Close Air Support

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What is close air support?

Close Air Support (CAS) is the direct support of troops on the ground by air assets. It can be done by performed by both fixed wing aircraft and helicopters. Typically, there is an aircraft involved to deliver the weapons, and a controller to direct the fire. In general, the Master Arms CAS procedures are, while based on real life concepts, a bit simplified and streamlined. Most notably, we're currently focusing on one single way of doing it, namely the Keyhole, Type 2 procedure.

A controller is typically on the ground, and called a JTAC (Joint Terminal Attack Controller) or a FAC (Forward Air Controller). He can also be airborne, and is then called a FAC(A) (Forward Air Controller Airborne). For the sake of simplicity we will just refer to the controller as JTAC.

In real life, another key player is the ground commander, responsible for ground operations, but in our context it's not a role that is present, so you can disregard from that.

Flow overview

  • CAS Request - The JTAC contacts the commander requesting Close Air Support.
  • Initial contact - The CAS flight contacts the JTAC and gets some initial information.
  • CAS Check-in - The CAS flight provides the JTAC with its capabilities.
  • Situation Update - The JTAC provides some information to give the aircrew some SA.
  • Game plan - The JTAC provides broad term info for the upcoming attack.
  • CAS Brief
    • A) 9-line - The JTAC provides the necessary details for the attack in a standard format.
    • B) Remarks/Restrictions - The JTAC provides additional optional details.
  • Readback - The pilot reads back the mandatory info from the 9-line and the remarks/restrictions.
  • Correlation - The JTAC confirms that the pilot has acquired the correct target.
  • Attack - The pilot attacks the target.
  • Assessment - The JTAC provides an evaluation of the attack.
  • BDA - The JTAC (or the pilot) summarizes the final result of the CAS.

Flow details

CAS Request

The JTAC have identified a situation in which he needs air support. He contacts the commander to request an asset. In our context, this would typically be the AWACS controller. He should specify if he has any certain requirements when it comes to aircraft type, capabilities (sensors, weapons), play time and such. The commander will let the JTAC know if there's a flight available, provide the callsign for that flight and, if possible, an ETA when they will arrive. The commander will provide the CAS flight with the JTAC callsign, a frequency (or channel), and a location to go (can be a waypoint, a coordinate or some other instruction). This location is the contact point (CP).

Initial contact


When the flight is enroute to the contact point (CP), they will contact the JTAC letting them know they are on their way. In our case the JTAC will typically pass an Echo (target area) point to the flight. If the flight is not able to work with MGRS coordinates (which is standard), and need some other format (typically DD:MM:DEC coordinates), this should be mentioned before the echo point is communicated. The JTAC might also give the flight instructions to proceed to another location in relation to the echo point.

Note: The actual check-in has not happened yet. The JTAC typically wants to point the flight in the right direction before that, in order to save time.

CAS Check-in

The flight should not check-in until the JTAC asks them to. JTACs should be directive about when they want the aircraft to check-in, providing the details on the flight's capabilities. When the flight checks in, the following info should be included:

  1. Flight callsign
  2. Number and type of aircraft
  3. Position and altitude
  4. Ordnance (including laser codes)
  5. Playtime
  6. Relevant capabilities (typically if the aircraft is carrying targeting pod)
  7. Abort code (always "none" in our case)

Situation Update

The JTAC provides a short overview on what's happening, and if there is anything the flight needs to know, like any hazards (air defence threat, other CAS flights), enemy and friendly forces situation and artillery activity.

A) Game plan

The JTAC provides a short summary of how the attack is going to be performed. At the least, two items need to be communicated (and typically, this is enough):

  • Type of control - There is Type 1, Type 2 and Type 3 attacks.
  • Method - "Bomb on target" (BOT) or "Bomb on coordinate" (BOC). With BOT, the pilot will need to acquire the target visually or with a sensor. With BOC, this is not needed, but he will instead attack a certain location on the ground.

The game plan may include a requested ordnance type/number, but this is typically saved until the remarks section.

This section may also include other items regarding the target, the engagement, coordination and such. Sometimes, a short back-and-forth between the JTAC and the pilot is required.


The pilot writes this down. Typically in a printed CAS sheet. The CAS brief contains three parts:

A) 9-line

The 9-line is a standard format describing the attack details. The JTAC reads every line (some of them might be "not applicable", and are then explicitly communicated that way, with "N/A"). The lines are always read in a certain order and should be as short/to-the-point as possible. It's encouraged that the JTAC reads all the line headers ("Elevation", "Target" etc) out loud, to make it easier for less experienced pilots.

  1. IP (Initial point) - The starting point from which the aircraft approaches for the attack. In our Type 2 Keyhole procedure, it's a cardinal heading ("Alpha" for North, "Bravo" for East, "Charlie" for South, "Delta" for East) and a distance from the Echo (target) point.
  2. Heading - The magnetic heading from the IP to the target. Not used if there's no IP. (Not relevant during Keyhole procedure)
  3. Distance - The distance from the IP to the target. Not used if there's no IP. (Not relevant during Keyhole procedure)
  4. Elevation - The target altitude in feet MSL (above mean sea level).
  5. Target - A concise description, for instance "T-72 tank".
  6. Location - Typically just communicated as "by sensor talk-on", but can be communicated by grid position or lat/long if needed.
  7. Mark - The JTAC can mark the target with smoke, laser or IR. If laser is used, the laser code should also be provided.
  8. Friendlies - The distance (in meters) and cardinal/sub-cardinal ("North-west") direction from the target to the nearest friendlies.
  9. Egress - The cardinal/sub-cardinal direction for the pilot to egress after weapon employment.

The bold lines are mandatory for the pilot readback below.

B) Remarks/Restrictions

Remarks are additional info items to help the pilot. Typical remarks are:

  • Ordnance type/number (if not already specified in game plan).
  • Laser-to-target line - The direction of the laser (for instance "south to north").
  • Threats - AAA, manpads etc.
  • Weather - Cloud ceiling etc.
  • Friendly mark - If the friendlies have marked themselves with smoke or IR.

Restrictions are things that need to be followed, and always require readback. Typical restrictions are:

  • Final attack heading - If the attack needs to be performed at a certain heading (for instance "090 plus/minus 20").
  • Danger close - If the attack is expected to hit very close to friendlies (inside of the weapon's "0.1% probability of incapacitation" radius).
  • TOT - If there is a certain time-on-target when the weapons is intended to hit the target.


After the JTAC's CAS brief is finished, the pilot should read back the following things:

  • Line 4, 6 and 8 from the 9-line brief.
  • Any restrictions.

Note: Do not read back other lines, unless there's a good reason. Be concise.


The JTAC needs to make sure the pilot is acquiring the correct target. It can be done in many ways. Typically through a talk-on, guiding the pilot from a reference point, through distinguishable landmarks, to the target. This is a back-and-forth talk between the JTAC and the pilot, and can be very different depending on the situation.

Note: For talk-on, use "FIDO": From anchor, In a direction, Distance to travel, Object seen.


When the correlation has been completed, the JTAC clears the pilot to approach by asking him to "call when leaving IP". When the pilot has completed his preparations, and has turned towards the target, he calls "IP inbound", meaning he has left the IP and is inbound towards the target.

  • If the JTAC wants the pilot to continue, but he's not ready to let him open fire just yet, he calls "Continue".
  • When the pilot is 'ready to fire' he calls "In hot".
  • If the JTAC wants to cancel the attack, he calls "Abort, abort, abort!".
  • When the JTAC is confident everything looks good, he calls "Cleared hot!".

Note: For safety, "cleared hot!" are words ONLY to be said by the JTAC, ever. You are not allowed to asked "am I cleared hot". Just say "in", or "in, 4 miles" or such if you need to make the JTAC aware that your delivery window is closing.

When the pilot fires, he should preferably call out the weapon release. For instance "Pickle" (all bombs) or Rifle (air-to-ground missile, like a Maverick). No callout is needed for a strafe.

When the pilot has fired, he calls "Off" if he has fired, or "Off dry" if he didn't fire.

Laser considerations

If the pilot has released a laser guided weapon, and the JTAC should guide it, the pilot should call "laser on" when he wants the JTAC to start lasing.

  • For a Laser Maverick delivery, laser should be on before launch.
  • For a LGB drop, it's generally better to let the bomb fall for a while, building up energy before the laser is turned on, causing the bomb to maneuver.

When the JTAC is firing the laser, he acknowledges this by calling "lasing".


After the weapon has impacted, the JTAC should let the pilot know whether it was a hit or miss. Many times, a re-attack is needed. In this case, the JTAC simply asks for a re-attack. The instructions and restrictions from the first attack still apply, so no new CAS brief is needed. The JTAC may give additional instructions when the pilot is maneuvering, typically an target position adjustment. This is typically given with reference to where the previous attack hit ("from your hits, north 100").


When the JTAC no longer needs the CAS flight, or the CAS flight can no longer support (out of playtime i.e. low fuel, out of weapons, other reason), the CAS session ends. The pilot 'or' the JTAC could perform a BDA, but in our case typically the JTAC makes the BDA and communicates it to the pilot). At minimum, the BDA should say if the engagements were successful or not. Preferably, it should also include the size of the remaining enemy force, their activity (moving or digging in), and observed damage (typically number of destroyed vehicles).

Types of control

There are three different types of control. Currently, we only use Type 2. The other ones are listed here for future reference.

Type 1 (currently not used)

Type 1 is the most strict type, designed to minimize risk for hitting the wrong target. In this type, the JTAC is required to visually see both the target and the attacking aircraft.

Type 2

Type 2 control requires the JTAC to control individual attacks. For safety, the JTAC should attempt to visually acquire both the target and the attacking aircraft, but neither is required.

Type 3 (currently not used)

During Type 3, the JTAC clears the aircraft to engage targets in an area with multiple attacks. Just like in Type 2, he can, but doesn't have to, visually acquire the targets nor the attacking aircraft.


WIP In our example, a JTAC called Bowser5 has found a group of T-72 tanks that he needs to see destroyed. He has requested air support from his commander (in our case, the mission commander, or the AWACS) called Stingray. A flight of two F/A-18C Hornets called Arctic1 will be dispatched to the area where Bowser5 is operating. A contact point (CP) called "Eddie" has been setup over a known and clearly visible lake in the AO. This point is known by everybody in the coalition.

CAS Request

Bowser5: "Stingray, Bowser5"
Stingray: "Bowser5, Stingray"
Bowser5: "Requesting air support near CP Eddie"
Stingray5: "Copy. Standby."
Stingray5: "Arctic11, Stingray"
Arctic11: "Stingray, Arctic11."
Stingray: "Are you available for CAS tasking near CP Eddie?"
Arctic11: "Affirmative. Playtime 50 minutes."
Stingray: "Roger. Fly to CP Eddie. Contact Bowser5 on button 10."
Arctic11: "Arctic1, button 10, push."
Stingray: "Bowser5, two-ship F/A-18 Arctic1 is coming to you."

Initial contact

The flight Arctic1 is now enroute to CP Eddie, and has switched to Bowser5's frequency.

Arctic11: "Bowser5, Arctic11."
Bowser5: "Arctic11, Bowser5, advice when ready for echo point."
Arctic11: "Ready to copy."
Bowser5: "38 Tango, Lima November, 480 098. Elevation 2671. How copy?"
Arctic11: "38 Tango, Lima November, 480 098. Elevation 2671."
Bowser5: "Readback correct. Proceed to Bravo 10. Send your check-in."

CAS Check-in

Arctic11: "Bowser5, this is Arctic1, two-ship F/A-18 Charlie, at CP Eddie, angels 15. Carrying 500 20 mike mike, 2 GBU-12, 1 GBU-32 and 1 AMG-65E each aircraft. Laser codes: Arctic11 - 1511, Arctic12 - 1512. Playtime 40 minutes. Carrying ATFLIR. Abort code: none."

Situation Update

The JTAC provides a short overview on what's happening, and if there is anything the flight needs to know, like and hazards (air defenses, other CAS flights) or so. In our case, where we always use the Keyhole procedures, an Echo-point is always communicated (and read back) in this step.

Bowser5: "Situation update: Two enemy T-72 tanks located near a bridge. You are the only flight in the AO. Advice when ready for game plan."

Arctic1 flight now turns to Bravo 10 (meaning 10 nm east of Echo).

A) Game plan

Arctic11: "Ready for game plan"
Bowser5: "Type 2. Bomb on target. Advice when ready for 9-line."


B) 9-line

Arctic11: "Ready for 9-line."
Bowser5: (1) "IP: Bravo 10", (2-3) "Heading and Distance: N/A", (4) "Elevation: 1725 (One-seven-two-five)", (5) "Target: T-72 tank", (6) "Location: By sensor talk-on", (7) "Mark: None", (8) "Friendlies: 500 meters north", (9) "Egress: Left turn back to IP" *
Bowser5: "Advice when ready for remarks."
Arctic11: "Ready for remarks."

* Note: Line numbers are not read out loud

C) Remarks/Restrictions

Bowser5: "Requesting GBU-12. Self lase. Restrictions: Final attack heading 270, plus/minus 45."


Arctic11: "Elevation: 1725, Location: By sensor talk-on, Friendlies: 500 meters north. Final attack heading 270, plus/minus 45."
Bowser5: "Readback correct. Advice when ready for talk-on."
Arctic11: "Ready for talk-on."


Bowser5: "Do you see the bridge on the echo point?"
Arctic11: "Contact."
Bowser5: "Following the road west, 100 meters, do you see the small building?"
Arctic11: "Contact."
Bowser5: "Just to the south of that building, what do you see?"
Arctic11: "Capture T-72, facing west."
Bowser5: "That's your target. Advice when IP inbound."


Arctic11: "IP inbound."
Bowser5: "Continue."
Arctic11: "In hot."
Bowser5: "Cleared hot!"
Arctic11: "Pickle!"

The bomb hits the first tank and Arctic11 turns back to the IP.

Arctic11: "Off."


Bowser: "Impact! Target Destroyed. One tank left. Advice when ready for re-attack."

Arctic11 flies back to the IP, and starts looking for the other tank.

Arctic11: "Ready for re-attack."
Bowser: "9-line as before. Do you see another tank 70 meters west of the one you just hit?"
Arctic11: "Capture T-72, facing south."
Bowser5: "That's your target. Advice when IP inbound."
Arctic11: "IP inbound."
Bowser5: "Continue."
Arctic11: "In hot."
Bowser5: "Cleared hot!"
Arctic11: "Pickle!"

The bomb hits the other tank and Arctic11 turns back to the IP.

Bowser5: "Impact. Target destroyed."


Bowser5: "BDA as follows. Mission success. Two tanks destroyed. No other enemies. No further help needed. Thanks!"
Arctic11: "Copy, thanks, checking out!"

Arctic11 leaves the ROZ and goes back to the package channel.

Rotary wing CAS

For rotary wing (helicopter) CAS, the JTAC has two options:

  • Using the normal procedures as described above.
  • Using the more compact "5-line" format, effectively replacing the game plan and the CAS brief with this shorter format. The 5-line assumes the aircrew has good SA and gets a positive fix on the friendly forces. If the air crew fails to locate the friendly forces, the JTAC should not proceed but instead use a 9-line.

5-line application

The game plan and the CAS brief are replaced with the 5-line. All other sections remain unchanged.

  1. Warning order - This lets the aircrew know that this will be a 5-line instead of 9-line, as well as including the gameplan with control type and engagement method (typically Type 2 and Bomb on Target).
  2. Friendly location/mark - The position of the friendly observer (typically the JTAC himself). Should be communicated by talk-on from a reference point (like the echo point) and/or by marking with smoke.
  3. Target location - Typically communicated in relation to line 2 (friendlies).
  4. Target description/mark - A concise description, for instance "T-72 tank" and any mark (smoke, IR, laser including code).
  5. Remarks/restrictions - Optional remarks such as requested weapon, and any restrictions such as final attack heading (see remarks and restrictions above for details).

After a 5-line, only the restrictions should be read back.

5-line example

In this example, Orca6, a friendly Ka-50 is 5 nm east of Bowser5's (the JTAC's) position. The JTAC has enemy infantry 400 meter to the south. The echo point has already been communicated, and the check-in is complete.

Situation update

Bowser5: "Situation update: We are taking small arms and RPG fire from infantry to the south. You are the only flight in the AO. Advice when ready for 5-line"


Orca6: "Ready 5-line"
Bowser5: (1) "Orca6, Bowser5. 5-line. Type 2. Bomb on target." (2) "My position: next to building 100 meters north of echo point, marked with green smoke." (3) "Target location: Bearing 180 and range 400, marked with tracers." (4) "Description: Infantry in the open." (5) "Restrictions: Attack east to west. All effect south of echo point." *
Orca6: "Copy, will attack from east to west. All effects south of echo point."

* Note: Line numbers are not read out loud.

From that point, everything works just like during a 9-line. "IP inbound", "Continue", "In hot", "Cleared hot!" etc.



  • Miller time Completion of A/S ordnance delivery. Generally used by the last striker in conjunction with a precoordinated egress plan.