Issues with the plane have included lags in software development that make it unsuitable for combat; cracks in the engine; and flaws in the million-dollar high-tech helmet that is supposed to tell pilots what is going on around them.

A big part of the problem with the F-35 is the “buy first, fly later” approach to developing it. The Pentagon’s chief weapons buyer, Frank Kendall, has described this approach as “acquisition malpractice,” and promised to do better. But the fire at Eglin is just the latest indication that the program is far from being “back on track.”

The real problem with the F-35 is not how it’s being built; it’s that anyone at the Pentagon thought it would work in the first place. The F-35 was conceived in the 1990s under the name Joint Advanced Strike Technology. The idea was that versions of the plane would be built for the Air Force, the Navy and the Marines, resulting in a large production run that would increase economies of scale and keep costs down.