Figure 2 - P-8250122

INTERCEPT PROCEDURES TEXTBOOK

Effect on Target Aspect in Lead Collision

Lead collision comes at the expense of maintaining target aspect and angle off equal, but

opposite in direction, to each other. With angle off now less than target aspect, the bogey will

drift in such a way that TA increases over time.

Because the lead requirements are dependent upon target aspect, the fighter will be in the

proper position to fire the missile only momentarily. If any undue delay occurs, the fighter will

no longer be in position to satisfy the lead requirements, the dot will drift out of the circle, and

the fighter will miss a valid shot opportunity.

Figure 2

Establishing Lead Angle Off

Without the benefit of a fire control computer in the T-39N, the fighter must rely on a general

rule of thumb for establishing lead angle off. A knowledge of missile and aircraft speeds

indicates that for target aspects of 0 to 47 degrees, the lead required is roughly one-half the target

aspect. For example, with 30 R TA, the fighter would need to have its nose pointed 15 in front

of the bogey (15L AO) at Rmax.

Figure 3

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