Figure 12 - P-8250058

INTERCEPT PROCEDURES TEXTBOOK

Figure 12

Rounding

In the previous examples the final collision course has always been a cardinal heading (a

heading that ends in a zero, i.e., 240, 050, 120, etc). In all subsequent problems, the collision

course will still be a cardinal heading. This is the result of rounding.

Before the bogey bearing or angle off is used to make a collision course correction, it is first

rounded off to the nearest five or zero using the following scale:

0, 1, or 2 rounds to 0

3-7

rounds to 5

8, 9, or 0 rounds to 0

The bogey heading, and hence the bogey reciprocal, is always a cardinal heading in this

syllabus. Setting AO equal to but opposite in direction to the TA will always result in a cardinal

heading for a collision course. If the RIO/WSO comes up with a collision course that does not

end in a zero, then the answer must be wrong.

Rounding permits faster math for faster CCC's and causes fewer arithmetic errors. It is the

weapons officer's responsibility to round the bogey bearing call from GCI or the AO from the

scope.