By Andrea Shalal
WASHINGTON (Reuters) - Congressional auditors have joined the Pentagon's chief arms tester in raising concerns about the pace of development of software on Lockheed Martin Corp's new F-35 fighter jet and recommended the military's F-35 program office assess the plane's ability to integrate specific weapons by July.
A report by the Government Accountability Office, a congressional watchdog agency, said delays in software testing could increase development costs and might mean that the Marine Corps and other military services might not have all the weapons capabilities on their F-35 planes when they want to start using them in combat, according to sources briefed on the report.
Air Force Lieutenant General Chris Bogdan, who runs the F-35 for the Pentagon, acknowledged that software remained the No. 1 technical risk on the $392 billion weapons program. He said his office had adopted disciplined processes to deal with the complexity of writing, integrating and testing the millions of lines of software code being written for the new warplane.
Bogdan said the F-35 program agreed with the GAO's call for an assessment of the specific weapons capabilities that the F-35 would have when the Marine Corps and other military services want to start using it in combat, and already carefully monitored a series of software metrics.
The GAO report was the latest in a series that focused on software risks facing the Pentagon's biggest arms program. The program is nearly 70 percent over budget and years behind schedule, but U.S. officials say it is making steady progress.
The Pentagon's chief arms buyer, Frank Kendall, is also working on a report about software risks on the program.
Lockheed is developing three models of the new warplane for the United States and eight countries that funded its design: Britain, Australia, Canada, Denmark, Norway, Italy, Turkey and the Netherlands. Israel and Japan have also ordered jets.
Michael Gilmore, the Pentagon's director of operational testing and evaluation, warned in a January report that ongoing software, maintenance and reliability problems could delay the Marine Corps' plans to start using the F-35 jets by mid-2015.
His report forecast a possible 13-month delay in completing testing of the Block 2B software needed for the Marines to achieve an "initial operational capability" by that date.
The GAO report echoed those concerns, although it found the program was on a more stable footing.
U.S. defense officials and Lockheed say the program is on track to develop initial warfighting capability for the Marine Corps in 2015 and the Air Force in 2016.
Bogdan said there was more risk involved in getting the full warfighting capability done by 2018, when the Navy plans to start using its carrier variant in combat, since it was dependent on the successful delivery of the previous software.
"We are working relentlessly to reduce this risk by tracking software development daily and fixing issues as we find them so the military services and our international partners will receive the F-35's full warfighting capability," Bogdan said in a statement on the GAO report.
Lockheed said it had not seen the GAO report, but remained confident that it would complete flight testing this year of the software needed for the Marines to start using the jets in 2015.
Lockheed spokesman B.J. Bolling said the company had completed six of 15 weapons delivery tests required in the test plan for the Block 2B software, with the remaining nine tests to be completed in coming months.
Bolling said Gilmore's forecast of a 13-month delay also assumed a 120-percent growth in the number of test points in 2014, the same rate seen in 2013. But the 2013 growth was due largely to work on the complex helmet worn by F-35 pilots, which would not be required in 2014, he said.
One U.S. Marine Corps official said the service's F-35 jets were flying more often and carrying out increased sorties, which was giving Marine Corps pilots more experience.
"We're generally optimistic," said the official. "We certainly expect to meet our targets."
(Editing by Mohammad Zargham)