In 1966, Israel got its hands on a MiG-21, with major benefits for itself and the US Air Force. http://www.airforcemag.com/MagazineArch ... ughnut.pdf
On Aug. 16, 1966, Iraqi Air Force Capt. Munir Radfa defected to Israel in a MiG-21 jet fighter. The MiG-21 was, at the time, a state-of-the-art Soviet aircraft and the pride of Russia’s aircraft industry. The defection, orchestrated by the Israeli government, soon gave both Israel and the United States access to intelligence from a front-line Soviet fighter that the two nations would face in battle in the coming years.
While its armament was adequate for an interceptor, US analysts found the Fishbed’s gunsight deficient.“The tracking index drifts off the bottom of the windscreen when track-ing targets in excess of three Gs,” reads a declassified report from the Defense Intelligence Agency. Typical of delta-wing aircraft, the airspeed bleed-off during high-G turns was excessive. This speed-bleed decreased the MiG’s turn radius, however, and the G force could be sustained at slower speeds than comparable US fighters.Obviously, in a turning fight, this gave the Fishbed a tactical advantage.The DIA assessment identified several major aerodynamic limitations in the MiG-21. These included:
Exceptionally heavy pitch force required above 685 mph.
Severe buffeting below 15,000 feet when approaching 685 mph or a .98 indicated Mach number.
Exceptionally slow engine accelera-tion from idle to full military power.Poor directional stability in tur-bulence.
It is noteworthy that by the time the US became heavily engaged in the Vietnam War, the Soviet spon-sors and North Vietnamese Air Force commanders very effectively planned around the Fishbed’s limitations. They never committed their fighters unless there was a good chance of success and subsequent escape. In fact, in 80 percent of the North Vietnamese Air Force kills, the victims were unaware they were under attack.As USAF’s “Red Baron” study of aerial warfare in Vietnam determined, before the US obtained effective radar coverage of North Vietnam, the winner of an air engagement usually initiated the combat from a position of nearly unbeatable advantage.
Typically, DIA found, the Fishbeds were “vectored into the rear hemi-sphere for a high-speed, single-pass attack,” generally from a cross-course intercept.For example, when US fighters were bombing targets north of Hanoi, such as the Paul Doumer Bridge, en-emy MiG-21s would be vectored by ground control intercept radar from Chinese airspace to a position behind the Phantoms.
As the F-4s pulled up from their target, the MiGs would launch Atoll missiles and zoom back to political sanctuary in China. Air forces called these attacks “blow-throughs.”
At high altitude the Fishbed’s small size made it very difficult to visu-ally acquire or keep in sight while maneuvering. In a frontal or trailing attack, its slight silhouette also made it difficult to acquire on radar.
Despite being heavier, both the F-105D and F-4 were found basically superior to the MiG-21. Maintaining a high airspeed and avoiding turning engagements was the key to US success, although the F-4 was also aerodynami-cally superior in a vertical contest.
The Have Doughnut tests showed the F-4 had the capability “to control an engagement below 15,000 feet by ex-ploiting the MiG-21 airspeed limitation and airspeed bleed-off characteristic at high G.” In a visual encounter, the recommendation was to get behind the MiG and operate “in the vertical” during air combat maneuvering.
This is what was tried by Abhinandana's victim, the F16 first dove down, and then shot up. No escaping the off-bore sight capability of the R73. In an AWACS controlled environment, if the radar beam from the Mig21 can be narrowed, or alternatively, if the AWACS can generate a Fire Control Solution for the missile on the Mig, this can still be a very competitive airplane.
I am also wondering, how many of the issues identified here in the original 1966 Mig21 have been fixed in the bis and then the Bison.