The French may have spin tested their versions at Istres but UK also did spin testing. I wasn't part of that team but did see the extensive work done in prep for the tests. Jag was fitted with usual antispin chute and instrumentation. Special care was taken in build up because of known possibility of a/c entering a fast-flat spin that was likely unrecoverable. Special spin panel fitted with direction of spin lights and a very bright light to signal below minimum altitude - eject now. Tests were carried out over Yorkshire Moors area in 74/75