By Idrees Ali and Andrea Shalal
WASHINGTON (Reuters) - Lockheed Martin Corp's $391 billion F-35 stealth fighter jet program has made steady improvements in cost, schedule and technical performance over the past year, but still faces delays in software development and a complex computer-based logistics system, Pentagon officials said on Wednesday.
The F-35 program chief, Air Force Lieutenant General Chris Bogdan, gave members of a House Armed Services subcommittee a detailed account of "the good, the bad and the ugly" about the Pentagon's largest weapons program. But Bogdan said he remained confident that current and future problems could be resolved.
Lockheed is developing three models of the jet for the U.S. military and nine countries that have already placed orders: Britain, Italy, Turkey, the Netherlands, Norway, Australia, Japan, Israel and South Korea.
Bogdan told reporters the Pentagon's projected cost of developing and building the jets had dropped by $7.5 billion since last year, due to concerted cost-cutting efforts.
Further reductions were expected once the Pentagon finalizes $15 billion in contracts with Lockheed for the next two batches of jets in March and April, Bogdan said.
Development of software for the jets remains a concern, he said, with the jet's final software, known as Block 3F, running about four months late since testing of earlier software took longer than planned. That delay is several months shorter than projected last year, and should not affect the U.S. Navy's plans to field an initial operating squadron of jets in 2018, he said.
Testing was planned in coming weeks for a new version of the software written to correct a glitch that causes the jet's radar systems to restart once every four hours of flying. The goal is to improve the span to once in every eight to 10 flying hours.
Michael Gilmore, the Pentagon's chief weapons tester, said the issue was disturbing since the previous Block 2B software had seen a sensor restart only once every 20 hours.
He said the jet would not be ready for operational testing until mid-2018, a year later than expected, due to the various issues. He said more than 300 planes would have been produced by the end of fiscal 2017, when that testing is now due to start.
Bogdan said the program was also correcting issues with pressurization of the jet's fuel tanks, cracks found in the Navy's F-35C carrier variant after nearly 14,000 flight hours, and a ground-based computer system that reads the encrypted mission and maintenance data carried to and from the plane.
(Reporting by Idrees Ali and Andrea Shalal; Editing by James Dalgleish and Kenneth Maxwell)