INTERCEPT PROCEDURES TEXTBOOK
(3) If a bogey is not on collision bearing, it will always drift away from collision bearing at
a predictable rate, based on range and degrees off collision bearing.
(4) As the range decreases, the degrees a bogey is off collision bearing increases, and the
rate at which the bogey will drift increases.
Step 1: Starting Point: Unknowns
The first step is to determine an initial fighter heading. Steady on a heading with the bogey
bearing on the nose based on GCI information given at the start of the fight. The starting point
for drift analysis places the bogey on the fighter's nose, estimating a zero cut. It is no longer
necessary to steady up on a heading ending in zero. If the bogey bears 337º, then the fighter
should steady on a heading of 337º. If GCI indicates drift while in the turn, update the steady
heading accordingly. If GCI is giving Bullseye calls, the fighter must correlate roughly where
the bogey is, search for and gain a radar contact, and then steady up with the contact on the
fighter's nose. Once steadied up with the bogey on the nose, there will be no further heading
changes until the completion of step 2.
Step 2: Drift Analysis
The single most important piece of information required to successfully intercept a target
with an unknown heading is DOP! Of course, accurate TA determination is ideal and required
for a forward quarter shot opportunity. However, a successful reattack can be accomplished
merely with correct knowledge of DOP. Even if TAA is way off, with a displacement turn made
on the correct side of flight path, the counterturn may be adjusted for hot or cold situations
enough to arrive in the rear quarter in LAR for a F-2.
Once the fighter is wings level, the scope can be used for drift analysis. The weapons officer
will first mentally correlate the radar contact with GCI information. Then, to be sure that the
analysis is accurate, analyze the drift for a sufficient amount of time (usually 2-4nm) before
making a correction. If the bogey drifts to the right, there is right TA and the DOP is left-to-
right. If the bogey drifts to the left, there is left TA and the DOP is right-to-left. If the bogey
does not drift at all, TA is zero or close to it, and the fighter should remain on the present
Drift Analysis from GCI, Determining DOP
If radar contact is not established by 25nm, the operator may tell the controller to "Go
tactical" or "Go BRA for ______(own callsign)," at which time GCI should provide tactical BRA
calls for the fighter. Your controller will call drift according to the picture on his own radar
scope. Use this GCI information to determine DOP. If radar contact is established after going
tactical, continue to analyze the DOP using the GCI information and the scope. If the target
appears to be drifting in a direction contrary to GCI (while wings level), then make the
correction according to the observed drift on the radar scope.