The airspeed of a jet can be controlled by the pilot in the following four ways:
► Throttle position
► Drag devices
► Nose position in relation to the horizon
► Aircraft G
Throttle position controls how much slow, cold air you turn into fast, hot gas. Drag devices refer primarily to speed brakes. Nose position in relation to the horizon also affects airspeed. For example, a nose-low position will increase your airspeed because of the effect of gravity. Finally, G force causes airspeed to bleed off. Remember the brief discussion earlier about exchanging energy for position. No modern fighter flying at medium altitude can stay at corner velocity while pulling max Gs for long. As you pull Gs, you will get slower. It is important, however, to start maneuvering close to corner velocity because the first turn you make is usually the most important in the fight.
Fighter pilots should think in terms of both turn rate and turn radius. A fighter with a superior turn rate can outmaneuver a fighter that has a poor turn rate but a tighter turn radius. Fighter pilots have a simple two-word saying: “Rate kills.” What this means is that the ability to move (or rate) your nose is the primary means of employing weapons (which is what offensive BFM is all about). A bandit may have a tight turn circle, but if you can rate your nose on him and shoot, the fight is over. The flaming wreckage will no longer cause you BFM problems.
Vertical Turns
I have heard it said (incorrectly) that you fly in relation to the bandit and not the earth. While it is obvious that you must fly in relation to the bandit, you must simultaneously keep your nose in control of the horizon. Gravity affects airspeed, as already mentioned. Gravity also affects G availability. If you pull the nose of a fighter straight across the horizon, gravity will have no effect on your turn performance. When you pull the nose up or down, however, gravity becomes a player.
Figure 2-4 introduces a new term: radial G. To understand how an aircraft turns, you must understand that there are two factors that determine the rate and radius of a fighter’s turn. The first is the G being felt and read out on the G meter in the cockpit. The second is the pull of gravity. Radial G is a term used by fighter pilots to describe the effective G that determines a fighter’s turn. Figure 2-4 shows this concept by depicting a fighter doing a loop. In Figure 2-4, the cockpit G (the G felt by the pilot) is a constant 5 Gs. You will notice that when an aircraft is straight and level and trying to pull in the vertical, the effective G or radial G is only 4. Gravity is subtracted from cockpit G so that the jet is pulling only 4 radial Gs. When the fighter is pulling 5 Gs in the cockpit in the pure vertical (90° point) either straight up or straight down, gravity has no effect, so radial G is equal to cockpit G. When the fighter is inverted and pulling straight down at 5 Gs, gravity adds 1 G to your effective or radial G. The fighter, in effect, is turning at 6 Gs at this point. Radial G then is simply a term that describes the effective or turning G created by combining the positive or negative influence of gravity with cockpit G.
What Figure 2-4 shows is that cockpit G is not equal to radial or turning G when maneuvering in the vertical. Remember that 2° per second is a significant turning advantage. The extra G you can get by placing your nose below the horizon when you turn can give you at least 2° per second turn advantage. Most of the time, 1 GR equates to 3°-4° per second.
The concept of radial G can be seen in Figure 2-5. In this figure, both fighters are pulling the same cockpit G. Notice that the fighter with his lift vector below the horizon is turning tighter. What is not so obvious in this figure is that the fighter turning toward the ground is also moving or rating the nose faster.
Turning Room
When a bandit turns his jet, he creates BFM problems for you. To solve these problems, you need to turn your jet. In order to turn your jet and solve these BFM problems, you need turning room. Turning room is the offset or distance from the bandit. There are three basic types of turning room: lateral (or horizontal) turning room, vertical turning room, and a combination of both. In order to understand the concept of turning room, you must first understand turn circles. Turn circles are simply the paths that a fighter cuts through the sky when it turns. Figure 2-6 shows a turn circle.
The concept of turn circles is critically important to understand because, in order to turn and solve BFM problems created by the bandit, you must first drive your jet inside the bandit’s turn circle.
Here’s how turn circles and turning room are related.
A bandit turns his jet to defend against your attack. You need to get displacement from the bandit in the horizontal or vertical in order to turn and stay behind him. If you try to get displacement while you are still outside the bandit’s turn circle, it will not work. Why? Because if you are outside the bandit’s turn circle, the bandit can get around the turn and meet you close to head-on. This means that the bandit can turn and take away your turning room. Figure 2-7 shows a fighter turning for lateral offset outside a defender’s turn circle.
The bandit just keeps pulling, leaving the defender with no turning room. This same principle also works in the vertical. Figure 2-8 shows a fighter climbing, doing an old maneuver called a “high yo-yo.”
It is very dangerous to try to get turning room in the vertical, outside the bandit’s turn circle. If you are climbing in the vertical outside or close to the bandit’s turn circle, the bandit can get his nose around on you. When you pass at high aspect, the bandit will be nose high while you will be nose low. The bandit gets the first use of gravity to increase his radial G as you pass and will probably get behind you. For this reason, do not try to get turning room outside the bandit’s turn circle.
Any maneuvering you do outside the bandit’s turn circle will delay you from getting inside the bandit’s turn circle. You must be inside the bandit’s turn circle in order to turn and solve the BFM problem. In the next section, we will describe how to determine if you are inside or outside the turn circle of the bandit and how to use BFM to get and stay in weapons parameters.
Solving the Offensive BFM Problem
The reason you are out there burning jet fuel is simple: to get into weapons parameters and shoot. BFM is real simple against a guy hanging in a chute. All you have to do is watch out for him shooting at you with his pistol as you fly by and wave. Anytime you can take a shot and end the fight, do it. The problem is that when you start from 1.0 to 1.5 nm[18] behind the bandit and he turns, you will only be in AIM-9M parameters for a very short time. The AIM-9M is just like every other heat missile out there today — it doesn’t like the high line-of-sight rates generated by targets in tight, turning fights. You have time for one shot. If you miss, you had better be ready to put some offensive BFM on him, or you will end up wearing an AA-11 Archer. The end result of your best offensive BFM will be a gun shot. Here is how you do it.