3.0 CHAPTER 3
by Brooke
This chapter discusses more about aerodynamics and flight dynamics, more about gunnery, and basic ACM (air-combat maneuvering). ACM is also covered in the "More ACM" Appendix -- I suggest that you look through that appendix after reading this chapter and again after reading Chapter 7.
3.1 AERODYNAMICS AND FLIGHT DYNAMICS
Chapter 1 talked about induced drag. Induced drag is the part of drag that is a result of the lift generated by the wings -- the greater the lift generated, the greater the induced drag. Induced drag acts in a direction to slow down your plane. This is important to keep in mind and has many applications to ACM (air-combat maneuvering).
There are times when you'd like to slow down as quickly as possible (for example, if you want to make a high-speed enemy overshoot you). Obvious ways to do this include chopping the throttle, deploying a speed brake (if your plane has one), and deploying flaps. A less obvious way is to pull a lot of g's -- more g's means more lift which means more induced drag. Induced drag gets quite large when you pull 6 g's.
There are also times when you'd like to keep your speed or to gain more speed. In that case, keep in mind that you don't want to pull g's if you don't have to -- fewer g's means less drag. So, when you are running away from an enemy, don't be ham fisted -- don't pull more than about 3 g's unless it's necessary.
Another aspect of aerodynamics that is useful to keep in mind applies to flaps. The deployment of flaps results in increased drag and in a nose-down pitch moment. For low-wing planes (most of the planes in Air Warrior), drag on the wing (being below the level of thrust and below the center of gravity of the plane) adds to the pitch moment, and so when flaps are deployed, the plane will pitch nose-down, and you have to correct for it.
There are two situations where this is dangerous. First, if you are flying low to the ground, be careful when you deploy flaps. That nose-down pitch can be enough to nose you into the ground if you aren't paying attention. Second, be careful of deploying flaps at high speed in planes that weren't built for it. The P-51 and P-38 have high-speed flaps, for example, but the bombers and the C-47 definitely do not. You can get into severe trouble if the flaps are deployed and you subsequently get to high speed. The higher the speed, the greater the aerodynamic affects and the greater the pitch moment. In some planes, the pitch moment can be so great that you won't be able to keep the plane from nosing down even with full elevator. These planes won't let you deploy the flaps at high speed, but they will let you deploy the flaps at lower speeds and then get up to a high speed (by deploying the flaps at low speed and then diving, for example) where you will
have this problem. Be careful in bombers and C-47's -- retract flaps before diving.
(For those who know more about aerodynamic theory, it should be stated that Air Warrior does not model the drastically increased drag due to flow separation off the top of the wing as would occur during the buffeting effect. Therefore, while in real planes it is not always best to pull all the way into the buffet during turns because of the greatly increased drag, in Air Warrior there is no increase beyond what one would get from induced drag. I hope that they add this extra bit of realism in future versions.)
Obviously, changing direction is an important part of aerial combat, and every change of direction involves a turn of some sort. (A loop is just a turn in a vertical plane.) There are two measures of a turn that are important in combat: turn radius and turn rate. A small turn radius makes it harder for an enemy to bring his guns to bear on you, and he will need more lead. A large turn rate is good as that means you can change directions more quickly, coming around on an enemy's tail or getting the hell out of the way. As a general rule for the planes represented in Air Warrior, the radius of a plane's turn is smaller the slower it is flying, all the way down to near stall speeds. (The same holds true for cars: you can turn more tightly while driving slowly than you can while driving at 60 mph.) The rate of a plane's turn increases with decreasing airspeed until you reach a speed at which you can no longer pull 6 g's (200-250 knots or so for most of the WWII planes). Then the turn rate decreases. So, turn rate and turn radius are better the slower you go, down to about 200-250 knots (depending on the airplane) -- slower than that, you trade off a worse turn rate for a better turn radius. Managing turn rate and turn radius is thus a matter of managing speed.
Speed management is a part of energy management. Energy for an aircraft is the sum of its kinetic energy (due to speed) and its potential energy (due to altitude). You can trade speed for altitude by climbing, and you can trade altitude for speed by diving, both without losing total energy assuming that you don't pull a lot of g's. Energy is used up by drag and replenished by the thrust of your engine. Induced drag (discussed in Chapter 1) increases with pulling g's, and thus so does energy loss. Overall then, you can trade energy freely between speed and altitude (not wasting it in the trade); you can spend energy by pulling g's (turning); and you can gain energy back by letting the thrust of your engine add it back gradually over time.
Let's say that you are flying rapidly along and want to do a 180 degree turn quickly. What's a good method? You could just crank your plane into a hard, flat turn. In that case, you would have used up a lot of energy by pulling a lot of g's, and you would have had a poor turn radius and turn rate because at least the start of your turn was entered at high speed. Instead, you could zoom climb, converting speed into altitude. Now your speed is lower, and you can turn rapidly and tightly. Then, once you have turned, you can dive back down to your original altitude, and you will have more speed than you did at the end of the flat turn. This is an example of wise energy management and is the key to one style of fighting -- energy fighting -- which we will discuss later in the chapter.
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3.2 GUNNERY
Chapter 1 also talked about gunnery and leading the target. Air-Warrior planes have lead-computing gunsights -- they give you an idea of how much lead you need (i.e., how much in front of the target you need to aim) if you have the range set right and assuming that you and the enemy continue to turn at the same rate. You put the lead-computing sight on the target and try to hold it on the target -- that shows you the right amount of lead to be pulling at the moment.
Many pilots prefer to aim by looking at the tracers alone and not by using the lead-computing sight. If you do use the lead-computing sight, the best range to set it for, in my opinion, is 400 yards. At ranges longer than that, you shouldn't really be shooting (unless the target is not maneuvering much); and at ranges shorter than that, you can aim easily enough without the help of the lead-computing sight. The maximum effective range on most guns in Air Warrior is about 600 yards -- beyond that, you're usually wasting your ammunition.
I pay attention to the lead-computing sight only at 300-500 yards in order to see how much lead I should pull. At ranges shorter than that, I pay more attention to the tracers and mostly ignore the sight. It's just a matter of preference -- you'll develop your own style with experience.
In Air Warrior, the tracers travel the same path as the non-tracer ammunition (unlike in real life where there is sometimes a significant difference) -- so your bullets are definitely going where you see the tracers go. Yet sometimes in Air Warrior, it looks like you should have hit an enemy and yet you will see no damage to his plane. This situation is called "blanks" by players and is due to to network effects, such as packet delays. Sometimes the enemy plane will jump around erratically (called "warping"), making it hard for you to line up a shot. These are also due to packet delays. In my experience, for most people, these problems are infrequent and not severe -- but tell the network people if the problems become frequent or severe so that
the problems can be fixed.
Also sometimes you might find yourself taking hits when it looks like an enemy plane is too far behind you to hit you. The planes you see are typically delayed about one second from where they really are due to the transmission times inherent in the network. If a plane is traveling at 300 knots, it travels about 175 yards in a second. So, if you and your pursuer are going 300 knots, the actual distance to the pursuer is about 175 yards less than what you see on your readout. If the delay is 2 seconds, it's 350 yards less, and so on. Generally, you aren't safe from taking hits until the enemy is more than about 1500-1600 yards back -- that is good enough to account even for pretty severe transient delays in the system.
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3.3 BASIC ACM OVERVIEW
Chapter 1 talked a about some of the basic aerobatic maneuvers such as loops, Immelmans, split S's, and rolls. Add these to climbs, dives, and regular turns and to high and low yo yo's (which I'll discuss soon), and you have a basic set of air-combat maneuvers that you'll string together as appropriate -- an air-combat vocabulary.
A high yo yo is like a normal turn except that it isn't a flat turn. Consider your flight path during a flat turn as the outside rim of a paper plate: a regular circle. If you take a portion of the paper plate and fold it so that one part sticks up into the air at an angle, you have the type of flight path you'd take during a high yo yo. For a high yo yo, you go into the turn as usual, then pull back more on the stick so that the plane goes into a climb, then roll into the turn much more steeply (perhaps going to a vertical bank or even going slightly inverted) while continuing to pull back on the stick so that you dive back down, then rolling back to a more shallow bank to pull out of the dive to go back into a normal flat turn. It's a normal turn with, in the middle of it, a climb up and then a dive back down.
A low yo yo is similar except it's like folding the paper plate so that one part sticks down at an angle -- it's a turn with a dip in the middle of it. You go into a turn, let the plane dive a bit, and then pull back up to the altitude at which you started, all while turning.
Now, what use are these maneuvers, anyway? Once you master the maneuvers, how do you string them together in order to kill your aerial opponents? This is the meat of ACM, and we'll cover a bit of it here and then a lot more in Chapter 7. Your choices for maneuvers depend upon the style of fighting you use (which depends upon how many friends and enemies are around, what types of planes are around, what type of plane you are in, the energy states of the planes, the fighting style of your opponents and allies, and your preferences in fighting -- no small list of variables, which is why humans are still better than computers at ACM). Let's talk about styles -- there are three basic styles: angles fighting, energy fighting, and boom-and-zoom (B&Z) fighting. (Sort of like in kung fu movies: "Ah, I see that you use angles style. I studied energy style under master Ling Cho. Prepare to die.")
Angles fighting is the most common in Air Warrior. Here, you spend your energy (early in the fight) on getting a good shot at your enemy, hoping to shoot him down early, before all of your energy is used up. It's the most common style in Air Warrior as it results in the quickest action and requires little patience. Most angles fights involve a quick high-G lead turn in some plane (it might be a lead Immelman or a lead high yo yo or whatever). A lead turn is a turn done so that you get within firing range of an enemy and have enough lead so that you can get the shot -- like cutting him off at the pass. You are going for the best angle, whatever that happens to be at the time. An angles fight, if no one is shot down early, often degenerates into a low-altitude stall fight, where both planes are chugging around at stall speed and 200 ft. altitude. At that stage, low-speed turning rate (and the pilot's ability to turn on the edge of a stall -- see Chapter 2) is very important.
Energy fighting takes more patience and forethought. It involves being very careful on how you spend your energy, trying to trick your enemy into wasting more energy than you do. You pull g's only when you have to do so or when it results in little loss to your energy (such as by pulling few g's or pulling g's only when you are slow). If you are successful in holding onto more energy than does your enemy, when you are at a clear energy advantage, you spend your energy on getting into a good position (usually onto the enemy's tail). Energy fighting is safer than angles fighting because (until you spend your energy near the end on saddling up, and you generally don't do that until you are fairly sure that it will work) you have a decent amount of energy to spend in an evasive maneuver or in running away. Energy fights have angles fights as the end game -- you can always start an angles fight if the energy fight isn't going well.
B&Z fighting takes the most patience and forethought, is the safest form of fighting, and results in the lowest rate of killing. In B&Z fighting, you find an enemy at a lower altitude (or really a lower energy state); you close on him at high speed (usually trying to set it up so that you are closing on his tail or at least the rear quarter) -- this is the "bounce"; you take a shot; and you "zoom" off to safety. Repeat as necessary. If it looks like someone can get into a B&Z position on you, you run away (unless you want to convert to a different style of fighting).
I like angles fighting when I'm just horsing around, looking for quick action, or when I'm fighting an opponent who isn't too skilled. I like energy fighting when I'm looking for quick action but am fighting a skilled opponent. I like B&Z fighting when I'm flying planes that don't turn well at low speed compared to the opposition or when I want to see how many kills I can get before dying.
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3.4 BASIC ACM SPECIFICS
OK, so I've blabbed on about generalities. Now, how about some specifics? Let's start by discussing some basic situations and then move on to a few more involved ones.
In WWII, a lot of air-to-air kills came from situations where the enemy was flying straight and where the victorious pilot flew up behind him without him noticing and shot him down, usually by diving from a higher altitude (classic B&Z). In Air Warrior, because there is radar and very good visibility, it's much harder to sneak up on someone without him noticing, but it does happen -- especially in target-rich environments where a person can get fixated on a target or two and forget to watch his tail. So, rule #1 is "watch your tail." Obviously, you can't watch your tail at all times, but it's easy to look back in Air Warrior -- make sure that you do it as often as the situation demands. If you are fighting one enemy and if there's no one else around, you don't have to check your tail much. If you are fighting in a huge dogfight involving many enemy planes (a "furball"), you have to check your tail a lot -- every few seconds or so to make sure that no one is saddling up on you. Remember to look back when you stop turning hard, perhaps in order to get a shot. Look back before or as you slack off on the turn.
Actually, just watching your tail isn't good enough. Before you get into a fight (i.e., get engaged), you should be looking around a lot, including checking your blind spots, such as underneath your plane. Look all around, and occasionally do a roll or a steep bank to the left and then to the right so that you can look for enemies coming from underneath you. Then, once you get into a fight, you need to watch your opponent as much as possible. It is a common axiom in ACM that "if you lose sight of your opponent, you will soon be dead." That's why it's so important to learn to use the view keys so well that they are second nature. If you do lose sight of an enemy in a dogfight and don't know where he's gone, look first behind you then check
other views -- and do not stop turning or maneuvering. I have fought many, many inexperienced pilots who slack off on their turns or other maneuvers (sometimes they even fly straight) after losing sight of me in a fight. They generally live for only a handful of seconds after that.
So, assuming that you see the enemy coming, what do you do if he is diving on you? If you have lots of time to prepare, do a gentle turn toward the enemy. That way, you don't waste your energy in pulling high G's, and the enemy is now approaching you from the front, making the closure speed higher and the probability of hitting lower. Now you just have to avoid the head-on shot, a subject discussed in Chapter 7.
What if you don't have lots of time to prepare, and an enemy is closing on your tail for a shot? A hard turn or hard loop is the answer -- you have to get out of the way. (By hard, I'm talking about pulling 5-6 g's or as many as you can manage.) I have three favorites, depending on the situation.
First, if I don't think that the enemy has such a huge speed differential on me and if I have a decent amount of speed, I like a hard climbing turn or an Immelman that is slightly off to one side or the other rather than executed purely in the vertical plane. It's harder for an enemy to track you if you are turning in other than purely horizontal or vertical directions; and the climb converts speed into altitude so that I don't just waste all my energy in the turning part of the maneuver.
Second, if I don't have much speed so that I can't do a hard climbing turn without ending up at stall speed (and thus not being able to generate a good turn rate), I do a hard nose-low turn (usually very nose low in order to get quickly the speed needed to pull some decent g's). It's hard for an enemy to get a shot on you under these circumstances. It's especially effective at low altitudes, where the enemy can't concentrate as well on shooting you if he also has to worry about hitting the ground.
Third, if the enemy has a huge speed differential on me (i.e., such a huge energy differential that gaining just a little energy on him won't matter), I chop my throttle and do a hard split S. A plane that's going much faster than you are can't match your maneuver in these circumstances because of the turn-rate and turn-radius explanations give above. If he tries to follow (and doesn't chop throttle and apply speed brakes or high-speed flaps or both), he will end up at a much lower altitude than you. If not, if he almost manages to stay on you somehow (speed brakes, chopping throttle, whatever), you can do a second split S. The goal is for you to have him end up way underneath you. Then, despite his greater speed, you have an altitude advantage. Because he was probably pulling very high G's at high speed and because you might have been pulling only moderate G's, you might have been able to eat into his initial energy advantage this way -- you try to trick him into wasting huge amounts of energy. (It's an especially funny trick when you can do a split S and miss the ground but he can't because his speed is too high. Yuk, yuk, yuk.) Make sure you only do this if when the enemy has a lot of speed on you and is really hauling. Otherwise, a hard split S really wastes a lot of energy -- it's only good in the case where the enemy will waste a lot more than you do.
Let's say you are the one who has done the pass on the enemy, and because he is evading, you are going to overshoot. What should you do? If the enemy doesn't turn hard enough or if your speed is not that much greater than his, there are techniques you can use to keep from overshooting. If he does a flat turn, you can do a high yo yo. You trade some speed for altitude, turn with the enemy (now that your speed is lower), then spend the altitude part of your energy in holding a higher-G turn (and higher turn rate) than your enemy can perhaps muster. If he flies mostly straight and you still are overshooting, you can climb up, flip inverted, and then pull back down onto his tail (sort of like a high yo yo without turning). Or you can do a big barrel roll, eating up some speed by pulling g's. Or you can chop throttle, apply speed brakes (if you have them), or deploy flaps (if you have high-speed flaps), or any combination thereof. If your speed is very much greater than his, you can just pull up, get to altitude, and come back for another pass (B&Z fighting). Or, you can do several B&Z passes, getting the enemy to use energy in high-G evasive maneuvers while you convert to energy fighting.
By the way, how do you convert energy into a good angle assuming you have an energy advantage on your enemy? The key is in making the enemy get slow so that his turn rate is poor. Then you use your energy (usually in the form of altitude over the enemy) to generate enough speed so that you can out-turn the enemy. If you are turning over an enemy, and the enemy is chugging around in turns at 130 knots and 3 g's, you can go into a diving turn and pull 4-6 g's for a little while (until your initial energy advantage is used up by the extra induced drag). You spend that energy on extra turning rate when you think that you are close enough to the enemy's tail so that a burst of extra turning rate is all you need to get onto his tail for a shot.
Another way to temporarily boost turning rate at low speeds is to use war-emergency power (WEP), which lasts up to about 10 minutes in a lot of planes. It boosts turning rate because it boosts your speed. You can also deploy flaps. Some planes allow you to deploy 10-20 degrees of flaps that will increase turning rate. The disadvantage is that they will also drop your speed, so you won't be as able to split S and to run away or to follow an enemy who does a high yo yo. I don't use flaps much unless I'm in trouble in a stallfight, then I give them a try.
As for angles tactics, the simplest attempt is to point your lift vector at the enemy and pull as many g's as you can until you have enough lead for the shot ("point your lift vector at the enemy and pull" as it was explained to me by "Sheik," a former F-16 pilot, when I asked him how F-16 combat compared to prop-plane combat). The lift vector is the direction of lift from the wings. Imagine yourself sitting in an airplane in flight. Imagine an arrow drawn from your ass to the top of your head -- that's the lift vector, more or less. This strategy is the equivalent of the strategy a computer chess program uses when it looks zero steps ahead in order to figure out its move, but it's better than trying to predict ahead with an undeveloped set of prediction rules. It's the same as just trying (for as many g's as you can manage) to get your nose around onto the enemy for a shot. It doesn't really matter what the enemy is doing -- you follow him wherever he goes and are just trying to get enough lead on him for a shot. This isn't such a horrible thing -- it's simple; it's common among the newer pilots; and it's a natural tactic to use when you first start dogfighting.
Another common situation in Air Warrior is the head-to-head pass. Here, if I want to engage, I prefer energy tactics. After I pass the enemy (and avoid the head-on shot with a jink, as discussed in Chapter 7), I go into about a 40-45 degree climb, converting speed into altitude. When I'm at about 150 knots, I pull back over in an Immelman. If the enemy wasted energy, I now have an altitude advantage on him, and I can do passes on him from higher altitude until I get into a good position to use my energy in a high-G turn onto his tail (G's that he can't match if he is out of energy). The danger is in getting shot during the low-speed-Immelman part of the maneuver. If you see the enemy getting closer than, say, 1200-1300 yards or so during your climb, pull into a hard Immelman right away -- don't wait for 150 knots. Another danger is that the enemy goes into a dive before you merge, then pulls up hard, coming up under you for a belly shot. To defeat this, if the enemy dives as you approach head to head, dive at him -- deny him the belly shot.
Do you want to try for the belly shot? The previous paragraph is an energy-fighting approach. The belly shot is an angle-fighting approach. To do it, when you get to within about 2500-3000 yards of the enemy, go into a steep dive. As the enemy approaches to within about 1500-2000 yards, pull up into a lead climb toward his belly. You want to get the right amount of lead on him so that, as he flies past, you can fill his belly full of lead.
Some people do very steep high yo yo's at the merge (the "merge" is when the two planes pass each other in close proximity). This is an energy-fighting approach, too, and is probably about as good as an Immelman. It might be safer, but I still like the Immelman a bit better for energy reasons.
What if you are in a fight, it is going badly, and you want to get out of it? How do you disengage (or, in the vernacular, "bug out")? This is perhaps more tricky than winning the fight in the first place. Having a plane that is faster than your opponent's helps a lot, as does having a plane that can withstand some hits in the process. There are a couple of techniques that I like, both involving jinking. Jinking is flying erratically, unpredictably, in an effort to throw off the enemy's shot.
First, there is the spiral escape. It relies on the fact that it's hard to shoot someone when you're both close to blacking out. Here, you keep turning (so as not to present a good target) and go very nose low. Soon, as you accelerate, you can pull 6 g's even if you couldn't before. Erratically change the angle of your bank, but keep pulling lots of g's, and keep increasing your dive. Don't pull more than 6 g's, though, or you'll black out. You will rapidly accelerate, and it will be hard for the enemy to get a good shot on you as he is pulling 6 g's to stay on you and as you wiggle around.
Second, there is the vertical escape. It relies on getting as much speed as quickly as possible. Here, you roll inverted and pull quickly into a vertical dive (like executing half of a split S). As you dive vertically, barrel roll your plane (which works great all by itself as a defensive if you have a roll-rate advantage on the enemy -- see Chapter 4 and Chapter 7), apply 2-3 g's of positive and negative elevator at random, roll left and right at random, or any mixture of the above. Unless you have a good roll-rate advantage, the more erratically you fly, the better. Be careful not to apply more than 3 g's of negative elevator or you will red out,which is just as bad as blacking out. This maneuver works best if you can start the split-S portion when the enemy isn't right on your tail. The maneuver is best commenced by shouting "Screw this!" as you dive out of the fight.
There are more suggestions in Chapter 7, but this is plenty for now. There is a great deal more to ACM than can be taught in a book -- you will have to fight a lot in order to learn. The main point of reading all of this is to speed your progress, not to eliminate the need for in-flight experience.
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3.5 CHAPTER 3 EXERCISES
3.5.1 MAX-G VS. 3 G TURNS
Get your plane up to 275 knots or more and try some 180 degree turns at various g's. Does pulling max g's (i.e., the most you can pull without blacking out or stalling) instead of 3 g's really make that much of a difference in deceleration? How about for a 360 degree turn?
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3.5.2 ZERO G DIVES VS. VERTICAL DIVES
Climb to 7k and compare two techniques of diving away: the zero-g extension and the vertical dive. For the zero-g extension, push forward on the stick and maintain zero g's until you need to start a pull out. You might need to maintain just a little above zero g's in order to keep your oil pump happy -- some planes can't take zero g's for too long. Aim for pulling out so that you end up right on the deck. For the vertical dive, roll inverted and pull max g's until you are vertical. Again, hold the vertical dive as long as possible and aim forpulling out so that you end up right on the deck. When you are on the deck, which maneuver resulted in the highest speed? Which maneuver would give you the most separation from an enemy, and which would give you the quickest separation?
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3.5.3 MAX-G, LOW-G, AND EXTENDED-CLIMB IMMELMANS
Try various ways of doing Immelmans. Get up to 275 or more knots and try a max-g Immelman. Note the speed and altitude at the top.
Then try one starting at the same speed and altitude as before, but pull less g's. Note the speed and alt at the top, then do a zero-g extension back down to the alt at which you completed the max-g Immelman. How does your speed compare now with that at the completion of the max-g Immelman?
Finally, get up to the same starting speed and alt as before, and pull up gently into a steep zoom climb (45-60 degrees). Stay in the climb until the plane reaches about 150 knots, then pull over into an Immelman. Again, note the speed and altitude at the completion, then zero-g extend back down to the alt of the completion of the max-g Immelman and note the speed there.
Of these three maneuvers, which seems to use energy most efficiently? Which would you use in a one-on-one fight against an identical aircraft at the same speed and alt and if the fight starts with a head-on pass? What do you think of pulling max g's up into a vertical zoom climb, holding it until you nearly reach stall speed, then pulling back down into a vertical dive? Under what conditions would that be a good maneuver?
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3.5.4 ANGLES FIGHTS
If your Air-Warrior program supports off-line missions, take your favorite angles fighter up (Spitfire, Ki-84, Zero, whatever) and have a one-on-one fight. Use angles tactics only.
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3.5.5 B&Z FIGHTS
If your Air-Warrior program supports off-line missions, take your favorite B&Z fighter up and have a one-on-one fight. Use B&Z tactics only. Pick a plane that climbs well (Spitfire Mk IX, N1K1, Bf 109F-4, or F4U-1D) and, if you can, have the computer-controlled opponent in a plane that doesn't climb well (P-40E or P-47D).
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3.5.6 ENERGY FIGHTS
If your Air-Warrior program supports off-line missions, take your favorite fighter up and have a one-on-one fight. Use energy tactics only. If you can, have the enemy in the same type of plane that you are flying.
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