Unit 4: Displacement and Counterturns

INTERCEPT PROCEDURES TEXTBOOK

UNIT 4: DISPLACEMENT AND COUNTERTURNS

IP-9: DISPLACEMENT TURN FUNDAMENTALS

Lateral Displacement / Turning Room

Obviously, a collision course will not be continued all the way to a midair. It will be broken-

off at some range to permit the fighter to execute a turn in order to arrive in the bogey's rear

quarter. By knowing TA and slant range, we can then calculate lateral displacement, also known

as turning room.

The weapons officer must compute TA correctly prior to breaking the collision course.

Therefore, here at VT-86, you will stop making collision course corrections 2 miles prior to the

displacement turn. This will allow time to observe drift and, if necessary, update TA prior to

commencing the displacement turn.

The displacement turn (DT) is the turn made by the fighter to break collision course. It will

reorient the flight path in order to gain, maintain, or slow the rate of loss of lateral separation.

Following extensive, and often dangerous, flight testing, we pushed the T-39N to the edge of

the envelope and concluded that 20,000 feet (roughly 3 1/2 nm) is the ideal amount of turning

room for the reattack intercept. As you can imagine, the T-39N will need more lateral

displacement than high performance fighters.

Remember the lateral displacement formula:

TA x SR x 100 = LD

An example of the amount of turning room available for certain target aspects is shown in

Figure 1.

5 TA x 10 nm x 100 = 5,000' LD: not enough turning room

20 TA x 10 nm x 100 = 20,000' LD: adequate turning room

30 TA x 10 nm x 100 = 30,000' LD: too much turning room