| While it is fun to talk about aircraft performance, it's hard to get away from the consideration of the aircraft as part of a "weapons" or "air defense" system (SAGE ... NTDS ... radars / missiles).
For fleet air defense, it has to be the F-4J / FG. Mk1 Phantom with pulse doppler radar (AWG-10/ APG-59 in the -J and the AWG-11 in the FG. Mk1). Aircraft: unsurpassed combination of performance and BVR missiles (4-6 Sparrows)
System: supported by NTDS
Then there is the Mach 3 YF-12A with the first demonstrated "look-down, shoot-down" capability (ASG-18 / AIM-47 combo). Too bad it never reached operational service.
A Pakistani upgraded J-6 has a thrust-to-weight ratio of 0.9, three NR-30 (heavier shell and higher mv/ flatter trajectory than DEFA and ADEN) directed by a radar ranging/ lead computing gun-sight, as well as AIM-9 ... That's pretty potent! Its powered controls allow it to turn at high speeds - something the MiG-17F - itself a strong contender - couldn't do.
Nevertheless, I would go with a weird one, Harrier GR1 that entered service in 1969. Granted it was 1970 when USMC pioneered the use of VIFF (and it took a bit of modification to the nozzles to optimize) but that "threw the rule book out the window" with the extraordinary things it could do ... The GR1 had the high thrust-to-weight ratio and the ability to do VIFF plus two 30mm ADEN and a good gunsight. That makes it my choice for "pre-1970" ... (I suppose you would have to bend the rules a bit to allow the 1970 version that was really optimized - the USMC AV-8A version carrying the high performance AIM-9D Sidewinder with a cooled seeker.)
If "ground attack" is taken to mean close air support, then an Israeli modified Skyhawk would be amongst the best - all things being equal with its USN/USMC cousins, the 30mm DEFA gives it the edge.
For all weather strike, the A-6A with DIANE is hard to beat for its ability to accurately hit targets in appalling weather. F-111A with TFR would have gotten the nod but for the fact that its deficiencies were not corrected until the 1970's. For good bombing accuracy and that all important ability to out-run a lot of interceptors at low altitude, the Buccaneer deserves a mention ... |