The F-35 Joint Strike Fighter program is the most expensive procurement program in Pentagon history. It’s been plagued by schedule delays, gross cost overruns, and a slew of underwhelming performance reviews. Last month the Air Force declared its variant “ready for combat,” and most press reports lauded this as a signal that the program had turned a corner. But a memo issued from the Pentagon’s top testing official, based largely upon the Air Force’s own test data, showed that the Air Force’s declaration was wildly premature.