IMO the most significant aircraft to the UK post 1945
Initially thought Chipmunk due to how many people were trained on it or had AEF, but then I thought about it...
The Harrier FRS1.
It was instrumental in winning the Falklands War, without it we would have lost. Although other aircraft such as the sole surviving Chinook BN did amazing work, they were not essential. All the other aircraft I have seen in the thread so far were just the type in service at the time, ie: Tornado. If we had another type in the same role (Phantom, F-16, Mirage 2000, F-15, etc.) the result would have been the same, but nothing else could have done what the little puffer jet did.
