Great question… near and dear to my field artillery heart!
Unfortunately there are no specific rules with regard to direct fire. Typically a unit will practice direct fire about once a year. When funding is tight you may not get this practice. A field artillery crew typically switches to direct fire mode when they can visualize the enemy within 2,000 meters but this is dependent upon terrain and other elements. In addition direct fire would be most effective when the gun crew can track and fire at a target faster than Fire Direction Control can provide mission data. With regard to use of the AT4’s these are usually only used to cover choke points and/or against lightly armed or heavy armed vehicles. They are also effective for clearing bunkers or other hides.
There are no cut-and-dry, by-the-book answers. If you are firing direct fire with an artillery piece things have gotten bad quick. Using direct fire is your last defensive line.
Comments
Ian Kozelsky
what is the name? I was FDO but I can’t remember the name of the direct fire option used in Vietnam for 2000 meters or less. had some silly name like Sally or something…
Mark Gerecht
Beehive round
Mark Gerecht
Most likely called a Beehive round.
Van
Oh finally, a good FA question!
The range at which you switch to direct fire is entirely dependent upon where you are emplaced. When you emplace, part of position improvement is filling out the range card. This should identify, among other things, what constitutes your final protective line. The FPL (or, the target designated for Final Protective Fire) represents the closest distance the enemy can approach to your position. This will obviously be different for each emplacement, and it should be determined by your section chief and platoon sergeant, as well as your gunnery sergeant (or whatever NCO is responsible for advance party and the platoon defense diagram).
Ideally, you should never be direct firing stuff that comes toward your FPL, because as artillery we don’t go around seeking direct engagements with the enemy. You should be trying to break contact as quickly as possible and then use maneuver to locate another suitable position from which you can provide supporting fires.