Originally Posted by
typerated
Interesting regarding the Mirage2000. I thought when it came out it was ahead of it's time. Not in the use of a Delta though!
But in it's performance being optimised for the top right hand corner of the envelope.
Speaking of the "top right hand corner of the envelope": the North American F-108 Rapier was a Mach 3 cranked delta designed in the late 50s. It was very ambitious, very expensive, and cancelled. Lockheed's YF-12 was intended to replace the F-108 using the same Hughes AN/ASG-18 radar/fire control system and GAR-9 (later AIM-47) missile as F-108 but at much less cost. But it too was cancelled. The F-106 was also optimized for the top right hand of the envelope but was fairly quickly replaced by the F-4 Phantom, a much less optimized and more rounded design and arguably the precursor of all multirole fighters. With these experiences and that of the Lightning, it seemed clear that the concept of a fighter optimized for high speed/high altitude intercept had been debunked, so I'm not sure why France decided to go that route with the Mirage 2000.
But none of the above efforts were a complete waste. A downgraded simplified version of the F-108 eventually became the A-5 Vigilante, the YF-12 became the SR-71, the Hughes AN/ASG-18 fire control system became the AWG-9 used in the Tomcat, and the GAR-9/AIM-47 missile became the AIM-54 Phoenix.
Speaking of the F-4, what was the strongest argument against it? It's dogfight performance. The fighter mafia folks insisted that ancient Mig-19 aircraft routinely beat the F-4 in a dogfight.. This was mostly true due to fighter operations doctrine and fighter pilot training, not aircraft performance. And even when proper training (i.e. Topgun) and adding leading edge slats enabled the Phantom to perform very well in a dogfight, the die was cast. Whatever replaced the F-4 would need to have a gun and eye watering dogfight performance, and that requirement remains to this day, even if it no longer makes sense. Witness the caterwalling when the F-35 was revealed to have less turn performance than the F-16. Interestingly, the performance specs for the future fighter appear to be remarkably similar to the specs the F-108 was designed for. Have we come full circle?