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      BFM Maneuvering Tactics


      Energy Management

           Energy, also known as 'E', in BFM is a relative term.  The ability to maintain a high-energy state in air combat is very hard to do, but essential for survival.  The energy your aircraft possesses at any given time is called your energy rate or Ps.

           Managing energy is the process of balancing the forces of drag, lift, thrust, and gravity (please see the module "Flight Basics" for more information).  Your energy state is a combination of kinetic energy and potential energy.  Kinetic energy is energy that you are presently exerting, i.e. - the motion of the aircraft, thrust, speed, etc.  Potential energy is stored energy or something that can be turned in to kinetic energy such as altitude or JP5 (fuel). 'E' is also exerted differently at different altitudes. Consider the bank analogy. When you first open an account, you are requested to make a deposit. You now have money in the bank to spend.  This what happens as you are flying along at altitude. Say your flying cruise at 450kts at angels15 (15,000ft.).  Your present altitude and speed are deposited in the bank. You can deposit more in the bank by gaining altitude, but you will initially spend JP5 for altitude.  After you gain altitude, you can fly straight and level and regain your speed.  Now you have even more potential 'e' banked.  Now say you meet Colonel Tomb (know who that is?) in the air and he wants to put holes in your jet. At the merge (side-by-side pass), you need to turn to get at him. You will now need to spend some of that money (e) to get the nose around. Your thrust (fuel) is potential energy and you will have to burn some to maintain corner velocity (the speed that gives you the best turn performance of the jet) and get around. Likewise, you can extend (dive) to gain lost 'e'. You will basically spend 'e' every time you perform a maneuver that requires more 'e' than your engines are producing. Once you spend all of your 'e', you are a grape about to be squashed. This holds true for the opposing fighter too.

        You must maintain your energy level to be able to out turn or stay with the bandit.  There are several ways to turn: horizontal, vertical, and a combination of the two.  If you maintain a constant g turn in the horizontal (the initial turn will cost you), you risk spending little energy, but turn your nose up and the cash resister starts ringing.  Try to maintain your fight laterally if at all possible.  If you do have the energy advantage though, you may want to consider taking the fight vertical.  In this case, let me tell you about 'e' in the vertical. You get the worst turn performance at the beginning of the up turn.  This is because gravity is against you and pushing your aircraft down.  As you get closer to the top, the turn arc increases because your 'e' is low.  As you start down though, you have gravity on your side and will get the best turn radius as g pulls you down.  The arc will start to flatten out a little to maintain a constant g eventually making the turn look like an upside down egg!  This is known as "The Energy Egg".  The nose high fighter usually has the advantage.  Always remember "Low and slow means your out of dough".  As I said before, always maintain a high-energy state.  Remember that you can turn potential energy in to kinetic energy.  If you would like more info, download the word document "Air Combat Energy Management".

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