60-MM MORTAR TACTICAL EMPLOYMENT In the defense, final protective fire of a single mortar covers an area of approximately 50 by 50 meters. A FPF may be located within 60 meters of the FEBA. Thus the 60-mm mortar can cover small gaps or dead space in the machine gun FPF close to the FEBA. Firing positions for mortars should be located between 150 and 300 meters to the rear of the FEBA.

Communications Communication to the mortar platoon starts at the Fire Direction Center (FDC). Companies requesting a fire mission do so by contacting (FDC). The FDC will plot the fire mission and issue fire commands to the mortar section leader responsible for the mortar gun crew. Forward observers (FOs) assigned to the mortar platoon communicate with the FDC directly. FDC must seek approval for all fire missions from the Fire Support Coordinator (FSC) located in the COC.

Sectors of Observation Sectors of observations are critical for mortar fire to be effective. The mortar platoon is not assigned a sector of fire but must be able to provide coverage throughout the battalion security area. Rifle platoon commanders must ensure that their assigned battle area is covered by overlapping sectors of observation. Forward observers (FOs) from the mortar platoon are usually assigned this task, but it may be necessary for the rifle companies to assist the FOs. Personnel from the rifle companies assigned as FOs must be able to call in a fire mission and do so via the platoon commander and the company CP.

Rate and Duration of Fire In the absence of any instructions, the normal rate of fire is nine rounds per minute for the first 2 minutes and six rounds per minute after that for the duration of final protective fire (FPF). The FDC chief will normally specify the number of rounds to be expended on each target to the section leader. The COC, upon approval from the battalion commander, sets the number of rounds to be fired for FPF. Consideration is given to the ammunition on hand, nonorganic support available, anticipated resupply schedule, area to be covered, and enemy activity.

SUPPLEMENTARY MISSIONS Both the machine gun squad and the assault squad may be positioned and employed in performing supplementary missions in defense.

Machine Guns Machine gun squads, employed on the FEBA or in the reserve area, prepare supplementary positions from which to cover sectors of fire different from their primary sectors. Missions are usually based upon an enemy penetration of an adjaent company or platoon and to provide all-around defense.

AT4 Assault squads, whose primary missions are to cover avenues of apprach to the FEBA, may be required to prepare supplementary positions. The supplementary positions are to cover avenues into the flanks and rear of the company. Assault squads support the defense by fire from planned supplementary positions when an armor threat fails to develop.

60-mm Mortars Supplementary positions are infrequently established for a 60-mm mortar squad section. However, fire within the battle area is planned to provide for supporting frontline rifle units when they are forced to move to supplementary positions.

RANGE CARDS Once a machine gun team is deployed in a defensive position and the gun laid, the squad leader must ensure that range cards have been completed. Two sets of range cards must be made for every fighting position. Range cards are very important and are used for several purposes. The squad leader forwards one copy as soon as possible to the platoon commander. The platoon commander ensures the card is accurate and then forwards it on to the company CP. Range cards are the basis for the fire plan of the company. All supporting fire, security sectors, and defensive coordination are planned using machine gun fire as the base from which to build.

The second copy of the range card will be kept by the gun team. The card is used by members of the gun team to fire at predetermined targets or to help in range estimations to other targets. Range cards may be passed on to a relieving battalion. Patrols from companies or other units may want to look at the range cards to identify final protective lines. Patrols need to know of any dead space to ensure that they are clear of infiltrators and where to take cover during an FPF.