By Andrea Shalal
WASHINGTON (Reuters) - U.S. Marine Corps Commandant General Joseph Dunford has declared an initial squadron of 10 Lockheed Martin Corp F-35B fighter jets ready for combat, marking a key milestone for the Pentagon's biggest weapons program, the Pentagon said on Friday.
The decision makes the Marines the first U.S. military service to declare an "initial operational capability" for the stealth supersonic F-35 fighter under the $391 billion arms program that first kicked off in 2001.
Lockheed is developing three models of the jet, also known as the Joint Strike Fighter, or Lightning II.
Early technical challenges delayed the Marines' move by three years from its original target. But U.S. officials say the F-35 program has been meeting its schedule and lowering costs for the past five years.
The Marine Corps' F-35B model can take off from warships and aircraft carriers and land like a helicopter. The Marines plan to buy 420 F-35B-model and C-model jets in total.
"The F-35B's ability to conduct operations from expeditionary airstrips or sea-based carriers provides our nation with its first fifth-generation strike fighter, which will transform the way we fight and win," Dunford, who was confirmed by the Senate this week to become the next chairman of the Joint Chiefs of Staff, said in a statement.
Deputy Commandant for Aviation Lieutenant General Jon Davis said the squadron met all the requirements for the declaration during a recent operational readiness review. But he called for vigilance to ensure sufficient training and spare parts were available for sustained combat operations.
Davis said he also hoped to boost the new planes' readiness rate beyond the current fleet rate of 70 to 75 percent.
The Marine Corps plans to send the first squadron of F-35B jets to Iwakuni, Japan, in January 2017, but Friday's declaration means they could respond to a crisis anywhere in the world.
Defense Undersecretary Frank Kendall and other officials underscored the need to continue driving down the price of the new jets, and wrap up work on new software needed to equip them with more weapons and sensors.
Each F-35B included in the last production lot negotiated by the Pentagon with Lockheed and engine maker Pratt & Whitney, a unit of United Technologies Corp, cost $134 million. The A- and C- models cost $108 million and $129 million, respectively.
Senate Armed Services Committee Chairman John McCain called the Marine Corps move an "important milestone," but underscored his concerns about the capability and reliability of the jets.
“The Joint Strike Fighter is the most expensive weapons system in history, and we must learn the lessons of past failures to ensure American aviators can safely and effectively perform their missions, and that taxpayer dollars are spent efficiently," he said in a statement.
Davis told reporters the jets did well during the recent review, both in targeting and "killing" enemy aircraft and providing close air support for troops on the ground.
He said pilots were even able to carry out an armed reconnaissance mission in a "very high threat" environment to which older fourth-generation fighter jets like the Boeing Co F/A-18 and AV-8B Harrier had not been subjected.
The Marine Corps opted to start using the F-35B jets with an early version of software called Block 2B. Software still being tested will allow the warplanes to carry more weapons and integrate full night-vision capability.
Admiral John Richardson, President Barack Obama's nominee for chief of naval operations, told lawmakers on Thursday that he would take a hard look at the Navy's plans to buy 340 F-35C-model fighter jets, which have longer wings and can land on aircraft carriers.
(Reporting by Andrea Shalal; Editing by Dan Grebler)