So you want to learn Air Traffic Control comms and get on the network? Could be Vatsim, could be IVAO… No matter, you gotta understand IFR Flight and ATC Communications then! This guide is made for Vatclass students from my IRL experience, so feel free to ask or add.
Airspaces in Vatsim (well, also in real life really) are divided into two major types : controlled and uncontrolled. The main difference here is that in uncontrolled airspaces you transmit blind, hoping that if there’s another traffic in the area, they would hear, and even more, respond to our transmission.
On the contrary, in controlled airspaces, you make requests, as there is a controller (or multiple controllers, in some high-traffic areas) that will assign where you’re going.
Basic ATC Comms Format
The basic format to follow is-
- Target, Who you are, Your message.
Note : the example airport, cities, and airlines used below is just an arbitrary example, it does not signify the exact phraseologies used in that region.
For example : Juanda Tower, Indonesia 1123, good morning.
When reading back transmissions it’s-
- Message, who you are.
Example :Taxi via taxiway A, B, and holding point A1, Delta 1123.
A common mistake that a lot of pilots make is not reading the callsign, and/or reading the callsign first before the message. DO NOT WORRY, the ATC is human too. No need to apologize either if your message is understood, just do better next time.
Common Traffic Advisory Frequency (CTAF)
In uncontrolled airspaces, we use a Common Traffic Advisory Frequency (CTAF), which is usually 122.800 MHz in Vatsim. This frequency, as the name suggests, is the common convention. However, at some airports the Advisory frequency is different, and you can take a look at the airport Chart (if there is one) or NOTAM, or any other source if there’s a specific frequency
CTAF Format
The format used in a CTAF frequency is basically:
- who you are
- Where you came from recently
- where you are now
- where you want to go
So for example:
Traffic advisory, PK-CAO departed Budiarto, climbing passing 3000 feet for 8000 feet, now 10 miles from IMU radial 210 inbound.
During my IRL flight training, my instructor told me to add “Any traffic in the area please be advised”. But after some discussion with other sim and IRL pilots, they told me that this is plain redundant. Because it’s implied.
See, we are following the format.
- Traffic advisory – the audience of your transmission. You can say “Denver traffic” if you’re still in Denver.
- PK-CAO being your airplane’s registration
- Departed Budiarto- Where you come from
- Climbing passing 3000 feet for 8000 feet – Where you are now
- 10 Miles from IMU VOR, radial 210, and is inbound. Meaning you’re on heading 030.
- Destination is Bandung – Where you are going. This gives an idea where your next heading could be.
So basically it’s announcing your location in 3d space where you want to go, and hopefully it creates a mental picture to any other traffic receiving the transmission.
In a traffic pattern, CTAF transmissions must be made in each of the legs (upwind, crosswind, downwind, base, and finals). You must also announce if it’s left/right crosswind, downwind, or base. Don’t be that guy that announces “left finals” or something.
Communications in a Controlled Airspace
In an airspace, there are usually several frequencies, which you can find on the top section of the chart (any type of chart):
ATIS (Automated Terminal Information Service)
ATIS (Automated Terminal Information Service) to get the weather. You will get a letter for this, for example “Jakarta Soekarno Hatta Information Charlie” then the weather (wx) info. Note the letter because you need to pass this info when announcing next.
Clearance Delivery (DEL)
Clearance Delivery is used to de-congest the GND frequency for initial flight plan clearance requests. Here you request the clearance to your flight plan (duh).
For example
“Juanda Delivery, Indonesia 1123 Heavy, request clearance with Charlie”
- Explanation : again, same format; target, origin, message.3
- Then the ATC will reply like, “Indonesia 1123 Heavy, cleared to Bali as filed, use MOVMO 1A Departure, climb 3000 feet initially”. The departure is the SID name, usually they will give you the appropriate SID to be used for the route you filed, as in it would be in the same general direction.
- “As filed” can only be used BY THE TOWER, not by us. It’s always assumed that we want to fly the filed flight plan.
- Then you READ IT BACK, using the readback format, “message, origin” no need to add target. For example, “Cleared to Denver as filed, Capital 1 Departure, 3000 feet initially, Singapore 1123”. Note that not every word is repeated, just the core message.
- Then the tower will acknowledge if you’re correct, or correct you if there’s a mistake, like “Indonesia 1123 Heavy, readback is correct, contact ground on 118.9 when ready to push”
- Then you readback, always. Now, the frequency here is important because for example, Jakarta has an 125.45 and 124.20 for Jakarta RADAR.
- DEL is not always available, usually GND will handle this.
- In Indonesia, the type and Person on Board is always requested by ATC, but apparently this is not the case in other parts of the world, mostly because it’s written in the flight plan.
Ground (GND)
If DEL is not available, you make your initial clearance request from here. Then you can request pushback and taxi when you’re ready. GND will also handle the taxi routing and clearances.
- Example : “Juanda ground, Indonesia 1123 heavy is at stand 17, request push and start”
- They will reply, “Indonesia 1123 heavy cleared for push and start, face West (just an example), report when ready to taxi, squawk 2107”.
- Then you contact the pushback truck for the pushback, and you start your engines.
- Then when you’re ready and the ground crew tells you that the bypass pin is removed (for retracting the landing gear) you can contact GND that you’re ready to taxi.
- Then GND will give you a taxi routing, and you read this back. There’s a HOLD SHORT of runway X at holding point Y, and you HAVE to follow this as to not disrupt the flow of incoming/departing traffic… Like the most recent one at Chicago Midway (Feb 2025)
- When taxiing, do NOT assume that everything will go well (as always) because GND can give you a STOP command if you’re conflicting with other aircraft; i.e.: collision, or head on.
- Then they will hand you over to the tower. If they don’t give you a frequency (they usually do) you can look in the chart. If there’s more than one frequency, confirm to GND which frequency to contact.
Tower (TWR)
Tower is for handling the initial airborne aircraft. Usually you get handed over to Tower when you’re approaching the holding point. If GND is not available, sometimes due to the traffic being too sparse (yes even IRL), TWR will handle GND too.
- Initial contact to the tower (from GND) is just like a phone call. “Juanda tower Indonesia 1123 heavy, good morning”
- Then they will tell you to either: “line up and wait” which is enter the runway, line up for departure, but do not depart just yet. Or “line up behind traffic” which is to wait for the landing traffic, after it lands, you can line up. That’s the basics, there are some more compound commands, but I don’t want to confuse you.
Departures (DEP)
As the name suggests, they handle the departures.
- When contacting APP and CTR, usually they already give you a squawk number; they might also ask you to “recycle squawk number” which means change it to the one they just said. When you make the initial contact, just say “Indonesia 1123 heavy, climbing passing F310 for F350”. Use flight levels when you’re above transition altitude, and altitude when you’re below transition level.
- Assuming you’re on Mode C (Altitude Reporting) they can already see your altitude, speed, and heading, right? BUT! You ALWAYS need to report your passing altitude and cleared altitude or flight level. The altitudes are required to verify your clearance and check that your displayed altitude data is correct. When following given speed restrictions these should also be reported to the ATC. Unless you are told to use “CALLSIGN ONLY”, these are required. – Thanks Paul from VATCLASS for the addition
- Sometimes when DEP is not available, APP will handle your departure.This is quite confusing. You’re departing but you’re being handled by approach? Yes, sometimes, when Approach handles the area right outside the tower’s jurisdiction. So it handles initial climb clearances and also approaches before/after handed off by the tower.
Center (CTR)
Center (CTR) : Center is sometimes called Radar, they handle the traffic right before/after APP, and has the most coverage. They handle the entire Flight Information Region (FIR).
Approach (APP)
Approach (APP) : Sometimes, when Approach handles the area right outside the tower’s jurisdiction. So it handles initial climb clearances and also approaches before/after handed off by the tower like DEP does.
When approaching, CTR will hand you off to APP, then to TWR, then to GND. DEL doesn’t have an equivalent for arrivals.
When you arrive at the gate, we’re supposed to close our flight plan by saying “Indonesia1123 heavy, shutting (down) and closing (flight plan), good day” or thanks, or whatever farewell you deem appropriate. However, after discussion with some controllers, they say that after we park, it is ASSUMED that we want to close the flight plan, so this is NOT necessary.
Tips When Starting Out
DO NOT WORRY. The people listening to your conversation is also human. The most important principle in communications is as long as your message is understood, then there’s no problem. If you make a mistake, say “CORRECTION” then say your corrected message / part of message.
Also, they’re humans after all. So they’d understand if you make a lot of mistakes starting out. We all gotta start somewhere…
And since we’re both humans, if you’re in doubt, ask them to “SAY AGAIN”, use plain English if required.
This guide is far from perfect, as it is written for Vatclass students with lots of assumptions. If there are confusing terms or maybe suggestions to edit some parts of the guide, comment below!
This article had been mentioned on https://www.reddit.com/r/VATSIM/comments/1iwpup8/wrote_a_basic_atc_comms_guide_yesterday/
