Looking at the A-7 designations, I think that there's something missing. Namely, the A-7F and A-7J
'
But', I hear you say, '
that was the transonic version tested in the late 1980s.' Yes, it was. But that was out of sequence.
You see, after the US Navy's A-7E, the next available designation was A-7F. But instead, we got:
- No A-7F until 1985
- The abortive A-7G for Switzerland in 1972
- The TA-7H prototype two-seater, later redesignated TA-7E
- The A-7E for Greece
- No A-7J
- The USAF two-seat A-7K
- The USN electronic aggressor EA-7L
Yes, the 'A-7H' for Greece is claimed to come from 'Hellas'. But I don't believe any such equivalent (or precedent) exists for Switzerland to receive the 'G' suffix. And, moreover, the A-7K and EA-7L form part of this sequence. Which means the A-7F and A-7J were either skipped for some reason, or assigned to a project that never materialised.
It's a distinct possibility that the A-7J was skipped to avoid confusion with the use of 'J' for Japan. But 'K' wasn't skipped for the United Kingdom, and there have been plenty of other J-suffix aircraft, so that's not conclusive. Skipping 'F', though, doesn't have any obvious explanation.
Looking at the timelines, any abandoned A-7F would likely date between about 1969 and 1972, while the A-7J would date between 1975 and 1979.