Basic Energy Theory
by Murdr

To the beginner or novice, statements regarding E (energy) can at times seem abstract and mystical. However, these concepts are rooted in some basic fundamentals of physics and are prerequisite to tactical deployment of Air Combat Maneuvers (ACM). In fact, your choices of ACM are limited only by your airframe's abilities and your state of E.

There are two types of energy. Kinetic energy is the energy you have now - your speed. Potential energy is the energy you have "in the bank" - your altitude. By diving, you can cash in some of your altitude (potential energy) and convert it to speed (kinetic energy). "E" refers to the total kinetic, and potential energy you have available to you at any given moment.

The potential problem here should be obvious - just like money in your bank, once you withdraw and spend it all, you are broke. Use up all your alt and your potential energy bank account dries up. All you have left is the money in your pocket - your speed. Use that up too, and you are left low and slow with nowhere to go. Well, not exactly true - you can probably find a free ticket back to the tower without searching very hard.

The two energy states are interchangeable, and a common rule of dogfighting is to always exchange one for the other. Use your speed to gain alt - use your alt to gain speed. By converting one to the other, you minimize how much E you lose overall. Just like the money in your bank, once you spend your E, it is gone!

It is also important to note that because the two types of energy ARE interchangeable, a lower, fast plane and a higher, slower plane may have equal E. Think about it a second. If the low plane converts it's kinetic energy into potential energy by climbing, it may well end up the same altitude and speed as the plane above it. Similarly, the high, slow plane can convert it's potential energy into kinetic energy by diving and matching the speed and alt of the lower plane.

By the way - how often do you hear a pilot chiding another pilot for losing a "co-alt" fight? If one plane is 350 mph and the other is 250 mph, does being co-alt mean much? Notice the victor never says "Co-E"?

Offsetting your two forms of energy are two energy-draining forces: aero-resistance and gravity. Aero-resistance, or drag is caused by the friction of the air you displace; the harder you turn the more air you displace. The resulting loss of energy is referred to as "bleeding". Similarly, if you dive to build speed, then maintain level flight, you slowly lose speed as friction causes drag on your plane. Gravity is pretty obvious - the Earth wants you to come down!

While you can not control the force of gravity, you CAN manipulate drag. By refraining from hard turns unless absolutely needed and by eliminating extended periods of level flight after a dive, you can minimize your loss of E to drag.

Let's apply all this theory to a practical situation. You are faced with a near co-E enemy plane of similar capabilities, and you must turn after the merge. A common mistake of new pilots it to make a horizontal turn. When you make a horizontal turn, you bleed speed (kinetic energy) away as you fight drag and gravity, which in turn allows you to turn a tighter radius. The disadvantage to this approach is that the energy you have bled is gone for good. You have failed to convert your kinetic energy to potential energy by trading speed for alt.

However, if you examine the forces involved in a vertical turn ( 1/2 loop up, called an Immelman), you will see that you bleed speed away faster because the effects of gravity are increased. The reduction in speed (kinetic energy) allows your airframe to reach its optimum turn rate even faster than a horizontal turn. At this point, you might be thinking, "But wait, aren't we trying to CONSERVE energy?" Yes, you are - and you have! By using a vertical turn, you have converted some of your kinetic energy into potential energy - you now have more alt! You are higher and slower - which tightens your turn radius - and setup to convert your potential energy back into kinetic energy as you dive on your opponent below you. If he made a horizontal turn, you have gone from a co-E state to a position where you now have an E advantage! While he was recklessly throwing away his E in a horizontal turn, you wisely banked some of your energy and are rewarded by gaining the upper hand in the fight.

Understanding the way alt transfers to speed, speed transfer into alt, and the energy draining forces of drag and gravity is important to successful flying in Aces High. Proper management of E is a must in air combat. Not only will your choice of maneuvers will be limited by your E state, but also your ability to choose to engage on your terms. The plane with the most energy in a fight is the one with the most choices.

When you see a course talk about E, remember: Kinetic energy = speed. Potential energy = alt. You should strive to trade alt for speed and speed for alt. Working against you are the forces of drag and gravity. A constant underlying goal of every fight is to minimize the forces working against E while maximizing your transition of kinetic energy to potential energy and vice versa.

One final note regarding E management. Choosing to "dump" or shed energy is also a form of energy management. There are Air Combat techniques to use an opponents Energy against them (think of it as the ju jit zu form of ACM). While we do want to as a general rule try to conserve our E state, there may be times we need to dump E when in close combat. The most obvious example would be a faster plane on the six of a slower plane. If you are the faster plane, you need to keep some separation from the plane in front of you to prevent overshooting in front of them. If you have a great E advantage, you might just pull up into the vertical, extend, and re- engage at your leisure. However if your E advantage is too small to allow that choice, another method would be to "dump" E by throttling down, and using your control surfaces to create extra drag, with the goal of making the situation where you are co-speed. When the situation that caused you to dump E is under control, it is wise to go right back to banking your E as soon as possible in preparation for your next engagement.

Learning to apply the concepts of Energy Management in the arenas will not guarantee you will win your fights - but it WILL help give you positional and E-state advantages which will make winning your fights easier.