The MiG-21 was a very small, maneuverable aircraft that had a good record in combat against US pilots in
Vietnam. But it was no world beater.
When Vietnam begain the U.S. Air Force and U.S. Navy were operating equipment and tactics devised for the Cold War. US pilots were clearly regarded to have superior technology and training. The technology part was generally true. The MiG-21 was superior to most of the Century Series Fighters employed by the USAF early in the war, but the MiG-19 and subsonic MiG-17 were not. None were better than the F-4 Phantom, or the short legged Navy F-8 Crusader in air to air combat.
What the MiG-21 along with the other Russian fighters had going for them is that it was small. That meant that all things being equal, the MiG would sight its targets first, and once spotted US pilots often assumed that it was farther away than it was, which led to tactical mistakes. Also, unlikely as it seems the MiG-21 looks very much like the F-4 from many angles, which made mixups possible. As there were more Phantoms in the sky at any one time than the MiG-21, it was often left alone until very late in the game.
But the real issues were tactical. In 1965 it was assumed that the air to air missile would prove dominant, so cannon were left off the Phantom fighters under the assumption they would be unnecessary. That assumption proved false, and the cannon was returned in the later F-4E variant of the Phantom. Also US pilots practiced aerial combat maneuvering (ACM) against other Americans, who were often in the same aircraft. If two adversaries are in the same aircraft pure pilot skill and early aircraft recognition willl usually determine the winner. But different aircraft have different flight characteristics. One may have the advantage of speed and climb, versus turn rate, and these advantages may reverse at different speeds and altitudes. Pilots fight as they are trained. American style training did not teach them to do things that maximized their airplane's advantages, and even played into a MiG jockey's strengths.
The average North Vietnamese pilot enjoyed a few distinct advantages over his American opponents. First MiG pilots were instructed to engage in combat only when they enjoyed a favorable position. Most US aircraft, including the fighters, were being used as bombers. Dropping your bombs early to engage an enemy was regarded as failure by the Americans, and a victory for North Vietnam. US aircraft were there to attack ground targets, and did not break off from difficult fights.
Second, there were so few North Vietnamese fighters that for most US pilots, an actual dogfight was very rare, which meant their peacetime training against similar aircraft prevailed That meant that North Vietnamese pilots who survived their early flights had extensive experience fighting US fighters, and thus their tactics were refined to a high level. But US pilots were trained to fight other Americans, and that gave them some bad habits that had to be unlearned. They were often surprised by the performance of their adversaries. They often misjudged distance and aircraft type.
This was addressed by the Ault Report prepared by the Navy which led directly to the Top Gun program that re-introduced dissimilar aircraft ACM training to the fleet. Before the introduction of Top Gun, Navy fighters killed 1.1 Vietnamese aircraft for each US fighter lost due to all causes. After Top Gun pilots filled the fleet, the kill ratio jumped to 13-1, which is above the Korean War ration of 10-1. The US Air Force learned similar lessons, and formed its Aggressor Squadrons to teach dissimilar ACM at such exercises as Red Flag. The combat effectiveness of US units leaped once such training was initiated.
The MiG-21 is a small, maneuverable daylight fighter that can be a deadly adversary in skilled hands. Particularly when it gets to fight on its terms. But the speed and climb rate of the F-4 Phantom gave it a distinct advantage when using the vertical, and its superior avionics multiplied those advantages when clouds filled the sky. Noders should also remember that North Vietnam's top pilot, Colonel Tomb, flew the older, subsonic MiG-17.
It is always hoped that your fighter pilots will shoot down far more aircraft than they lose. But air to air combat is not the point of an air campaign. One can enjoy a favorable kill ratio and still lose the air war. Victory goes to he who goes where he wants, does what he wants and keeps his enemy from doing the same.
kermitov has contributed an anecdote he heard from an American pilot who served in Vietnam. Because the MiG-21 was considered the toughest adversary, they were highly sought after. North Vietnam used to use them as bait, and once engage throw some MiG-17's into the party. The 17's would cover the faster MiG-21's escape, and their dissimilar characteristics would present problems for pilots whose mind was focused on the '21.