series of tests that will clear the STOVL F-35B variant for extended-range flights, particularly to its primary test site at Naval Air Station Patuxent River, Md.