More F-35 Delays Predicted

Less than two years after a new Pentagon leadership team adopted a new integrated master schedule (IMS) for the F-35 Joint Strike Fighter program—which in 2010 plans was to have been declared operational by now—the latest plan is at risk, according to the Defense Department's chief weapons-tester.
Software required to meet the Marine Corps' limited initial operating capability (IOC) date is already expected to be eight months late. Radar and electro-optical system snags have delayed weapons integration, consuming all the margin built into weapons testing. Buffet and transonic wing-drop “continue to be a concern to achieving operational combat capability.”
The root of the software delays is that the program has been forced to add tests at a rate that more than offsets better-than-scheduled testing performance. The main causes, are the helmet-mounted display system (HMDS) and regression testing—which ensure that changes have not caused problems in areas previously vetted.
aviationweek