What can I say, this program has only been around for more than ¼ century, and that is just not enough time:

The F-35 Joint Strike Fighter full-rate production decision, which is slated for December, may be put off for up to 13 months because of delays with integrating the Joint Simulation Environment (JSE).

Pentagon chief weapons buyer Ellen Lord signed a program deviation report this week that documented the expected threshold breach in the milestone C full-rate production decision, she told reporters Oct. 18 during a Pentagon briefing.

“What this is a result of, and I follow this very carefully, is the fact that we are not making as quick progress with the Joint Simulation Environment integration of the F-35 into it,” Lord said. Integrating the JSE with the F-35 is “critical” for initial operational test and evaluation, she said. The JSE projects characteristics like weather, geography and range that allows test pilots to use the jet’s full capabilities against the full range of required threats and scenarios.

This simulator is not a pilot simulator.  It’s an software development environment to validate that the software actually works.

It doesn’t work.