- Angle-Off (also called Track Crossing Angle or Heading Crossing Angle) - The angle formed by the extension of the longitudinal axis of two aircraft. The angle is measured from the intersection of the attacker's present heading, and the defender's present heading in relation to the defender's 6 o'clock. If your jet and the bogey are flying parallel to each other, your angle-off is 0°
- Aspect Angle - Angle between defender's longitudinal axis and the line of sight to the attacker. The angle is measured from defenders 6 o'clock which is 0° (zero) and the nose of the aircraft being 180°. Aspect is measured with respect to the right or left of the bandit's tail. Example: If you are on the bandits left, you would have left aspect with the number of degrees dependent on where you where in relation to the bandit. If you were head on, you would be at 180° aspect. If you were on the right side of the bandit perpendicular to his aircraft, you would be at 90° right aspect. Note this: The attacker heading is irrelevant. That means that no matter which direction you are flying in, 60°R aspect to the bandit is 60° aspect.
- Range - The distance from the attacker to the defender measured in feet out to one nautical mile (1nm equal to 6,000 feet - jeez, that was easy, huh?) and then in nautical miles after 6,000ft.
- Lag Pursuit - Flight path usually used to approach the bandit and maneuver on his six. You know your flying lag when the flight path marker is behind or below the bandit. Lag pursuit is also used when the bandit maneuvers out of plane (not in the same plane of motion, i.e. - horizontal, vertical, etc.). In order to fly lag on a bandit, you had better have a jet that can out turn the other or you will get stuck in lag pursuit and not be able to pull for the shot.
- Pure Pursuit - When the nose of your jet is pointed directly at the bogey. This is when the flight path marker is pointing directly on the bogey. Pure pursuit is mainly used when you want to shoot the bandit with a missile. Be aware that maintaining a pure pursuit path for to long WILL lead to an overshoot! Only use this course if you plan on shooting the bandit.
- Lead Pursuit - Flight path taken to close on the bogey. The flight path marker will be above or in front of the bogey. Lead is used for tracking and snapshot guns shots. Be careful though, lead will also resort to an overshoot if you don't keep a handle on your overtake speed. You also must have a better turn rate than the bandit or you'll never be able to pull lead and get a tracking guns shot. This where energy comes in (we'll talk about that later).
- Line of Sight Rate (LOS) - The bandit's visual rate of movement across the canopy.
- Velocity Vector - A line representing the current direction and magnitude of the path of travel.
- Split-Plane Maneuvering (also called Out-of-Plane maneuvering) - Aircraft or elements maneuvering in relation to one another, but in different planes and/or altitudes. Examples are one jet maneuvering lateral and the other vertical.
- Closure (Vc) - Relative velocity of one aircraft in relation to another or closure between fighter and target expressed in knots, relative velocity. To make it easier, add the smash of the two jets together when they are flying towards each other or the difference when flying away from each other. This is how you get the closure rate. Example: jet 1 doing 400 kts + jet 2 doing 500 kts = 900kts closure. (See Head-on BFM section)
- Jink or Jinking - Aircraft maneuvers designed to change the flight path of the aircraft in all planes at random intervals (usually to negate a gun attack).
Definitions & Geometry
Lets get one thing out of the way first. All headings to or from the bogey are in relation to either degrees or a clock position. Let me explain the clock position thing here. When you are sitting in your cockpit, the longitudinal line (an imaginary line) extending through the nose and tail represent the 12:00 o'clock (nose of the plane) and 6:00 o'clock (tail of the aircraft) position of a clock. Likewise, the lateral line extending from wingtip to wingtip represents 9:00 o'clock (left wingtip) and 3:00 o'clock (right wingtip). So if you see "on your six", it means on your tail!
The first buzzword is Positional Geometry (PG). PG is a way of describing where your jet is in relation to the bogey's jet. There are three terms that make up PG.
The next buzzword is Attack Geometry (AG). These are also in your training videos. AG defines where your jets nose is pointing in relation to the bogey's jet as you converge on the bandit. There are also three terms in AG.
Last but not least is the Weapons Envelope (WE). The WE determines the area around a bandit where your weapons will be effective. There are three envelopes, but only two are needed for this discussion. Both envelopes use two separate values called Rmax and Rmin. Rmax is the maximum range that a weapon can be deployed and still maintain the kill. The farther the range, the smaller the probability of kill or PK (remember this). Rmin is the minimum range that a weapon can be deployed to get it off the rail. Rmin usually only deals with missile shots as gun shots do not have an Rmin. But remember, you can eat pieces of the enemy's jet for breakfast if you are too close. Rmin/Rmax for missiles will be discussed in the A2A weapons section of the trainer. Here, Rmax for the gun is approximately 4500' from the front quarter and 2500' in the rear quarter. Bullets also have to fight the effects of speed and gravity.
Miscellaneous terms that deal with other aspects of air combat:
