I’ve mentioned previously that I participated in an aggressor program up in Alaska, pitting our Lockheed T-33s against the Alaskan Air Command F-4Es. The goal was to break bad habits that fighter pilots can inadvertently pick up if they always train by dogfighting with identical aircraft.

As part of this Dissimilar Air Combat Tactics (DACT) training program, several of us T-Bird pilots were qualified for the DACT missions and, eventually, developed a training program to qualify other T-Bird pilots for DACT.

However, before engaging with the Double Ugly (aka F-4), we had to learn the basics of dogfighting each other (T-33 vs. T-33). Basic fighter maneuvers (BFM) is the generic term for the set of maneuvers that are employed during within visual range (WVT) combat to allow an attacker to maneuver into lethal parameters against a bandit. Defensive BFM allows the defender to save his know-know-what and, he hopes, become the attacker.

One of the first BFM tactics learned is the Yo-Yo, wherein an attacker reduces both the distance and the angles between his aircraft and the bandit’s aircraft so he can spit some lead at him or launch a heat-seeking missile. There are two basic variations: High Yo-Yo and Low Yo-Yo. The choice depends on the relative airspeed and distance between the two aircraft and the dynamics of the fight. During initial BFM training, the defender maintains a constant airspeed in level flight with a constant G load.

Here’s the standard Low Yo-Yo diagram (the shaded aircraft is the attacker and the numbers are time references):

At the start, both aircraft are at positions labeled 1. This puts the attacker too far back and in a lag pursuit position (i.e., his nose is pointing behind the defender’s aircraft). The attacker must tighten his turn (pull more Gs) and descend to gain airspeed. This allows the attacker to cut across the defender’s circle for an intercept. However, this maneuver results in a high angle-off position for the attacker, in addition to being well out of the defender’s maneuvering plane. Therefore, the attacker must choose the correct moment to convert that excess airspeed into a higher altitude (back in the defender’s maneuvering plane) by starting a pull-up. If he does nothing else, he would arrive in the defender’s plane with an even higher angle-off, resulting in an overshoot (vertically and/or horizontally). To solve that problem, the attacker must time a slight vertical overshoot so that he can roll back down on the defender, letting God’s G help him. He then times his pull-down to arrive back in the defender’s plane with a turn matching that of the defender (actually a bit tighter to give him a lead pursuit solution from which to fire).

There is another standard variation of the Yo-Yo: the High Yo-Yo:

This time, the attacker pulls up and rolls over into a tight descending turn, again allowing God’s G to help him pull to the inside of the defender’s maneuvering plane. With higher airspeed at position 4, he can pull a tighter turn to “saddle up” on the defender in a shooting solution (lead pursuit).

Of course, in the real world the defender is unlikely to play “duck” and hold such a nice, steady, and level turn, unless you’ve managed to sneak up on him. You may find it necessary to transition from a High Yo-Yo to a Low Yo-Yo, or vice versa…or employ one of the other maneuvers in the BFM bag of tricks. But everyone has to learn the basics one step at a time before allowing the fight to progress to a free-play environment.

When we fought the F-4E with a T-33, we often used the Low Yo-Yo and turned really hard to meet the F-4 on the opposite side of the fighting circle with as much airspeed as the old Lockheed Racer would give us (up to its maximum of 505 KIAS or 0.8 Mach or “aileron buzz,” whichever came first. Our big advantages were the fact that we could out-turn the F-4 at any speed in our envelope and could maneuver well at airspeeds below 200 KIAS. The Phantom’s biggest disadvantages were that it lost airspeed quickly in a hard turn and maneuvered like a bloated pig at anything much below 250 KIAS.

All of which meant that our goal was always to force them into a hard turn at the outset. How we did that falls into the realm of Dissimilar Air Combat Tactics 9DACT). But, trust me, we did it regularly.