* U.S. civilian defense workers began furloughs on July 8
* Pentagon seeking to mitigate effect on F-35 testing
By Andrea Shalal-Esa
WASHINGTON, July 8 (Reuters) - Flight testing of Lockheed Martin Corp's new F-35 fighter jet will fall short of planned totals for the year due to budget cuts that will keep the Pentagon's civilian workers off their jobs for 11 days, a top U.S. Navy official told Reuters on Monday.
"It's going to fall short because we're going to lose a day a week, roughly," Sean Stackley, assistant Navy secretary for research, development and acquisition, said in an interview.
Stackley said the Pentagon's F-35 program office was trying to mitigate the impact of the furloughs on civilian workers of one day each week for the rest of the fiscal year. It was not yet clear how many overtime and weekend hours could be used to offset other missed workdays, he said
The F-35 project, the Pentagon's biggest weapons program, was already scrambling to make up for several weeks of flight testing that had to be deferred due to two separate flight grounding actions earlier this year. The U.S. military is keen to complete flight testing of the already delayed F-35 program so that it can begin to use the new jets for military operations.
Civilian defense workers across the United States began taking unpaid leave on Monday as part of an austerity plan that is expected to save $1.8 billion through Sept. 30, the end of the 2013 fiscal year. The furloughs are part of nearly $37 billion in automatic across-the-board budget cuts that hit the Pentagon this year as part of a process known as sequestration that is aimed at curbing the U.S. government's nearly trillion-dollar deficit.
Stackley said it was not clear yet exactly what the impact of the civilian furloughs would be on the already delayed $392 billion F-35 program, but said flight testing for the rest of the year would likely be reduced by at least 20 percent.
"We will be doing well to contain the impact of sequestration to a 20 percent loss of flight hours for the balance of the year," Stackley said.
He said F-35 program officials would get a better sense of the impact on flight testing this week since the furloughs were just taking effect.
Other factors such as weather conditions can affect the schedule for flight testing of new warplanes.
Lockheed is building three models of the new warplanes for the U.S. military services and eight international partners: Britain, Australia, Canada, Turkey, Italy, Denmark, Norway, and the Netherlands. Israel and Japan have also ordered the jets.
Lockheed's chief financial officer, Bruce Tanner, told Reuters in an interview in May that F-35 flight testing could be affected, noting that civilian government workers played a big role in supporting such tests and other critical work.