CHAPTER 4

CALL FOR FIRE

This chapter implements STANAG 2934, Chapters 5 and 6; QSTAG 225; and QSTAG 246.

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:

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

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.

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.

EXAMPLES
The following are examples of observer identification and warning order

ADJUST FIRE MISSION

Grid method: A57 THIS IS A71, ADJUST FIRE, OVER.

FIRE-FOR-EFFECT MISSION

Polar plot method: A57 THIS IS A71, FIRE FOR EFFECT, S (battalion call sign is B6S13), POLAR, OVER.

Shift from a known point method: A57 THIS IS A71, FIRE FOR EFFECT, SHIFT KNOWN POINT 3, OVER.

SUPPRESSION MISSION

F28 THIS IS F72, SUPPRESS AA7749, OVER.

IMMEDIATE SUPPRESSION MISSION

F28 THIS IS F72, IMMEDIATE SUPPRESSION, GRID NK453215, 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.

NOTE: Direction is expressed to the nearest 10 mils.

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:

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.

NOTE: Laser data are sent to the nearest 1 mil and nearest 10 meters.

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:

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.

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:

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.)

NOTE: Ammunition standards may vary from unit to unit. The observer must learn these standards upon assignment to a unit.

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.

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.

EXAMPLE

The observer transmitted SHIFT KNOWN POINT 2, OVER, DIRECTION 4680 .... He immediately realizes that he should have sent DIRECTION 5680. He announces CORRECTION, DIRECTION 5680. After receiving the correct read back, he may continue to send the rest of the call for fire.

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.

EXAMPLE

The observer transmitted LEFT 200, ADD 400, UP 40, OVER. He then realizes that he should have sent DROP 400. To correct this element, he sends CORRECTION LEFT 200, DROP 400, UP 40, OVER. The observer must read back the entire subelement, because the LEFT 200 and UP 40 will be canceled if they are not included in the corrected transmission.

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.

EXAMPLE

Warning order: FIRE FOR EFFECT, B (battalion call sign), OVER.

Target location: TARGET AA7731 (or GRID NB432789, ALTITUDE 520), OVER.

Method of engagement: VT, 3 ROUNDS.

Method of control: TIME ON TARGET IS 10 MINUTES FROM...NOW, OVER.

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.

EXAMPLE

The battalion call sign is A8T36. Battery A is R6G36. Battery A will adjust, and battalion will fire for effect. The MTO would begin T, G.

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

EXAMPLE

The observer requested ICM in effect and the FDO decides to fire VT in effect. The MTO begins T, G, VT IN EFFECT.

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.

NOTE: Messages to observers for registrations are shown in TC 6-40.

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.

EXAMPLES
Transmission authentication for final protective fire would be FIRE THE FPF. AUTHENTICATION IS WHISKEY HOTEL, OVER.

Transmission authentication for immediate suppression would be T23 THIS IS T44, IMMEDIATE SUPPRESSION, GRID NK124321, AUTHENTICATION IS TANGO UNIFORM. OVER.

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.

NOTE: Direction is sent before or with the first subsequent correction.

                             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.

NOTE: Immediate suppression missions are normally fired by a two-gun section using two rounds of HE or VT. However, this procedure is addressed in individual unit SOP and may vary between units.



Section II

SHELL-FUZE COMBINATIONS

4-14. DESIRED EFFECTS

Once the observer has located a target, he must decide how he wants to attack the target to get maximum effect. A thorough knowledge of the ammunition available will allow a rapid selection of the correct type of shell and fuze to use against the target. If it is not specified by commander's guidance, the type of effect is the first decision the observer must make. He has three choices--destruction, neutralization, or suppression.

a. Destruction puts a target out of action permanently. Thirty percent or more casualties normally will render a unit combat-ineffective. Direct hits with HE or concrete-piercing (CP) shells are required to destroy hard materiel targets.

b. Neutralization knocks a target out of action temporarily. Ten percent or more casualties will neutralize a unit. Neutralization can be achieved by using any type of shell-fuze combination suitable for attacking a particular type of target. Neutralization does not require an extensive expenditure of ammunition and is the most practical type of mission.

c. Suppression of a target limits the ability of the enemy personnel in the target area to perform their jobs. Firing HE/VT or smoke creates apprehension and confuses the enemy. The effect of suppressive fires usually lasts only as long as the fires are continued. Suppression requires a low expenditure of ammunition; however, its inability to have lasting effect on a target makes it an unsuitable type of mission for most targets.

d. When deciding whether to use impact fuze action (produces ground bursts) or time fuze or proximity action (produces airbursts), the observer should consider the following:

e. See Appendix E for a discussion of munitions effects and examples of optimum shell-fuze combinations for particular targets.

4-15. SHELL HE AND FUZES

Shell HE is the shell most often used by the observer in adjustment. It can be used with impact, time, or proximity (VT) fuzes for various effects.

a. Shell HE, Fuze Quick. Shell HE, fuze quick bursts on impact. It is used against the following:

Shell HE, fuze quick loses its effect if troops are in trenches, on uneven ground, in frame buildings, or on earthworks.

b. Shell HE, Fuze Delay. A 0.05-second delay can be set on the quick fuze to allow either ricochet fire or penetration (Figure 4-2). If the observer is firing into dense woods, against light earthworks or buildings, or against unarmored vehicles, he should use fuze delay for penetration. If a very high charge is fired at a small angle of impact on a very hard surface, a ricochet may occur, which results in low airbursts.

Figure 4-2. FUZE DELAY

c. Shell HE, Fuze Time. Shell HE, fuze tirne bursts in the air at a given time along the trajectory. An airburst is shown in Figure 4-3. It is used against the following:

Fuze time must be adjusted to the proper height of burst unless the firing unit has corrections for nonstandard conditions computed. Therefore, consideration should be given to another shell-fuze combination if time is critical and airbursts are desired. Fuze time should never be used for high-angle missions.

Figure 4-3. FUZE TIME OR VT

d. Shell HE, Fuze Proximity. The VT (or proximity) fuze is a radio-activated fuze that detonates at a predetermined height of burst. A VT fuze provides the same effect as fuze time but does not have to be adjusted. It is an excellent fuze to fire with shell HE for surprise and unobserved fires. Also, it is very effective in high-angle fires. It should be used in missions conducted by an aerial observer when an airburst is desired. It is used against all targets that can be attacked with fuze time.

NOTE: The VT fuzes M513 and M514 should not be used in the rain or on targets that are on water, snow, or ice. The M532, M728, and M732 VT fuzes ate not sensitive to water, snow, ice, or rain and may be used. M728 and M732 VT fuzes function at approximately 7 meters HOB ald can easily be misspotted as graze bursts by inexperienced observers. (A 7-meter HOB looks like a fireball at ground level.) M513 and M514 fuzes function at approximately 20 meters HOB.

e. Shell HE, Fuze Concrete-Piercing. The CP fuzes are used with shell HE in all cannon weapon systems except the M110A2 against concrete structures or earth- and log-reinforced emplacements. There are two types of CP fuzes: nondelay (used primarily for spotting or for clearing rubble and shattering concrete) and delay (used to destroy the concrete target) (Figure 4-4).

NOTE: Current CP fuzes (M78 and M78A1) are not safety-certified for peacetime use but may be used in combat. This problem is expected to be eliminated with the future production of the MK399 fuze (for use in military operations on urbanized terrain [MOUT]).

Figure 4-4. FUZE CONCRETE-PIERCING

4-16. SHELL WHITE PHOSPHORUS

Shell white phosphorus (WP) has four uses: incendiary, marking, obscuring, and screening. It can be used to destroy the enemy's equipment or to limit his vision. It is used against the following:

Also, shell WP can be used as an aid in target location and navigation. It can be fired with fuze time to obtain an airburst.

EXAMPLE
The following is an example of a WP call for fire: Z57 THIS IS Z18, ADJUST FIRE OVER. MARK CENTER OF SECTOR, OVER. WP 200 METERS HOB, OVER.

4-17. SHELL SMOKE

Shell smoke is a base-ejection projectile that is filled with canisters containing smoke. It is more effective than WP as a screening agent, because it lasts longer and has less tendency to pillar. The direction of the wind must be considered in the use of any smoke shell (WP or hexachloroethane [HC]). Further employment considerations are in Chapter 6, Section IV.

4-18. SHELL ILLUMINATING

The illuminating shell is a base-ejection projectile containing a flare attached to a parachute. Normally, it is used to illuminate areas of known or suspected enemy activity or to adjust artillery fire at night. Shell illuminating with a fuze setting for a graze burst may also be used to mark targets. Depending on the caliber, an illuminating shell can provide light for up to 2 minutes and can light an area of up to 1,000 meters in diameter. Further employment considerations are in Chapter 6, Section III.

4-19. SHELL FASCAM

a. The family of scatterable mines (FA.SCAM) includes shell FASCAM, which is fired by a 155-mm artillery weapon. It delivers antipersonnel or antitank mines against an enemy force to deny access to a particular area, to delay the attacking force, or to canalize them.

b. This all-weather, day-or-night mine emplacement system can be used in offensive, defensive, or retrograde operations. Antitank mines (remote antiarmor mine system [RAAMS]) are used to create antitank or antivehicle obstacles. Antipersonnel mines (area denial artillery munitions [ADAM]) are used in conjunction with antitank mines to create antitank obstacles difficult for dismounted personnel to breach.

c. Antipersonnel mines also can be used alone to create antipersonnel obstacles, to disrupt dismounted personnel operations, to restrict enemy use of terrain, and in counterfire.

d. All of these mines have a short or long self-destruct time depending on the type of shell fired to the target area. Further employment considerations are in Chapter 6, Section II.

4-20. SHELL COPPERHEAD

The cannon-launched guided projectile (CLGP) (Copperhead) is a high-explosive 155-mm projectile. It has a high hit probability on point targets, moving or stationary, and is extremely lethal. To use Copperhead, the observer must have a laser target designation capability and the proper pulse repetition frequency (PRF) setting. Also, he must be aware of the commander's Copperhead targeting priorities. Further employment considerations are in Chapter 6, Section V.

4-21. SHELLS ICM AND DPICM

For employment of ICM and dual-purpose ICM (DPICM), see Chapter 6, Section I.