Steven P. McNicoll wrote:
The speculation is rather academic anyway, because the was a valid reason
why the JSF demonstrators used [snip] non-sequential
numbers.


That valid reason being the assignment of the intervening numbers, X-33
and X-34, to other projects.

.... and that the X-32 slot, originally assigned to the JAST (Joint Advanced
Strike Technology) program, was taken over by the JSF program. Although
JSF's objectives were much different than JAST's (develop - in the long
term - an operational aircraft vs. "only" technology demonstration), JSF
was effectively a continuation of JAST by another name. Therefore keeping
the allocated vehicle designation was a logical decision, even if the JSF
demonstrator(s) wouldn't be _purely_ experimental machines. If JSF hadn't
had JAST as a precursor program, it's IMHO much more likely the aircraft
would have been designated F-24/25 from the beginning.

Andreas