Air Force’s F-35 fighter, due to form the bulk of future tactical air power and to be bought by allies, may be able to fly only 85 percent as far as originally projected, a Pentagon document shows.
The radar-evading aircraft’s “A” model is currently estimated to have a combat mission radius of 584 nautical miles, just short of the required 590 nautical miles, a December 31-dated report to Congress said.
Program officials originally estimated that the F-35A would be able to hit targets 690 nautical miles away, unrefueled, or 15 percent more than now, the Department of Defense’s “Selected Acquisition Report” showed, Reuters reports.
The current combat radius prediction is based on estimates of the amount of compressed air diverted from the engine to run onboard systems as well on aircraft performance and fuel capacity that are not yet fully known, the report said.
“Current estimates have built-in margin that may not be realized,” it said, adding that aircraft modifications were possible to add fuel capacity that would boost the range.
The F-35 family of fighters is the Pentagon’s costliest arms purchase, projected to total some $382 billion over the coming two decades for 2,443 aircraft. Three models are being built for the U.S. Air Force, Navy, Marine Corps and allied countries by Lockheed Martin Corp.
The Pentagon report appeared first on the Dew Line, an aerospace blog.
Lockheed Martin, the Pentagon’s No. 1 supplier by sales, did not respond to a request for comment, nor did the military’s F-35 joint program office.
The Air Force is scheduled to buy 1,763 of the conventional takeoff and landing “A” models to replace F-16s and A-10s and to complement the F-22, the premier U.S. dogfighter.
F-35 early-production models are powered by the F135 engine built by Pratt & Whitney, a unit of United Technologies Corp.
As a “stealth” aircraft meant to appear as small as a bird on enemy radar, the F-35 carries no external fuel tanks and all of its weapons are carried inside a bomb bay.
Even as the F-35A’s combat range may be shrinking, the costs for F-35 early-production models have been creeping up, straining a program for which affordability is meant to be a hallmark.
Range estimates have been cut for all three F-35 versions because of a growing expectation that they will need to “suck a little bit more power out of the engine” to run internal systems, including cooling, said Dave Majumdar, a pilot who is air warfare correspondent for Defense News, a trade publication. He said the “A” model had been affected the most.
Any engine-related performance questions could boost efforts by some U.S. lawmakers to revive a competitive engine program formally canceled last month by the Pentagon as unnecessary and wasteful.
“It certainly stirs the pot,” said Winslow Wheeler, an F-35 critic at the private Center for Defense Information, citing what he called “more cost, less performance” of the aircraft.
The U.S. House of Representatives’ Armed Services Committee voted 54-5 on Wednesday to require the Pentagon to let General Electric Co and Rolls-Royce Group Plc continue their joint development of an alternate engine for the F-35, as long as it was done at no cost to the government.
Eight countries have joined the United States to co-develop the jet — Britain, Italy, Netherlands, Turkey, Canada, Australia, Denmark and Norway.
Competitors for foreign sales include Saab’s Gripen, Dassault’s Rafale, Russia’s MiG-35 and Sukhoi Su-35 as well as the Eurofighter Typhoon made by a consortium of British, German, Italian and Spanish companies.
Another competitor is the F/A-18E/F Super Hornet built by Boeing Co, which lists a combat radius of 500-plus nautical miles carrying three 480-gallon external tanks and four 1,000-pound bombs.