Radio Telephone Operator

Table of Contents

Advanced Radio Operation

Being able to quickly and effectively communicate with all of the assets in the field is the staple on which all Arma operations rely. Some missions may only have one or two assets, however, there will be times where you will need to efficiently communicate with 3 or more types of assets that may span distances well over a 5 kilometers. As such, the traditional handheld 152 radio will not cut it. Insert Long-Range backpacks.

Radios such as the AN/PRC-155, MR3000, and RT-1523G are wearable backpack radios designed specifically for RTO, JTAC and FO operators in mind. They work as a normal backpack with the added functionality of being able to communicate at distances at and beyond 20 km and are a vital part of the RTO/JTAC/FO kit.

For full certification documentation, please check out the full RTO Handbook.

Useful Terms

Within this list, we will briefly explain several terms that may be brought up later in this guide or referenced throughout training.

  • Callsign: The designation of an element on a radio net. A callsign may include multiple individuals in a group or a single user. All units that communicate over a radio net should have a callsign and be referred to by it whenever on the net.
  • Bottleneck: When an excess of callsigns are forced to communicate and coordinate efforts to/through a single callsign; this single callsign is a bottleneck.
  • Span of Control: The amount of callsigns a single individual can effectively communicate with. See Span of Control for more detail.
  • Radio Transmitter Operator [RTO]: A user assigned to handle various radio channels delegated to them by leadership. RTO’s are characterized by their role in relaying information to other units and coordinating logistic supply/insertions.
  • Forward Observer [FO]: Similar to an RTO, an FO is characterized by their specific role in planning and calling for artillery fire missions, and coordinating ground support assets like Armor.
  • Joint Terminal Attack Controller [JTAC]: Similar to an FO, a JTAC is characterized by their specific role in planning and calling for Close Air Support, and coordinating air assets like Rotary and Fixed Wing.
  • Fire Mission: Any call for ordinance to any asset, including but not limited to; Artillery, Fixed Wing and Rotary Wing.
  • Close Air Support [CAS]: A call for fire to be carried out by Fixed or Rotary Wing support assets.
  • Egress: The direction (in degrees) that an aircraft will be travelling after passing the target during a fire mission.

Setting Up Nets

At the beginning of an operation, each individual team/squad needs to have a callsign and a frequency assigned. There is a specific process for this to ensure continuity between units regardless of the mission type, faction or composition.

In this picture, we see the following force composition:

“Mesa Actual” [1] infantry squad, made up of two [2] teams:

Fire Team “Mesa One”

and Fire Team “Mesa Two”.

“Regent” an infantry recon team.

“Sierra” a Rotary-Wing asset.

“Axel” a Mortar asset.

Main net frequencies (squad level or support units) should be whole numbers. Subordinate units may use decimals for continuity and cohesiveness.

When choosing a callsign you should try to meet the following criteria:

  • One word/name, made up of 2-3 syllables.
  • Each syllable should be distinguishable for clarity.
  • The word/name used should be semi-serious.

Good Callsign Examples: Mesa, Regent, Adjutant, Sierra, Empire.

Bad Callsign Examples: Murmur, Unicorn, Slade, Abracadabra, Bow.

Designations can be added into an existing callsign to clarify what specific individual is being contacted, or making contact:

  • The leader within any callsign is referred to with the designation: “Actual”
  • Medics use the designation: “Mike”
  • RTO/JTAC/FO use the designation: “Romeo”

Advanced Grids

A typical six [6] digit grid provides accuracy within 100 meters, this is usually enough to guide a fire team to where it needs to be. For some fire missions, the intended spread of damage might even fit quite well into the 100 meter space. However, most fire missions require a greater level of accuracy, and therefore, radio operators must become familiar with eight [8] digit grids, which provide accuracy within 10 meters.

The image to the left shows a map tool being held up to a series of grids. The default map will only provide the numbers for the six [6] digit grid: 078 042

The map tool will make it easier to get a more precise eight [8] digit grid.

In this case, we are trying to get the eight [8] digit grid of the tower shown on the map. Place the cursor over it with the map tool in position, the red lines of the cursor then line up with the ticks on the map tool.

Grids are always read in the following order: Left to Right, then Bottom to Top. This is how we will count the ticks; from left to right 6, from bottom to top 2. Now we add these number to the existing six [6] digit grid and get the following grid: 0786 0412

Once you’ve understood this procedure, you should be able to estimate the additional ticks for an 8-digit grid without the need for a map tool. This will save time in the future.

Additional Channels

The most challenging part of being an RTO is actually handling the communications between so many assets, duh. Fortunately, TFAR makes it quite easy to navigate a multitude of different radio channels. Beyond the normal single channel that is bound to your Caps Lock (or Ctrl+Caps Lock) you also have the ability to set additional channels on all radios. By default these additional channels are bound to T and Y (for the long range) if you have them configured and they allow you to easily hear and communicate on up to 2 channels per radio at once.

In addition, all radios also have the ability to “Rapid Switch” between channels 1-8 on your radio. This allows you to set up all of the independent assets on their own radio frequency, and then quickly switch your Long Range to that frequency whenever communication is required.

To reduce confusion when listening to multiple channels, you can set which ear you listen to individual radios from (right/left/both), you can even set your alternate channel to a different ear as well. You can also set one radio to be louder than another, although this cannot be configured for individual channels.

It is highly recommended to mess around with the different radios to become familiar with them, and to practice using multiple channels, including your alternate as often as you can.

Span of Control

The amount of units one person can effectively control and coordinate by themselves is known as span of control. When determining your own span of control you should always consider worst case scenarios.

For example, you may have radio communications with five assets that don’t communicate very often during a mission. This may seem to be an acceptable setup at the beginning of the mission, however, should all five of those assets need to communicate with you at once, you probably wouldn’t be able to effectively manage your radio channels effectively. More importantly, if you are the only one who can assist or coordinate those assets, then a bottleneck has just been created. A bottleneck, for radio communications, is when vital information becomes held back or restricted because too many units must communicate to one, busy source.

You should avoid having more than three [3] total radio channels (two [2] is most ideal). Between those channels you should avoid having more than four [4] individual callsigns (other than yourself) assigned in total. If you know that you have trouble understanding or hearing other units over nets during hectic situations like fire fights, you should consider limiting yourself to even fewer total channels and callsigns. Additionally, you may have to consider adjusting your audio settings for both Arma 3 and Teamspeak 3.

Asset Coordination

Insertions & Extractions

Coordinating troop insertion and extraction will be the most common task assigned to an RTO during a mission. As such it is vital to understand the type of asset you are using, and work with the Pilot/Driver of the vehicle being used at that time. When planning and calling for an Insert/Extract, the RTO may have to pick an LZ (landing zone) appropriate for the asset being used. For this reason, it is important that an RTO understands the movement plan for ground troops, and the terrain in the area of operations. A bad LZ will often waste time, and can be dangerous for Rotary Assets.

Remember to plan ahead! Reinsertion coordination also falls under the duties of an RTO, this means planning LZs around the movement of friendly forces and giving consideration to enemy forces in the area. Without this planning, reinforcements may be stuck in the rear for an extended period of time.


Logistics are extremely important to sustaining forces in the field and can be a hassle for squad and team leaders to handle while in a combat zone. To help remove stress from command units and ensure ground forces stay in the fight, an RTO should pre-plan as much of the logistical process as possible before leaving base, and continue to acquire information on the supply needs of friendly forces as the fight goes on.

Resupply can come in many forms, and some are more appropriate for the situation. If an area is secure enough, a Rotary or Ground asset can be called into the area to drop off supply boxes. However, if the area is hot, Fixed and Rotary Wing assets can always airdrop containers in the vicinity of friendly forces.

Logistic crews have a lot of down time at the beginning of an operation, but almost none when things heat up; this is usually caused by emergency supply requests being stacked on top of insertions. To mitigate this issue, an RTO should always be updating logistical assets with a list of items to be prepared for drop. This way, logistic crews can pre-package the right supplies and have them ready much quicker. RTO’s can even take initiative and prepare logistic drops before the squad leader requests them; so when the time is right, the RTO only has to ask permission to make the call.

Attack Control

The “5-Lines”

1. Target Description

Define what type of target the asset will be firing at. This will help them make any necessary adjustments in adjusting their shot or spotting the target. A few useful definitions to use are as follows:

  • Infantry (You may specify if Team, Squad or Platoon)
  • Soft Vehicle (You may specify if MRAP or HIMARS)
  • Armor (You may specify if MBT, IFV, APC, MLRS or SPG)
  • Bunker/Installation

2. Target Location

Use a 6-digit grid if the strike is meant to be a large area of effect. Use an 8-digit grid for any target area smaller than 100 meters. You can add the additional information of any large or useful terrain features, such as; Hilltop, Valley, Radio Tower, Bridge, etc.

3. Marker Type (Aircraft or Laser Designated Only)

You may use Coded Lasers from Designators or Turrets to mark a target for locking on to, but this must be made very clear to the asset making the strike, as they may be better off without it. You may also mark a target for visual reference alone using markers such as:

  • IR Laser (PEQ-15 or other non-locking laser)
  • IR Strobe/Grenade
  • Colored Smoke (Red Preferred)

4. Ordinance Requested

This will depend on the asset you are calling for. If you don’t know what ordinance will be best suited for the target, you may simply tell the asset to use the best available ordinance so long as you have provided an adequate target description. Be sure to tell artillery assets how many rounds they should fire for the strike.

5. Egress (Aircraft Only)

This is the direction (in degrees) that the aircraft should be headed after they make their strike. This is to ensure any ordinance that overshoots or undershoots the target is less likely to hit nearby friendlies. Use an egress to maintain better fire control of the asset and mitigate the risk of fratricide.

Follow Up

JTAC and FO personnel should always observe the strike whenever possible. This way, they can ensure the target has been destroyed or see what adjustments will need to be made to confirm the destruction of the target.

For Aircraft

If the asset missed the target, inform them of the distance and direction the strike hit in relation to the target. There are two ways this can be accomplished:

  • If the egress is clearly defined and known, the JTAC can simply describe the previous strike as “Overshot”, “Short of Target”, “Left of Target”, or “Right of Target”, then give an estimate of how many meters. Example: “Overshot and Left of Target by 50 meters, how copy?”

This will allow the pilot to make a second pass on the target and take those adjustments into consideration.

  • Using degrees and meters, the JTAC can provide the distance and direction with the most accuracy and clarity regardless of the pilot’s intended approach.

For Artillery

After rounds have impacted the target, the FO should provide the distance and direction that the round impacted in relation to the target. This should be done using compass bearings and meters. Be sure to follow up as many times as needed, it may take several rounds to properly zero in on the target.

If the target has been hit but not destroyed, the operator should relay to the asset: “[Asset Callsign] you are on target, [negative/postive] effect on target.” Be sure to define whether the effect on target was Negative or Positive. If negative, this means the target seems completely unaffected by the ordinance provided, consider calling in something heavier. If positive, this means the target seems to be taking damage but is not entirely destroyed, request additional rounds or passes from the asset until the target is destroyed.

Once the target is destroyed, call in to the asset saying: “Target destroyed, fire mission complete, [Your callsign] out!”



Check on Learning: Trainees will be given a brief quiz over knowledge covered in training (all of which can be found in this guide).

  1. Define the roles of RTO, JTAC and FO, and the main differences between them.
  2. Explain the basic criteria for a callsign.
  3. Explain a bottleneck and how to avoid one.
  4. Explain the purpose of an Egress bearing.
  5. Recite the three main callsign designations.

Call for Fire: Trainees will be given a target 600 to 1200 meters away, and a support asset on a long range channel. Trainees must successfully call in a strike on the target.

  • Support asset may be Air or Artillery; trainees will be informed of the callsign, frequency and available ordinance of the asset prior to beginning the exercise.
  • Trainees will use an 8-digit grid for target location.
  • Ordinance will strike the grid given, but fire may be adjusted based on the information provided by the trainee:
    • For Artillery, the trainee can give additional info after a strike to zero in on the target until it is destroyed.
    • For Aircraft, the trainee can mark the target or provide additional location reference information to help guide the asset.

Once the test is complete and the instructor has determined that the trainee has performed adequately enough to fulfill the RTO/JTAC role in a live operation, they will officially be RTO/JTAC certified.

For full certification documentation, please check out the full RTO Handbook.