A timely post.
As one of the few who has worked at both a military and now two civillian test pilot schools, I'd like to suggest that for an part of the business that lives and dies by objective, measurable criteria, why the flight test business insists on thinking that the military schools are the only ones 'approved' is a bit silly, at the least.
Why is there no objective means to ensure that you have the necessary skills and training? At least two of the military schools do not touch civil certification at all, at least one does nothing about structures and loads and flutter, and so on.
Graduation from a test pilot school will teach you something, but not everything you need to know to be good in this field. But some better criteria than just graduation is sorely needed.
(Note that the previous post listing the TP Schools did not include us - National Test Pilot School, yet we have been in business for over 20 years, and trained more engineers and pilots in the fundamentals of flight testing than probably all the other schools combined).
To carry this on a bit, we (at NTPS) continually see that the military schools are 'approved'. This implies there is an approval process, but what that process is cannot be found anywhere. Interesting to say the least.
Sorry for the rant, but we really should be better at this after 100 years of flying, don't you think?