Weapons Delivery Principles And Procedures
make a larger correction. With rockets, your correction should be four times the deflection error.
For example, suppose that your pipper is 10 mils left of the aimpoint. Use your rudder to move the
pipper a total of 40 mils to the right, so that it will be 30 mils to the right of the aimpoint. With guns,
because the bullets have a higher initial velocity and have less tendency to align themselves with the
relative wind, a smaller correction is needed. Your correction should be 1.25 times the deflection
error. For example, if your pipper is 20 mils to the left of the desired aimpoint, use your rudder to
move it a total of 25 mils to the right, so that it will be 5 mils to the right of the aimpoint.
Corrections for Multiple Errors
In each of the foregoing discussions of error correction techniques, it was assumed that only one
dive parameter was in error, and that the rest were correct. For example, when we say that a 2-
degree error in dive angle will cause a 100-foot miss, we are assuming that the weapon is released
at the proper airspeed and altitude, wings level, and with correct g and the pipper on the aimpoint.
However, you will frequently find that one or more of your dive parameters is in error as you ap-
proach release. In such a case, the errors may be additive, or they may tend to cancel each other.
For instance, suppose that in a 30-degree bomb run, you notice that your dive angle is 1 degree
shallow and that your airspeed is 10 knots slow. If you have learned your error sensitivities properly,
you know that each of these errors will cause your hit to be 50 feet short, for a total of 100 feet, and
that you could correct by allowing the pipper to drift 100 feet past the target by release altitude. On
the other hand, if you happen to be 1 degree shallow and 10 knots fast, you know that these errors
cancel each other and no correction is needed. You can probably see, however, that trying to
mentally compute corrections for multiple errors during the few seconds before release could
become excessively complicated. Imagine trying to figure a correction for steep dive angle, fast
airspeed, and early sight picture. For now you are in a training environment, and you have the option
of aborting your run at any time. If you find yourself in a run that is really fouled up, dont drop.
All of the procedures given up to this point have assumed that there was no wind. In most cases,
however, there will be a wind at release altitude, and you will have to make some slight changes in
your roll-in point, tracking procedure, and release point. As we mentioned, the primary effect of wind
is to change the aircraft ground speed and direction. During the run, the motion of the aircraft
relative to the air mass is determined by the aircraft airspeed and heading. At the same time, if the
air mass is drifting, the aircraft will drift with it and will impart this drift to the weapon at release. For
example, if your aircraft is drifting to the left at 20 feet per second (12 knots) when you release a
bomb, then the bomb will continue to drift left at 20 feet per second all the way to impact. If you
release with the pipper on the bull, with all your dive parameters correct, and if the time of fall of the
bomb is 7 seconds, then your hit will be 140 feet left of the target (7 X 20 = 140). Any change of
wind between release and impact will have a negligible effect. It is easy to see, then, that you will
have to offset your final aimpoint to compensate for the wind at release altitude. In addition, you will
have to change your initial aimpoint and tracking procedure to compensate for the drift of the aircraft
during the run.
Because the wind will cause your aircraft to drift during the run, you must modify your tracking
technique. Figure 30 shows how the pipper moves during three stages of tracking: no-wind, pipper-
to-bull, and wind-corrected. No-wind tracking refers to the method given earlier and involves
tracking the pipper along the run-in line so that it reaches the target at release. Pipper-to-bull is a
simplified method designed to obtain a consistent grouping of hits downwind from the target. This
will demonstrate the effect of the wind so you can visualize corrective action. It is discussed below.