We wrote about Constant Peg a while back, and mentioned Have Donut/Have Drill in that post.
Both programs were pretty much classified up the wazoo, but knowing about the capabilities of enemy airplanes is only really useful if it gets down to the warfighter’s level. Accordingly, classified training films of the evaluations were made and shown to select crews.
Oddly, the MiG-21 was flown under the cover name of “YF-110” which was the Air Force designation for the F-4 Phantom before the 1962 tri-service designation revamp. The Phantom, of course, would be the MiG-21’s primary opponent in the skies above North Vietnam.
You may also recall I posted a video a couple weeks ago about the operational evaluation of the Phantom in the hands of Tactical Air Command. One thing that very plainly struck me was that the entire film focused on the air-to-ground capabilities of the Phantom. TAC saw itself almost entirely devoted to air-to-ground missions. In spite of all their fighter pilot swagger, TAC left the business of serious thought regarding air-to-air combat to the Air Defense Command folks. But ADC faced an very different challenge than the TAC folks. It’s one thing to intercept a TU-95 Bear hundreds of miles away. Swirling around with nimble MiGs over their own territory while you’re trying to bomb the suburbs of Hanoi is an entirely different kettle of fish. And given the emphasis on using the missile armament of Sparrows and Sidewinders, neither of which liked to be fired from a wildly maneuvering jet, the air-to-air skills of the TAC had atrophied to a disastrous state. Where the US shot down about 10 MiGs in Korea for every Sabre they lost, the USAF in the early years of Vietnam saw Phantoms with only a 2-1 kill ratio, and at times, losses among all jets were as bad as 1 to 1.
Restrictive Rules of Engagement also squandered much of the Phantom’s advantages over Vietnamese MiGs.* The best way to shoot down a MiG is to bomb it on the ground. But fears of killing Russian advisors in bombing raids kept North Vietnamese MiG airfields off the target list for long stretches of time, and even when strikes were permitted, they were only allowed in fits and starts, not sufficient to keep the fields closed for more than brief periods.
The dismal performance of the Phantom in the air-to-air regime led the Navy and the Air Force to do a lot of soul searching. AIMVAL/ACEVAL, The Ault Report, Navy Fighter Weapons School (TOPGUN) and later Red Flag were all results the the services tackling head on their earlier failures. Technical improvements to both the Sparrow and Sidewinder greatly improved their performance. More importantly, tough realistic training greatly improved the aircrews ability to fight MiGs and win.
The MiG-21 was designed as a point defense interceptor, optimized for shooting down bomb-laden strike aircraft. It was fast as a thief. It could also turn on a dime… for a little while**. While its delta-wing planform gave it great initial turning capability, it also had enormous induced drag, causing it to bleed airspeed in a turn like a hemophiliac. And in air combat, speed is life. The Phantom wasn’t nearly as nimble a turning jet. What it did have, however, was two great big thundering J79 engines that gave it a very good ability to sustain its energy levels through a fight. A ham fisted pilot would find himself out of airspeed, altitude and ideas very quickly, but a well trained stick-shaker could manage his energy level to outfly almost any opponent.
The whole point of maneuvering in air combat was to place your jet in optimum firing position, which in those days was very roughly a cone of about 30 degrees from the enemy fighter’s tail, and a range of about half a mile to 1-1/2 miles. Woe betide the Phantom pilot who tried to yank the stick hard enough to turn with the MiG. He’d find that very likely, the MiG would turn the tables, and find the gomer riding in his “saddle.” Instead, US pilots were taught to abandon this “angles” fight, and instead fight an “energy” fight. If you can’t out turn an MiG, how do you do this? By exploiting the vertical. Humans are essentially two-dimensional thinkers. Most pilots, wanting to turn, instinctively turn in a level turn, parallel to the surface of the earth. As noted, this bleeds airspeed in a MiG. But a well trained Phantom pilot would make turns “out of plane1” A Phantom pilot that wants to execute a tight turn without bleeding a lot of energy would pull into the vertical. This would bleed airspeed, sure. But it would also quickly gain altitude. At the apex of the zoom climb, the Phantom at low speed could quickly tip its nose back earthward, execute a roll (with the practical effect of very rapidly changing its compass heading) and begin pulling out of the dive. And all that altitude is quickly converted back into a high airspeed, leaving the Phantom with reserves of energy to either kill the MiG, escape combat, or make further maneuvers.
Various other maneuvers, such as the “barrel roll attack” or the “lag displacement roll2” capitalized on the Phantom’s strengths, and minimized its weaknesses. The “high yo-yo” allowed Phantoms to exploit energy for angles, and the “low yo-yo” allowed Phantoms to generate energy or range/angle offsets as appropriate.
With improvement in weapons, and the vastly improved training of aircrews, by the time of Linebacker I in 1972, the US Air Force and US Navy increased their kill ratio to an impressive 12-1. Through the lean years of the 1970s, and on through the early 1990s, both services placed great emphasis on supporting the training in air combat needed to ensure success. Today, while there is still strong support, the emphasis has shifted somewhat to integrating air combat into the strike warfare arena, and using new weapons and sensors to make traditional dogfighting less likely. Many traditionalists decry this, but the fact is, since Desert Storm, most US air-to-air kills have been Beyond Visual Range engagements with little or no dogfighting involved.
*On the other hand, there were some very good reasons for some of the ROE restrictions. The big restriction was that pilots had to make a positive visual identification of their potential targets. That took away the range advantage of the Sparrow missile. But given the large numbers of US aircraft operating over North Vietnam, and the relative paucity of MiGs, without that restriction, the was a very great possibility of fratricide. There’s a good chance this rule saved more jets than it lost.
** The preferred MiG-21 tactic was to attack flights of F-105 bombers by coming up from behind and slightly below. Quickly accelerating to supersonic speeds, the MiG would dash in, fire off its Atoll heatseeking missiles, and dive away for safety. The Atoll was a virtual clone of the early Sidewinder missile.
1. The “plane” here isn’t the Phantom or the MiG, but rather the geometric concept of a plane, this one being the surface of the earth, which, yes, we know the surface is rounded, but for the purposes of aerial combat can be considered as a flat plane.
2. The Lag Displacement Roll lets a Phantom that is overshooting the MiG go outside the turn of the MiG, denying the MiG the opportunity to reverse its turn and attack. Instead of instinctively turning in the direction of the MiG, the Phantom barrel rolls away from the MiG and outside the track of the MiG’s turn. Once outside the MiG’s turn, the Phantom continues an in-plane turn with the MiG. It’s turn radius is larger than that of the MiG, but it’s turn rate matches well enough. Essentially, the turn comes to resemble two well matched runners on a track, with one on the inside lane, and one on the outside lane. So while the Phantom may not have a shot, he’s not at risk of becoming defensive either. Eventually, the MiG will bleed away so much energy that it can’t sustain the turn, allowing the Phantom to gain an angular advantage as well, and set up a shot.