Military

CHAPTER 4

CALL FOR FIRE

Section I

ELEMENTS OF THE CALL FOR FIRE

4-1. DESCRIPTION

a. A call for fire (CFF) is a concise message prepared by the observer. It contains all information needed by the FDC to determine the method of target attack. It is a request for fire, not an order. It must be sent quickly but clearly enough that it can be understood, recorded, and read back, without error, by the FDC recorder. The observer should tell the RATELO that he has seen a target so the RATELO can start the call for fire while the target location is being determined. Information is sent as it is determined rather than waiting until a complete call for fire has been prepared.

b. Regardless of the method of target location used, the normal call for fire is sent in three parts consisting of six elements. The six elements, in the sequence in which they are transmitted, are discussed in paragraphs 4-2 through 4-7. They are as follows:

• Observer identification.

• Warning order.

• Target location.

• Target description.

• Method of engagement.

• Method of fire and control.

c. The three transmissions in a call for fire are as follows:

• Observer identification and warning order.

• Target location.

• Description of target, method of engagement, and method of fire and control.

There is a break after each transmission, and the FDC reads back the data.

d. DA Form 5429-R (Conduct of Fire) is used by the observer in conducting fire missions and recording mission data. The front page, Section I, is organized to help him record his call for fire and subsequent adjustment data. Section II, on the back of the form, is used to record registration data. Portions of DA Form 5429-R are shown with examples throughout this publication. Reproducible copies are at the back of this manual.

4-2. OBSERVER IDENTIFICATION

This element of the call for fire tells the FDC who is calling for fire.

4-3. WARNING ORDER

The warning order clears the net for the fire mission and tells the FDC the type of mission and the type of target location that will be used. The warning order consists of the type of mission, the size of the element to fire for effect, and the method of target location. It is a request for fire unless prior authority has been given to order fire.

a. Type of Mission.

(1) Adjust Fire. When the observer believes that an adjustment must be made (because of questionable target location or lack of registration corrections), he announces ADJUST FIRE.

(2) Fire for Effect. The observer should always strive for first-round FFE. The accuracy required to fire for effect depends on the accuracy of target location and the ammunition being used. When the observer is certain that the target location is accurate and that the first volley should have the desired effect on the target so that little or no adjustment is required, he announces FIRE FOR EFFECT.

(3) Suppression. To quickly bring fire on a target that is not active, the observer announces SUPPRESS (followed by the target identification). Suppression (S) missions are normally fired on preplanned targets, and a duration is associated with the call for fire.

(4) Immediate Suppression and Immediate Smoke. When engaging a planned target or target of opportunity that has taken friendly maneuver or aerial elements under fire, the observer announces IMMEDIATE SUPPRESSION or IMMEDIATE SMOKE (followed by the target location). Though the grid method of target location is the most common, any method of target location may be used in firing an immediate suppression or immediate smoke mission.

b. Size of Element to Fire for Effect. The observer may request the size of the unit to fire for effect; for example, BATTALION. Usually, he does this by announcing the last letter in the battalion FDC's call sign. For example, T6H24 is announced H. The observer should never refer to a battery or other unit in the clear. He should refer to it by call sign. If the observer says nothing about the size of the element to fire, the battalion FDC makes that decision. It is based on the target attack guidance received and the graphical munitions effectiveness table (GMET) or joint munitions effectiveness manual (JMEM) solution.

c. Method of Target Location.

(1) Polar Plot. If the target is located by the polar plot method of target location, the observer announces POLAR; for example, ADJUST FIRE, POLAR, OVER.

(2) Laser Polar Plot. The FDC needs to know as quickly as possible if the observer is using a laser. Although the data are still polar, the backup computer system (BUCS) uses a different format from the fire mission index. From the initial transmission of the call for fire, the FDC will know which of its four mission formats to display; for example, ADJUST FIRE, LASER POLAR, OVER.

(3) Shift From a Known Point. If the target is located by the shift from a known point method of target location, the observer announces SHIFT (followed by the known point); for example, ADJUST FIRE, SHIFT KNOWN POINT 1, OVER.

(4) Grid. If the grid method of target location is being used, the word grid is not announced; for example, ADJUST FIRE, OVER.

4-4. TARGET LOCATION

This element enables the FDC to plot the location of the target to determine firing data.

a. In a grid mission, six-place grids normally are sent. Eight-place grids should be sent for registration points or other points for which greater accuracy is required. The OT direction normally will be sent after the entire initial call for fire, since it is not needed by the FDC to locate the target.

b. In a shift from a known point mission (Figure 4-1), the point or target from which the shift will be made is sent in the warning order. The point must be known to both the observer and the FDC. The observer then sends the OT direction. Normally, it is sent in mils. However, the FDC can accept degrees or cardinal directions, whichever is specified by the observer. The corrections are sent next:

• The lateral shift (how far left or right the target is) from the known point.

• The range shift (how much farther [ADD] or closer [DROP] the target is in relation to the known point, to the nearest 100 meters).

• The vertical shift (how much the target is above [UP] or below [DOWN] the altitude of the known point, to the nearest 5 meters). (The vertical shift is ignored unless it exceeds 30 meters.)

Figure 4-1. SHIFT FROM A KNOWN POINT

c. In a polar plot mission, the word polar in the warning order alerts the FDC that the target will be located with respect to the observer's position. The observer's location must be known to the FDC. The observer then sends the direction and distance. A vertical shift tells the FDC how far, in meters, the target is located above or below the observer's location. Vertical shift may also be described by a vertical angle (VA), in mils, relative to the observer's location.

4-5. TARGET DESCRIPTION

The observer must describe the target in enough detail that the FDC can determine the amount and type of ammunition to use. The FDC selects different ammunition for different types of targets. The observer should be brief but accurate. The description should contain the following:

• What the target is (troops, equipment, supply dump, trucks, and so forth).

• What the target is doing (digging in, in an assembly area, and so forth).

• The number of elements in the target (squad, platoon, three trucks, six tanks, and so forth).

• The degree of protection (in open, in foxholes, in bunkers with overhead protection, and so forth).

• The target size and shape if these are significant. If the target is rectangular, the length and width (in meters) and the attitude (azimuth of the long axis 0000-3199) to the nearest 100 mils should be given; for example, 400 BY 200, ATTITUDE 2800. If the target is circular, the radius should be given; for example, RADIUS 200. Linear targets may be described by length, width, and attitude.

4-6. METHOD OF ENGAGEMENT

The observer may indicate how he wants to attack the target. This element consists of the type of adjustment, trajectory, ammunition, and distribution. DANGER CLOSE and MARK are included as appropriate.

a. Type of Adjustment. Two types of adjustment may be employed-precision and area. Unless precision fire is specified, area fire will be used.

(1) Precision fire is conducted with one weapon on a point target. It is used either to obtain registration corrections or to destroy a target. When the mission is a registration, it is initiated by the FDC with a message to observer. If the target is to be destroyed, the observer announces DESTRUCTION.

(2) Area fire is used to attack an area target. Since many area targets are mobile, the adjustment should be as quick as possible, consistent with accuracy, to keep the target from escaping. A well-defined point at or near the center of the area to be attacked should be selected and used as an aiming point. This point is called the adjusting point during adjust fire missions. To achieve surprise, fire may be adjusted on an auxiliary adjusting point and, after adjustment is completed, the fire for effect shifted to the target. Normally, adjustment on an area target is conducted with one adjusting weapon.

b. Danger Close. DANGER CLOSE is included in the method of engagement when the target is (rounds will impact) within 600 meters of friendly troops for mortar and artillery, 750 meters for naval guns 5-inch and smaller, and 1,000 meters for naval guns larger than 5-inch. For naval 16-inch ICM, danger close is 2,000 meters.

c. Mark. MARK is included in the method of engagement to indicate that the observer is going to call for rounds for either of the following reasons:

• To orient himself in his zone of observation.

• To indicate targets to ground troops, aircraft, or fire support.

d. Trajectory. Low-angle fire is standard for field artillery. If high-angle fire is desired, it is requested immediately after the type of engagement. If high angle is not specified, low angle will (normally) be used. If the firing unit determines that high angle must be used to attack a target, the unit must inform the observer that high angle will be used. Mortars fire only high angle.

e. Ammunition. The observer may request any type of ammunition during the adjustment or the FFE phase of his mission. Shell HE with fuze quick is normally used in adjustment. If that is what the observer desires, he need not request it in his call for fire. If the observer does not request a shell-fuze in effect, the fire direction officer (FDO) determines the shell-fuze combination. Unit SOP may designate a standard shell-fuze combination. (See also Section II.)

(1) Projectile. Examples of requests for other than HE projectile are ILLUMINATION, ICM, and SMOKE.

(2) Fuze. Most missions are fired with fuze quick during the adjustment phase. If fuze quick is desired or if a projectile that has only one fuze is requested, fuze is not indicated. Illuminating, ICM, and smoke projectiles are fuzed with time fuzes; therefore, when the observer requests ILLUMINATION, ICM, or SMOKE, he does not announce TIME.

(3) Volume of Fire. The observer may request the number of rounds to be fired by the weapons firing in effect. For example, 3 ROUNDS indicates that the firing unit will fire three volleys.

f. Distribution. The observer may control the pattern of bursts in the target area. This pattern of bursts is called a sheaf Unless otherwise requested, the battery, computer system (BCS) assumes a circular target with a 100-meter radius. The BCS determines individual weapon aiming points to distribute the bursts for best coverage of this type of target. A converged sheaf places all rounds on a specific point and is used for small, hard targets. Special sheafs of any length and width may be requested. An open sheaf separates the bursts by the maximum effective burst width of the shell fired. If target length and width are given, attitude also must be given. If target length is equal to or greater than five times the target width, the BCS assumes a linear target. The mortar ballistic computer assumes the target is linear and fires a parallel sheaf unless a special sheaf is requested.

4-7. METHOD OF FIRE AND CONTROL

The method of fire and control element indicates the desired manner of attacking the target, whether the observer wants to control the time of delivery of fire, and whether he can observe the target. Methods of control at my command (AMC) and time on target (TOT) are especially useful in massing fires. The AMC and TOT missions achieve surprise and maximize the effects of the initial volley on a target. When used by the observer, these methods of control can reduce the sporadic engagement of the target, or "popcorn effect," which can be the result of rounds fired when ready. Methods of fire and control are announced by the observer by use of the terms discussed below.

a. Method of Fire. In area fire, the adjustment normally is conducted with one howitzer or with the center gun of a mortar platoon or section. If for any reason the observer determines that PLATOON RIGHT (LEFT) will be more appropriate, he may request it. (Adjusting at extreme distances may be easier with two guns firing.) The normal interval of time between rounds fired by a platoon or battery right (left) is 5 seconds. If the observer wants some other interval, he may so specify.

b. Method of Control.

(1) At My Command. If the observer wishes to control the time of delivery of fire, he includes AT MY COMMAND in the method of control. When the pieces are ready to fire, the FDC announces PLATOON (or BATTERY or BATTALION) IS READY, OVER. (Call signs are used.) The observer announces FIRE when he is ready for the pieces to fire. AT MY COMMAND remains in effect throughout the mission until the observer announces CANCEL AT MY COMMAND, OVER.

(2) Cannot Observe. CANNOT OBSERVE indicates that the observer cannot see the target (because of vegetation, terrain, weather, or smoke); however, he has reason to believe that a target exists at the given location and that it is important enough to justify firing on it without adjustment.

(3) Time on Target. The observer may tell the FDC when he wants the rounds to impact by requesting TIME ON TARGET (so many) MINUTES FROM...NOW, OVER or TIME ON TARGET 0859, OVER. The FO must conduct a time hack to ensure that 0859 on his watch is 0859 on the FDC's watch.

(4) Continuous Illumination. If no interval is given by the observer, the FDC determines the interval by the burning time of the illuminating ammunition in use. If any other interval is required, it is indicated in seconds.

(5) Coordinated Illumination. The observer may order the interval between illuminating and HE shells, in seconds, to achieve a time of impact of the HE coincident with optimum illumination; or he may use normal AT MY COMMAND procedures.

(6) Cease Loading. The command CEASE LOADING is used during firing of two or more rounds to indicate the suspension of loading rounds into the gun(s). The gun sections may fire any rounds that have already been loaded.

(7) Check Firing. CHECK FIRING is used to cause an immediate halt in firing.

(8) Continuous Fire. In field artillery, mortars, and naval gunfire, continuous fire means loading and firing as rapidly as possible, consistent with accuracy, within the prescribed rate of fire for the equipment. Firing will continue until suspended by the command CEASE LOADING or CHECK FIRING.

(9) Repeat. REPEAT can be given during adjustment or FFE missions.

(a) During Adjustment. REPEAT means fire another round(s) with the last data and adjust for any change in ammunition if necessary. REPEAT is not sent in the initial call for fire.

(b) During Fire for Effect. REPEAT means fire the same number of rounds using the same method of fire for effect as last fired. Changes in the number of guns, the previous corrections, the interval, or the ammunition may be requested.

(10) Followed By. This is part of a term used to indicate a change in the rate of fire, in the type of ammunition, or in another order for fire for effect; for example, WP FOLLOWED BY HE.

4-8. CORRECTIONS OF ERRORS

a. Errors are sometimes made in transmitting data or by the FDC personnel in reading back the data. If the observer realizes that he has made an error in his transmission or that the FDC has made an error in the read back, he announces CORRECTION and transmits the correct data.

b. When an error has been made in a subelement and the correction of that subelement will affect other transmitted data, CORRECTION is announced. Then the correct subelement and all affected data are transmitted in the proper sequence.

4-9. CALLS FOR FIRE FROM HEADQUARTERS HIGHER THAN BATTALION

Calls for fire from higher headquarters and from the observer are similar in format. The call for fire from higher headquarters may specify the unit to fire for effect. However, the observer's call for fire can only request the firing unit. An example of a call for fire from higher headquarters is shown below.

4-10. MESSAGE TO OBSERVER

After the FDC receives the call for fire, it determines how the target will be attacked. That decision is announced to the observer in the form of a message to observer (MTO). The MTO consists of the four items discussed below.

a. Unit(s) to Fire. The battery (or batteries) that will fire the mission is (are) announced. If the battalion is firing in effect with one battery adjusting, the FDC designates the FFE unit (battalion) and the adjusting unit by using the last letter of the call sign.

b. Changes to the Call for Fire. Any change to what the observer requested in the call for fire is announced.

c. Number of Rounds. The number of rounds per tube in fire for effect is announced; for example, T, G, VT IN EFFECT, 4 ROUNDS.

d. Target Number. A target number is assigned to each mission to facilitate processing of subsequent corrections; for example, T, G, VT IN EFFECT, 4 ROUNDS, AA7732, OVER.

4-11. ADDITIONAL INFORMATION

The additional information shown below normally is transmitted separately from the MTO.

a. Probable Error in Range. If probable error in range (PEr) is 38 meters or greater during a normal mission, the FDC informs the observer. If PEr is 25 meters or greater in a precision registration, the FDC informs the observer.

b. Angle T. Angle T is sent to the observer when it is 500 mils or greater or when requested.

c. Time of Flight. Time of flight is sent to an observer during a moving target mission, during an aerial observer mission, during a high-angle mission, and for shell HE in a coordinated illumination mission when using BY SHELL AT MY COMMAND, or when requested.

4-12. AUTHENTICATION

a. When nonsecure communications are used and excluding unique fire support operations (such as suppressive fires posture), challenge and reply authentication is considered a normal element of initial requests for indirect fire. The FDC challenges the FO after the last read back of the fire request (see examples in paragraph 4-13). The FO transmits the correct authentication reply to the FDC immediately following the challenge. Authentication replies exceeding 20 seconds are automatically suspect and a basis for rechallenge. Subsequent adjustment of fire or immediate engagement of additional targets by the FO originating the initial fire request normally would not require continued challenge by the FDC. FM 24-35 provides information on authentication procedures.

b. Two methods of authentication are authorized for use: challenge and reply and transmission (which is commonly referred to as self-authentication). The operational distinction between the two is that challenge and reply requires two-way communications, whereas transmission authentication does not. Challenge and reply authentication will be used whenever possible. Transmission authentication will be used if authentication is required and it is not possible or desirable for the receiving station to reply; for example, imposed radio silence, final protective fire, and immediate suppression.

c. The FO is given a transmission authentication table as per unit standing operating procedures (SOP). The transmission authentication table consists of 40 columns of authenticators with S authenticators in each column. For immediate suppression, the FO must use the column assigned to his supporting unit. Authenticators from the numbered columns of the transmission authentication table should be used only once. The first unused authenticator in the assigned column is used, and a line is drawn through that authenticator to preclude its reuse.

4-13. SAMPLE MISSIONS

The following are sample calls for fire and FDC responses for various type missions.

                              EXAMPLES

                        FIRE MISSION (GRID)

                       Initial Fire Request

    Observer                                        FDC

Z57 THIS IS Z71,
ADJUST FIRE, OVER.
                                              THIS IS Z57, ADJUST
                                              FIRE, OUT.
GRID NK180513, OVER.
                                              GRID NK180513, OUT.
INFANTRY PLATOON
IN TH OPEN, ICM
IN EFFECT, OVER.
                                              INFANTRY PLATOON IN
                                              THE OPEN, ICM
                                              IN EFFECT,
                                              AUTHENTICATE
                                              PAPA BRAVO, OVER.
I AUTHENTICATE
CHARLIE, OUT.

                          Message to Observer

    Observer                                        FDC
                                              Z, 2 ROUNDS, TARGET
                                              AF1027, OVER.

Z, 2 ROUNDS, TARGET
AF1027, OUT.

DIRECTION 1680, OVER.
                                              DIRECTION 1680, OUT.

                             FIRE MISSION (SHIFT)
                             Initial Fire Request

    Observer                                           FDC

H66 THIS IS H44,
ADJUST FIRE, SHIFT
AA7733, OVER.
                                              THIS IS H66, ADUST
                                              FIRE, SHIFT AA7733,
                                              OUT.
DIRECTION 5210, LEFT
380, ADD 400, DOWN
35, OVER.
                                              COMBAT OP IN OPEN,
                                              ICM IN EFFECT,
                                              AUTHENTICATE LIMA
                                              FOXTROT, OVER
I AUTHENTICATE
PAPA, OUT.

                            Message to Observer

                                              H, 1 ROUND, TARGET
                                              AA7742, OVER.
H, 1 ROUND, TARGET
AA7742, OUT.

                            FIRE MISSION (POLAR)
                            Initial Fire Request

    Observer                                            FDC

Z56 THIS IS Z31, FIRE
FOR EFFECT, POLAR,
OVER.
                                              THIS IS Z56, FIRE FOR
                                              EFFECT, POLAR, OUT.

DIRECTION 4520,
DISTANCE 2300,
DOWN 35, OVER.
                                              DIRECTION 4520,
                                              DISTANCE 2300,
                                              DOWN 35, OUT.
INFANTRY COMPANY
IN OPEN, ICM, OVER.
                                              INFANTRY COMPANY
                                              IN OPEN, ICM,
                                              AUTHENTICATE TANGO
                                              FOXTROT, OVER.
I AUTHENTICATE 
ECHO, OUT.

                          Message to Observer

                                              Y, VT, 3 ROUNDS,
                                              TARGET AF2036, OVER.
Y, VT, 3 ROUNDS,
TARGET AF2036, OUT.

                        FIRE MISSION (SUPPRESSION)

    Observer                                         FDC

H18 THIS IS H24
SUPPRESS AB3104
OVER.
                                              THIS IS H18, SUPPRESS
                                              AB3104, AUTHENTICATE
                                              DELTA JULIET, OVER.
I AUTHENTICATE
DELTA, OUT.

                    FIRE MISSION (IMMEDIATE SUPPRESSION)

    Observer                                          FDC

H18 THIS IS H24,
IMMEDIATE
SUPPRESSION
GRID 211432
AUTHENTICATION IS
TANGO UNIFORM
OVER.
                                              THIS IS H18, IMMEDIATE
                                              SUPPRESSION,
                                              GRID 211432, OUT.