INTERCEPT PROCEDURES TEXTBOOK
IP-17: LEAD COLLISION INTERCEPTS (ATTACK-REATTACKS)
Modern tactical doctrine does not always allow for purely rear quarter attacks. The fighter must
be able to employ forward quarter weapons to maintain a tactical advantage over adversaries. The
need for the aircrew to control the intercept, determine target aspect, establish collision bearing, and
accurately achieve proper firing parameters for all weapons remains the highest priority.
The fighter will apply the same basic procedures that have been utilized thus far in the reattack or
pursuit intercept. To provide guidance for an AIM-7 Sparrow, the fighter must place the radar in the
automatic tracking mode. Acquiring a lock (single target track/STT) will furnish the missile with the
continuous wave guidance necessary for successful employment.
Factors Affecting Success
targeting. As you will recall from your radar theory class, a doppler shift is the change in a pulse's
frequency caused by the downrange travel to or away from the fighter--also known as closure.
Therefore, targets with greater components of closure (lower target aspects) will have a higher
probability of being targeted accurately than those with lower components of closure (higher target
The "probability of kill", or Pk, is a measure of the likelihood that a missile will guide to, impact
and destroy the target. Higher closure rates (ROC) will increase the Pk for the Sparrow, as well as
the maximum range that this missile can be employed.
Closure rates, and hence max range, can be increased three ways: make a faster missile, fly the
aircraft faster or lower the target aspect. At VT-86, the aircraft speed will be limited and our
simulated missiles fly at a constant velocity. Therefore, a change in target aspect is the only way we
can affect maximum range and Pk.
Recall from IP-1 that lead pursuit places the fighter's nose in front of the target's nose to decrease
range and increase closure. Lead collision is still a form of lead pursuit, but the fighter's nose is
placed in front of the target by an amount that allows the faster missile to complete its own collision
intercept. Because the missile is faster than the target, it will fly a longer distance than the target to
the impact point (similar to a fighter with a speed advantage).