Fire Support Handbook

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The FM outlines our core skills, policies and guides to ensure every member stands ready for the mission ahead.

The call for fire (CFF) is the standardised method of requesting support from indirect fire assets.

A CFF consists of six elements done in three transmissions. Every transmission is read back verbatim, because error correction is paramount when it comes to the battlefield’s most devastating weapon orchestrated by words alone.

Only when an element readback is correct, the FO continues to the next. Otherwise, the transmission is redone in full until it is error-free.

Because of this, the CFF epitomises the ABC of comms: accuracy, brevity, clarity.

It handles all of this for you as long as you follow its structure: trust it, because it is enough.

First transmission

The first transmission includes the Warning Order, or WARNO. It clears the channel of all other traffic and signals that a Call for Fire is underway. 

This also removes the need to begin every subsequent transmission of the CFF with your call signs, because it is understood that this is a conversation between only two.

• (1) identification: “Hammer, this is Sierra…”

The Call for Fire is initiated like any other radio transmission with a verbal handshake. You first identify the addressee call sign, which is the FSC, and then identify yourself with your FO call sign.

• Ex.1: (2) warning order: “...adjust fire (a), polar (b), over.”
• Ex.2: (2) warning order: “...fire for effect (a), [ ] (b), over.”
• Ex.3: (2) warning order: “...adjust fire (a), shift A01 (b), over.”

The WARNO consists of (a) the type of mission, and (b) the method of target location. If (b) is ‘grid’, then it need not be said as the assumed default, see ex.2.

Note that the method of target location does not include actual target location data.

Second transmission

The second transmission only includes target location data. Once again this is for easier error handling, so that the fewest possible factors need to be corrected and therefore retransmitted in full at a time.

• Ex.1: (3) target location: “Direction 1300, distance 2300, over.”
• Ex.2: (3) target location: “Grid 1234 tack 5678, over.”
• Ex.3: (3) target location: “Direction 3140, left 160, add 100, down 50, over.”

Whenever possible, the grid method of target location is preferred.

Third transmission

The third and final transmission of the CFF describes what is engaged, how it is engaged and when. This is where the most information can be delivered at once, so overload on either side of the transaction is most likely to happen here. Speak slowly, clearly, and follow the format of the CFF to set and fulfil correct expectations.

Also, try to include only what is strictly necessary for your CFF to achieve good effect. If you don’t need a target shape, leave it out. If you don’t need the time of flight or durations, don’t request them.

• (4) target description: “three infantry squads in the open, radius 100 …”

The target description as the only required element in the third transmission is chiefly present for the FSC to decide on ammunition and volume based on known factors. Infantry dug-in can be engaged differently to vehicles in the open, for example, and larger target areas require more volume to achieve sufficient effect.

• (5) method of engagement: “smoke in adjust, 5 smoke followed by 10 HE in effect, danger close …”

The method of engagement describes how the FO wants to engage the target, if not left to the FSC. This is also where the prowords DANGER CLOSE are stated, because it informs the FSC to double-check their solution, such as by cross-referencing friendly positions and movements.

• (6) method of control: “request time of flight, request splash, at my command, over.”

The method of control is defined by the observer to optimise the flow of the mission. When timing is important, the FO can request a control scheme to best suit their needs to ensure timely effect and good observation of the impacts.

The observer’s primary goal is to achieve first-round fire for effect. Especially with modern tools, this is a viable strategy, but can be achieved in myriad ways. Sometimes, environmental factors cause the impacts to miss, the FSC’s solution is wrong, or your target location is off. Knowing the distance to target is crucial in any case. 

In the absence of laser rangefinders and GPS precision tools, you can still correct range for adjustments using successive bracketing.

With bracketing, you are mathematically guaranteed to be on target upon conclusion. In fact, you can do this using only your eyeballs - no tools (or maths) required. However, it is time-consuming.

Setup

Ensure clear sightlines to your target such that you can see beyond and ahead of it.

Determine the target location as best you can using your preferred means and tools available. All methods of target location are valid for bracketing.

Begin a CFF using the ADJUST FIRE mission.

If DANGER CLOSE or to avoid collateral damage, request SMOKE IN ADJUST, HE IN EFFECT.

Include all necessary methods of control in your CFF such that you can observe the impacts: SPLASH is required.

Principle and Goal

The bracketing method works on geometric convergence: but don’t worry, you are involved in no maths.

When we first observe an impact, whether it is short of the target or behind it, we establish an initial bracket based on the observer-target distance, e.g., 400 metres when the OT distance is greater than 2000 metres.

This means: if the impact was behind it, we DROP 400. If it was in front of it, we ADD 400.

Our goal is to “break the 100-metre bracket” by overcorrecting to the other side of the target. We do this by continuously halving the correction with every subsequent adjustment and alternating ADD/DROP: when you first ADD, next you DROP, and vice versa.

This will alternate the impacts in front and behind the target.

Next, we ADD/DROP 200. Once again, it overcorrects, so if we were in front before, now we are behind and vice versa.

Now we DROP/ADD 100.

Breaking the 100-metre bracket

With this last adjustment, we have “broken” the 100-metre bracket and you will already observe impacts close to target.

The final adjustment from here is, “ADD/DROP 50, FIRE FOR EFFECT, over.”

Because we always halved the distance, we were mathematically guaranteed to converge on 0 error eventually. Whether we begin with 200, 400, 800 or 1600 metres does not matter – the bigger the bracket, the longer it takes, but it will always converge as long as we only ever halve the prior adjustment.

If you guess at any point, your error compounds with subsequent adjustments. In fact, the amount you guess is exactly the amount you move the final impact point forward or back from the target when you’ve finished halving.

Adjust lateral deviation

In principle, you can adjust for lateral deviation, i.e., LEFT or RIGHT, with the same method.

You can also “wait” with your lateral adjustments until you are nearly range-correct, only making gross deviation adjustments along the way.

At this point, you can use binoculars or compass to see the deviation in milliradians and convert it into metres, knowing the distance to your target, using the mil-relation formula.

Begin a CFF with the first transmission including the warning order, WARNO, in the following format:

[callsign of mortar/artillery battery], [callsign of FO], [type of mission], [method of target location, skipped if the method is GRID], over

The type of mission and method of location to choose from are:

As a second transmission, transmit the target location in on of the following formats, depending on the choice made when transmitting FM/BS-722 - Transmit a CFF warning order:

Start a third transmission and transmit the target description in the following format: 

[target type and number], 

[target protection], 

([target shape if not a point target])

Start a third transmission and transmit the method of engagement in the following format: 

([round choice + volume] in adjust), 

[round choice + volume] in effect, 

(danger close), 

([trajectory])

The format for the round choice + volume is:

([ammunition type of the round]) 

([number of rounds per gun] rounds), 

(followed by [round choice + volume])

Continue the third transmission and transmit the method of control in the following format: 

([time to fire]),

(continuous),

(duration, [duration in minutes]),

 ([rate of fire]),

(cannot observe),

(request time of flight),

(request splash)

Read back every transmission of the CFF verbatim after each individual transmission, replacing “over” with “out”

The MTO is the battery's confirmation of the FO’s CFF with their decisions: whether or not the target will be engaged at all, the final volume of fire and type of ammo used including all changes to the FO’s requests, the time of flight if requested, and crucially the target identification number.

The MTO is transmitted to the FO ahead of all shots. For expedience again, it is kept brief.

The first shot can ring out as soon as the FO has read back the MTO.

Suppression and immediate suppression missions do not require an MTO, because those missions are planned in advance.

Transmit the message to observer after finalizing how the request will be executed: 

([changes to the request]) 

[target number], 

over

The target number is decided by the battery director, in the following format: “[2 letters from AA → ZZ] [four numbers from 0001 → 9999]”

• Note down the target number assigned by the artillery battery
• Respond with the following, including an optional POSREP when needed:

[verbatim readback of MTO] 

(

break, 

[

[POSREP of the FO as 8-figure grid, for GRID/POLAR/ SHIFT FROM KNOWN POINT mission]

or

[direction from the FO to the target in milliradians, only for GRID missions]

]

),

out

Update observer on fire mission progress.

Confirm receipt of fire mission reports as they are sent:

• microDAGR settings
  • Click the top bar containing the current time
  • Click “Connect To”
• Main screen:
  • Upper half: your position
  • Lower half: sighted position
• Compass screen:
  • Bearing indicator of sighted target
• Target sighting:
  • Vector 21: scope in
  • Press Tab + R
  • Left: azimuth, right: slant range

See https://ace3.acemod.org/wiki/feature/microdagr for all MicroDAGR functionality

• Change settings from deg & SI to mrad & SI
  • 5x Tab for settings
  • R to cycle units: left: 6400, right: SI-U
  • 5x Tab to save
• Fall of shot function:
  • Short-press then press and hold Tab on target
  • Keep holding Tab until the end
  • Hit R on spotted impact, 1-P appears
  • Release Tab
  • Hit R with adjustments visible to cycle range/deviation and vertical shift
• A for Add, d for drop (note uppercase vs. lowercase)
• L for Left, r for right (ditto)
• Read from left to right for immediately transmittable one-round adjustment

See https://ace3.acemod.org/wiki/feature/vector for all Vector 21 functionality

Above: Vector 21 fall-of-shot function usage

Refine a fire mission based on spotted impacts in the following format:

[target number], 

(

(direction [direction from the FO to the target, in milliradians]), 

left/right [offset perpendicular to FO-target line, from the impact point to the target, in meters], 

add/drop [offset parallel to FO-target line, from the impact point to the target, in meters], 

(up/down [altitude change from the last provided value tto the target; altitude is measured above sea level]

), 

[type of mission],

over. 

Use the following prowords to control an ongoing CFF:

After judging the effect and further need of a fire mission, transmit an End of Mission, EOM, statement to conclude it, including any refinements as required, if recording as target is desired, and a summary of the effect from a BDA:

[target number], 

(

left/right [offset perpendicular to FO-target line, from the impact point to the target, in meters], 

add/drop [offset parallel to FO-target line, from the impact point to the target, in meters], 

(up/down [altitude change from the last provided value to the target; altitude is measured above sea level])

), 

(record as target), 

end of mission,

 [target BDA, see: FM/BS-799 - Provide a BDA], 

over.

Classify the effect of the used munitions on the target as one of the following categories:

Request a suppression fire mission in one transmission in contrast to the regular CFF procedure:

[callsign of mortar/artillery battery], [callsign of FO], [type of mission], [target location], over.

The correct readback of the transmission by the battery authorises the fire mission.

Clear communication between fire controllers and observers ensures accurate spotting and adjustment of rounds in flight. Standard cues provide consistent timing references for visual acquisition and correction:

These cues support accurate correction and enable timely battle damage assessment (BDA).

Use standard responses to confirm or clarify fire mission instructions then confirm readiness to fire or request further clarification if unsure.:

Release methods determine the timing and coordination of fire across multiple guns. Each method balances speed, control, and desired effects on the target:

Read back and comply with the release method given by the controller.

Give clear fire control commands during release phases, repeat commands as needed for safety or synchronization.

Clear status updates from gun crews allow fire controllers to track progress, synchronize timing, and manage ammunition effectively. 

Consistent use of brevity enables:

• Timely follow-up orders
• Safe fire stoppage if needed
• Effective BDA (Battle Damage Assessment) sequencing

See FM/BS-1149 - Communicate within a fire support element using the correct brevity for required prowords.

Use the correct brevity within a crew/section/battery to communicate effectively:

Fire support elements must remain flexible and safe to accommodate changing conditions or emerging hazards. Using safety controls ensures responsive and safe fire support delivery under pressure.

Issue safety control orders to stop or repeat a fire mission in a timely manner:

Comply with safety control orders issued by the commander. See FM/BS-1271 - Issue safety control orders

The Artillery Computer is a digital targeting aid. Its use is disabled by default in UNITAF operations to support manual calculation and realistic simulation.

• Authorised Use: Only permitted in operations classified as E4.
• Preconditions for Use:
  • Computer assistance must be available (via vehicle or facility). The following classes of vehicle are acceptable:
    • All self propelled guns (SPGs) and rocket artillery.
    • NATO/Western artillery guns (≥105mm) if a battery commander is present.
    • NATO/Western mortar carriers.
  • Plausible geolocation of gun and target must be possible.

Declaration Requirement: Enabling of the Artillery Computer must be stated in the mission OPORD.

• Choose level ground.
• Avoid terrain and natural features that may obstruct fire.
• Use available or potential cover.
• Maintain spacing between guns. 

• Orient the position for the desired fire direction.
• Allow enough space for movement and reloads. 

• Set the gun to the given azimuth and elevation.
• Load specified charge and ammunition type.

When not actively firing, fire support crews should prioritise the following in order:

1. Provide security and cover sectors.
2. Maintain or improve the gun position.
3. Inventory ammunition at each gun.
4. Inventory and restock ammunition
5. Assist in planning or calculating upcoming fire missions.

Three methods to specify a target:

• Grid: Grid coordinates from the map.
• Polar: Distance and direction from the observer.
• Shift: Offset from a known reference point, e.g. a TRP or PPT.

A fire mission typically follows this sequence:

1. Request: The observer sends a Call for Fire.
2. Acknowledge: Fire controller acknowledges and confirms received data.
3. Calculate: Fire controller determines and communicates firing parameters.
4. Lay: Crews apply the firing data and report when ready.
5. Release: The fire controller issues the fire order.
6. BDA: The observer conducts Battle Damage Assessment.
7. Adjust: Corrections are issued if required.

Steps 2 to 7 may be repeated until the desired effect on target is achieved.

Element leaders may delegate specific responsibilities to ensure efficient delivery of fire support.

Delegatable duties:

• CFF Communication: Receiving inbound Calls for Fire.
• Fire Mission Calculation: Determining charge, azimuth, elevation, and ammunition.
• Fire Mission Communication: Transmitting fire orders to subordinate elements.

• Determine gun location
  • Determine grid and altitude (ASL) of each firing point.
  • Use centre-point only if all guns are within 50m radius.
• Determine target location
  • Determine grid and altitude (ASL) via Grid, Polar, or Shift.
• Determine sight to target
  • Calculate azimuth, distance, and altitude difference.
• Develop the fire solution
  • Select charge using range table.
  • Determine base elevation; interpolate if needed.
  • Adjust for altitude difference.
  • Calculate time of flight.
• Set ammunition parameters
  • Set proximity/timed fuses based on altitude or time of flight if applicable.
• Verify all data
  • Recheck all data.
  • Ideally cross-check with a second calculator.

Fire missions are given by the Fire Controller in the following format : 

1. Gun/Section number
2. Target Reference Point or Pre-Planned Target
3. Release method
4. Type of round
5. Ammo information
6. Number of rounds
7. Charge
8. Azimuth
9. Elevation

1. Gun/Section number

2. Target Reference Point or Pre-Planned Target

Target number assigned during calculation, each fire mission has a unique target identification number.

See: FM/BS-802 - Establish target reference points (TRP) and FM/BS-803 - Establish pre-planned targets (PPT)

3. Release method

See: FM/BS-1147 - Execute fire release methods

4. Type of round

Type of ammunition to be used

5. Ammo information

Used for special rounds where a setting is to be configured (i.e. laser code or timed explosion) 

6. Number of rounds

The number of rounds to be fired by each gun (i.e. an order of 5 rounds for 3 guns will result in a total of 15 rounds being fired)

7. Charge

Charge number to be used (please note some Pisces may show the charge as a name ('close', 'medium', 'far') instead of a number, in those cases treat the smallest one as 0 then following modes counting up 

8. Azimuth

Azimuth with a modifier for continuous fire. The azimuth is always given as a 4 digit number

9. Elevation

Elevation with a modifier for continuous fire. The elevation is always given as a 4 digit number

• Transmit all fire mission parameters clearly in the correct format. See FM/BG-1273 - Issuing a fire mission to crews
• Repeat parameters when requested.
• Issue further commands as necessary
• Comply with the release command given by the observer.

Map tools can be used to more accurately determine 8 figure grid references. To do so, follow the procedure:

1. Deploy the map tool and align it to North.
2. Place the 0 mark of the grid tool on the target point.
3. Read the 4th digit of the easting from the left ruler.
4. Read the 4th digit of the northing from the bottom ruler.
5. Append both digits to the 6-digit grid.

The grid can now be transmitted using the FM/BS-477 - Read an eight-figure grid reference.

Use map tools to get a grid reference accurate to 10metres.

Map tools can be used to more accurately determine azimuth and distance. To do so, follow the procedure:

1. Deploy the appropriate map tool.
2. Move the centre dot to the first point.
3. Rotate the tool to align the lead line with the second point.
4. Read the azimuth in degrees or mils.
5. Align the 0 mark of the ruler with the first point.
6. Measure the distance in meters to the second point.

You now have an accurate azimuth and distance.

Use map tools to get an accurate azimuth and distance to a target.

A plotting board can be used to more accurately determine azimuth and distance. To do so, follow the procedure:

1. Centre the plotting board on the origin point.
2. Rotate the base board or ruler to intersect the target point.
3. Read the azimuth using the Vernier scale.
4. Measure the distance using the plotting grid.
5. If the target is over 3km away, use the lower-left origin.

You now have an accurate azimuth and distance.

Use a plotting board to get an accurate azimuth and distance to a target.

Fire support elements follow a three-tier hierarchy to enable scalable and organized delivery of indirect fire.

• Battery: Coordinates up to three Sections; highest level of fire support control.
• Section: Controls two to three Gun Teams; operates semi-independently within the Battery.
• Gun Team: Operates a single mortar or artillery piece; composed of a Gunner and Assistant.

This structure supports scaling from squad-level support to full Batteries. The highest level of commander present takes command, Battery -> Section -> Gunner.

Pre-planning fire missions during the mission design or briefing phase helps ensure that indirect fire support can be delivered rapidly and accurately once operations are underway. It also enhances coordination with manoeuvre elements by reducing the time needed to identify, communicate, and engage targets.

Common components of fire mission pre-planning include:

• Pre-Planned Targets (PPT): Plotting likely enemy positions, chokepoints, or objectives ahead of time allows for quicker engagement during execution. These targets should be labelled using standard MTO formats (see FM/BS-726) to streamline communication and avoid confusion.
• Target Reference Points (TRPs): TRPs serve as shared map references that observers and gun crews can use to orient fire missions. They are typically placed on prominent terrain features and labelled in accordance with FM/BS-802. This practice simplifies communication and improves accuracy, particularly for on-call missions.
• Fire Support Standards: Establishing default parameters for suppression, smoke, and general-purpose fire missions ensures consistency and saves time under pressure. These may include:
  • Rounds, volume, and rate for Immediate Suppression
  • Rounds, volume, and rate for Immediate Smoke
  • Preferred munition types and location methods FM/BS-804 - Set standard fire-support parameters
• Fire Mission Types:
  • Pre-Planned: Coordinated before the operation and often linked to a PPT or TRP. Enables faster delivery due to known parameters.
  • On-Call: Requested dynamically during the mission. Often relies on TRPs or observer data to establish target locations quickly.

Pre-planning these elements helps ensure fire support is available when and where it’s needed, without delaying the momentum of the operation.

Plot target reference points, TRP, on prominent map and terrain features for the purposes of shared known points.

Label TRPs in the format "TRP [group identifier] [number 01–10]", where the distinct group identifier broadly summarises an area of operations, phase, or cardinal direction relative to friendly positions or movements. 

Examples: “TRP N01” or “TRP SE03”.

Plot pre-planned targets, PPT, on likely targets to facilitate fast FM/BS-729 - Request IDF supression.

Label the PPTs with the same format as specified in FM/BS-726 - Transmit a message to observer (MTO).

Set the following parameters prior to mission start:

• Rounds used, volume and rate of fire for a IMMEDIATE SUPPRESSION mission
• Rounds used, volume and rate of fire for a IMMEDIATE SMOKE mission
• Rounds used, volume and rate of fire for a SUPPRESSION mission
• Preferred method used for target location