I'm surprised we haven't leveraged support from the Army
Wasn't the thing paid for in the first place by chopping hordes of armour, with ASTOR 'force multiplying' the remnants of the tank fleet? If so it would be exceptionally cheeky to go to the Army for yet more leverage
Personally I'm yet to be convinced that we need a land-battle reconnaissance radar enough to warrant chopping anything else.
Edited to add: I found
this interesting history of the CASTOR / ASTOR projects, in which I particularly liked this line:
[MOD] ruled out the E-8C J-STAR, as it could only operate at around 42,000ft and anyway the MOD were not keen to acquire such an old and essentially obsolete airframe
Bearing in mind this was twenty years ago, if it's true then it's an absolute classic, just like the RJ!
