Pentagon sees some risk of delay in F-35 software WASHINGTON (Reuters) - The Pentagon's F-35 Joint Strike Fighter program on Wednesday said there was "some risk" that software being developed by Lockheed Martin Corp for the Air Force version of the new fighter plane would be delayed beyond late 2017. Air Force Lieutenant General Christopher Bogdan, the Pentagon's program executive officer for the F-35 program, said work on the software known as Block 3F was the biggest risk currently facing the $396 billion F-35 program, the Pentagon's largest weapons program. He said he would have a better idea when work would be completed on the software after a critical design review scheduled to be completed this summer. Any delay in work on the Block 3F software could delay the initial operational use of the new fighter plane by the Air Force. The Marine Corps plans to start using the new fighter jets around mid-2015 using a slightly less capable version of the software known as Block 2B. Reporting by Andrea Shalal-Esa; Editing by Gary Hill