The bandit turns. The first question you must ask yourself is “Am I inside or outside the bandit’s turn circle?”
How do you know? Watch the bandit’s turn.
If the bandit’s present turn rate will force his nose on you or even close to you, you are outside the bandit’s turn circle. For modern fighters at high G, you are normally outside the bandit’s turn circle at ranges outside 2 nm. At 1 nm, you are normally inside the bandit’s turn circle, and between these ranges, you are in a transition zone. These ranges, of course, do not really matter to a fighter pilot. When you start behind a bandit, you simply fight what you see. As the bandit turns, you predict where he is going and maneuver based on this prediction. For example, if the bandit is only pulling 4 Gs, then at 2 nm you are still inside his turn circle. Figure 2-9 shows the difference between starting at 2 nm from a 4 G target and starting at 2 nm from a 7 G target.
Most fighter pilots will not pull only 4 Gs, however, when they are in danger of dying. Still, you fight what you see.
If you are outside the bandit’s turn circle at the beginning of the fight, you are not in an offensive fight — you are in a head-on BFM fight. Head-on BFM is the subject of Chapter 4, but for now, just think about an AIM-9M shot in this situation. The bandit cannot shoot you until he gets his nose around to within about 40° of your jet. You should be able to get one good missile shot at him before he forces you inside Rmin.
Gun Shot Procedures
Flying good offensive BFM against a bandit will put him right in your gun sights. You’ll get him there by understanding the dynamics of getting into position, closing and firing.
Flying into Gun Parameters
It is time to discuss how and when we turn to stay behind the bandit. You are inside 1.5 nm on a hard turning bandit, and you need turning room to get around on his six. The first step is to observe the bandit’s turn. If you are outside the bandit’s turn circle, get ready for a head-on BFM fight. If you are near or inside the bandit’s turn circle, you have a positional advantage that you can keep. Shoot, if a shot presents itself, but don’t get mesmerized watching your own missile and forget to BFM. Next, drive to where the bandit started his turn. If the bandit drops flares or chaff, he will mark the point in the sky where he started his turn. Drive to this position (called the entry window). Figure 2-10 shows the entry window. The entry window is located inside the bandit’s turn circle. You can start your high G turn into the bandit once you arrive inside this window.
In Figure 2-10, the F-16 drove in a lag pursuit course to a position inside the bandit’s turn circle. By driving to this position, the F-16 gained horizontal turning room that the bandit can’t use or take away. You know you are at the entry window and must start your turn when the bandit is approximately 30° off your nose.
When you get into this relationship with the bandit, start your turn. Remember corner velocity. If you arrive at the window too fast or too slow, you will get stuck in lag pursuit because you will not have sufficient turn rate to get your nose out in front of the bandit.
The next step is to pull 7 to 8 Gs into the bandit. As you come around the corner, keep your nose in lag. If you see the nose of your jet approaching pure pursuit, ease up on the G. Hold this lag pursuit course until you get within 3,000 feet of the bandit. At this range, go to lead pursuit and get ready for a gun shot.
When you arrive inside 3,000 feet on the bandit with your nose in pure or lead pursuit, your throttle controls your overtake. Note this. In close to the bandit, with your angle-off less than 45° and your nose in pure or lead pursuit, the position of your throttle controls your closure. When you get saddled up for a gun shot, you must match airspeed with the target. In most cases, this will require constant movement of the throttle. In addition to banging the throttle off both stops, you may have to maneuver out of plane to control your airspeed. If a throttle reduction and the speed brakes don’t slow you down enough, roll the jet to orient your lift vector out of the bandit’s plane-of-motion and pull. Hold this lag pursuit pull for about two seconds; then ease off the G and watch the bandit. When he starts to move forward on your canopy, it is time to pull back into him. Pull your lift vector out in front of the bandit as you pull down.
Taking a Gun Shot
You are inside 3,000 feet on the bandit with your nose in lead. How do you take a gun shot? The gun in most fighters is actually a cannon. The F-16, for example, has an M61 20mm cannon which is common to almost every U.S. fighter. The M61 shoots high explosive incendiary (HEI) rounds at the rate of 100 per second. At the proper range, the gun is like a giant buzz saw. In order to carve up the enemy, however, you must understand the fundamentals of taking a gun shot. To hit a target with the gun, you must meet the following conditions:
► You must be in range. This range varies, depending on aspect, but it is usually about 2,500 feet at low aspect angles and about 4,000 feet at high aspect.
► You must have your nose in lead pursuit. The bullets fired by the gun are unguided projectiles that take time to get to the target. For most gun shots, the bullet time-of-flight (TOF) is .5 to 1.5 seconds. If you point directly at the target and fire, the bullets will pass behind the target. If the bullet moved at the speed of light, you could point right at a turning target and score a hit. Since the bullet is considerably slower, you must pull lead. This lead may not be very pronounced, however, at close range.
► You must be in the bandit’s plane of motion. When an aircraft turns, it carves a circle in the sky that creates a plane. In order for you to hit the target with the gun, you must be turning in the same plane as your target. For example, if the target is flying a loop and creating a vertically oriented plane of motion, you have to be flying a loop in the same plane as the target.
Using the Gun Sight
The new gun sight for the F-16 and F-15 is called EEGS.[19] EEGS (pronounced as it is spelled) stands for Enhanced Envelope Gun Sight. The EEGS funnel allows the pilot to match the wingspan of the target with the width of the funnel to determine the proper firing range. The other important gun aiming cue in the HUD is the gun cross. The gun cross represents the departure line of the bullets. You can consider the gun cross as the gun barrel. Bullets pass straight out the gun cross.
Figure 2-11 shows an F-16 HUD with the EEGS funnel and the gun cross.
So, how do you use the funnel? The gun in the F-16 is boresighted to 6 mils. This means that the gun is adjusted to fire a burst that will put 80% of the rounds inside a 6-foot diameter circle at 1,000 feet. This is a tight pattern. You can have either a highly concentrated burst that completely misses the target or a very lethal burst that vaporizes the target. It just depends on the quality of your gun sight (and your ability to aim it.) Air-to-air situations are always dynamic, and targets under attack will normally jink violently to stay alive. Since the sight (and your reactions) are not instantaneous, it is likely you may achieve a highly accurate miss; that is, a tight burst that finds only empty air. The sight was lined up and stable, but you missed. How could this happen? The sight was lying because the target was jinking faster than the sight could react. The way to overcome this problem is to strive for an inaccurate hit. You do this by using the EEGS funnel to fire a burst while moving the target through the area of uncertainty. The EEGS funnel gives you a perfect solution when the wingtips of the target match the width of the funnel. If the target is jinking, however, this “perfect solution” may be in error.
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