by Andy Bush
Congratulations for having made it so far!! After countless words and diagrams, we finally are at the point where the ‘rubber meets the road’…or should I say where the ‘bullets meet the target’?!!
In this last section, we are going to look at each type of sight ‘up close and personal.’ Our objective is to describe the operation of these sights in such a manner that you can take the info and apply it directly to your favorite sim. All the little bits and pieces of info in Parts One and Two are going to be important in helping you understand how to get the gun on the target, so if you haven’t had a chance to look over those sections, it might be a good idea to do so before you start this one.
We’ll begin with a quick review of the bullet stream concept. The single most important thing for you to get out of this is an appreciation for the three dimensional aspect of that bullet stream. If you can ‘see’ this concept in your mind, then understanding what is or is not a valid firing solution is a whole bunch easier.
Plane of Symmetry
The plane of symmetry is another one of those terms that we use when we try to explain what we’re looking at when we use a gunsight. 99% of understanding and using a gunsight is in the understanding of what the gunsight display means with reference to the bullet stream. We have to establish a common frame of reference to do this. The plane of symmetry is a good place to start. The plane of symmetry is the vertical plane extending along the longitudinal axis and perpendicular to the rudder. It looks like this.
A common way of visualizing the plane of symmetry is to use a line coming out of the top of our canopy that is perpendicular to the wings and fuselage. You can also think of the plane of symmetry as your lift line. Some like to use the vertical stabilizer to represent the lift line…that’s OK as long as the thing is vertical, and not canted off to one side or the other as in the F-18! The significance of this concept to gun employment is that the gun line lies in this plane, and that the bullet stream begins in this plane.