New Trigger-nometry

Flexible gunnery has been worked out to a mathematical formula, a system called "position firing" which is based upon speed, course, air density, deflection and other factors.

Every schoolboy knows that a hunter has to aim slightly in front of a flying duck — has to "lead" it — to allow for the distance the duck will have flown by the time the bullet reaches it. He also knows that if a newspaper boy on a bicycle aims directly at the customer's porch when he throws a rolled newspaper, it won't land on the porch, but probably in the bushes next door because he has failed to allow for the forward motion of the bicycle. Put these factors together, boost the speed up to hundreds of miles an hour, let the directions be forward, backward, up, down, toward you, away from you, or any combination of these directions, and you get the beginnings of an idea of the gunner's job.

Reprinted from Air Force, the official service journal of the US Army Air Forces.
This article was originally published in the May, 1944, issue of Flying Aces magazine, vol 47, no 2, p 44.
A PDF of this article is available.