BFM Maneuvering Tactics
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
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.
- 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°
- 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.
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.
- 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).
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:
- Line of Sight Rate (LOS) - The bandit's visual rate of movement across the
- 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
- 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).
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