The Nimrod that didn't work!!
Nimrod AEW did just evolve - it was not meant to be built. As I understand, when the decision to split from the NATO AEW Component was taken in the early seventies (24 E-3A at Brize or Fairford) and we decided to go it alone, everybody in the know accepted that the UK would buy 6 x E-3A as our contribution to the NAEWF. However union power was rife at the time, so a small amount of money was dangled in front of the UK manufacturers to come up with a home-built solution before we bought the American system. GEC pocketed their share of the money, rolled out a Comet fitted with a bulbous nose radar used to test the "Blue Circle" FMICW radar which was being developed for the (then) F2, and stated that this was the best AEW platform in the world. This Sop to Union power was fine until a change of Government brought Harold Wilson to power. The result was "we are not buying from abroad - we will buy British". GEC was left with a contract, no solution and egg on their faces - hence the AEW radar with absolutely no performance. Any Sqn Sh*g on day 2 of a radar course would realise that the parameters chosen for the radar would not be suitable (Low PRF, inappropriate clutter notch etc).
Those of use who flew both AEW3 and E-3 certainly know which we would rather have had. A very sad and state of affairs for our aerospace industry!!