Phraseology

How to talk on the radio

What to say on the frequency, in which order — and how the calls differ between Europe, the US and VATSIM.

How a radio call works

Every call follows the same pattern. Learn it once — everything else on the frequency is a variation.

Start with who you are talking to: Delivery, Ground, Tower, Radar.

Your callsign. End every reply with it — that is how ATC knows you got the message.

On the ground your stand; in the air your position and altitude.

One clear request. If you listened to the ATIS, add its letter — “information Alpha”.

Words you'll hear

ROGER

“I heard you.” It does not mean yes — yes is AFFIRM.

WILCO

“Will comply” — you will do what was asked.

AFFIRM

Yes.

NEGATIVE

No. If your readback was wrong, it also introduces the correction.

STANDBY

Wait. Do not reply — ATC is busy, not ignoring you.

SAY AGAIN

“Please repeat.” Always better than guessing.

UNABLE

I cannot do that. Say why, or what you can do instead.

CORRECTION

I said something wrong — here is the correct version.

READBACK

Repeat the instruction back: levels, headings, speeds, squawks , altimeter settings, runway clearances.

BREAK

Separates two calls to different aircraft in one transmission.

MAYDAY ×3

Distress call — life-threatening. Said three times, it clears the frequency.

PAN PAN ×3

Urgency call — serious, but not immediately life-threatening.

Numbers on the radio

TREE for 3, FIFE for 5, NINER for 9 — so “nine” cannot be confused with the German “nein”.

ICAO says DECIMAL (“119 decimal 7”), FAA says POINT (“119 point 7”).

Flight levels in words: “flight level three five zero”. Squawk codes one digit at a time: “squawk two zero zero one”.

Big aircraft add a suffix to the callsign: HEAVY or SUPER.

A full IFR flight, call by call

DLH3FU from Munich to Bergen — the same flight as in the OFP Explorer. Every call from clearance to taxi-in.

ICAO vs FAA — same language, different habits

Topic	ICAO / Europe	FAA / US
Level changes	“climb / descend TO level …”	“climb / descend AND MAINTAIN …”
Decimal point	“one one niner DECIMAL seven”	“one one niner POINT seven”
Altimeter	QNH in hectopascal — “QNH 1013”	altimeter in inches — “29.92”
Transition	transition altitude varies by country (~5000–6000 ft)	fixed: 18,000 ft everywhere
Runway edge	“holding point”	“hold short of” — mandatory readback
Back on the runway	“backtrack”	“taxi back” / “back-taxi”
Pattern work	“circuit”	“traffic pattern”
Apron area	“apron”	“ramp”
IFR clearance	“cleared to (dest) via (SID), initial level, squawk”	CRAFT: Cleared to · Route · Altitude (climb via SID) · Frequency · Transponder
Callsign	full callsign, always	shortened form allowed once established
Speed release	“no ATC speed restriction” (varies by country)	“resume normal speed”

When it isn't standard

Real radio is not always the textbook flow. These calls all have a defined shape — and most of them have a trap.

“DLH3FU, BEHIND landing traffic on short final, line up runway 08R BEHIND.”
Conditional clearance: the condition comes first and last. Read it back WITH the condition — “behind the landing traffic, lining up behind, DLH3FU” — and only if you actually see that traffic. Never applies to a takeoff or landing clearance.
“DLH3FU, expedite descent.” / “expedite vacating.”
Do it without delay — faster descent, quicker off the runway. Not an emergency, just urgency.
“DLH3FU, are you ready for immediate takeoff?”
Someone is right behind you on final. Only say yes if you can roll the moment you line up — “negative” is always a valid answer.
“DLH3FU, go around, I say again, go around.”
Tower-initiated go-around: runway blocked, separation gone. Climb away and fly the published missed approach unless told otherwise.
“DLH3FU, traffic 2 o’clock, 5 miles, opposite direction, 1000 feet below.”
Traffic information — reply “traffic in sight”, “looking”, or “negative contact”. Saying it does not clear you to maneuver.
“DLH3FU, hold at LASGA as published, expect further clearance at 45.”
EFC — expect further clearance: the time you should expect to leave the hold. In Europe also: slot times — “call for start-up”, “your slot is 35”.
“DLH3FU, say level.” / “confirm level.”
A level check — often a hint you busted an altitude or are about to. Answer with what the altimeter shows.
“All stations, check stuck microphone.”
Someone is blocking the frequency. If it is you: on VATSIM check your PTT key — your client shows a stuck transmit light.
“Caution, similar callsign on frequency.”
Another DLH-something is on the same frequency. Listen extra carefully for your own callsign — call sign confusion causes real runway events.

“Unable.” / “Unable — request direct LASGA.”
You can always decline. Best with a reason or an alternative — ATC will rework it.
“DLH3FU, going around.”
Your own go-around needs no clearance — announce it, fly the missed approach, ATC picks you up from there.
“DLH3FU, TCAS RA.”
Your collision system issued a climb/descent command. Report it, follow the RA even against a clearance — ATC stops separating until you report “CLEAR OF CONFLICT, (clearance) RESUMED”. A contradictory instruction gets “ UNABLE , TCAS RA”.
“DLH3FU, minimum fuel.”
Committed to this airport, no more delay acceptable. NOT an emergency and no priority — but the step before one. Landing below final reserve is the next level:
“MAYDAY, MAYDAY, MAYDAY, DLH3FU, fuel.”
Fuel emergency: you will land below final reserve. Full priority. MAYDAY content: who you call, who you are, what is wrong, position/level, what you want, souls and fuel on board.
“PAN PAN, PAN PAN, PAN PAN, DLH3FU …”
Urgency — serious but not life-threatening (medical issue, single engine on a twin). Below MAYDAY, above normal traffic.
Squawk 7600 — “transmitting blind.”
Radio failure: set 7600 and, if only your transmitter works, broadcast “transmitting blind” plus your intentions. The other codes: 7700 emergency, 7500 unlawful interference. Guard is 121.5.
“DLH3FU, request left deviation 20 miles for weather.”
You do not have to fly into a cell — ask to deviate. If urgent: state your action, then ask.
“Say again.” / “Standby.”
You may ask for a repeat — and you may ask ATC to wait while you deal with the aircraft first.

“DLH3FU, please contact me.” — or a private message
A controller or supervisor wants a word — usually harmless: wrong frequency, a filed-plan issue. Follow the prompt.
“DLH3FU, radar services terminated, monitor UNICOM 122.8.”
The controller logged off mid-flight. Self-announce on UNICOM until the next sector is staffed — then check in fresh: callsign, position, altitude.
Your callsign tagged /t/ or /r/
Text-only or receive-only flags. Voice is the default and the preference — but text pilots exist and controllers will work them.
Silence after your call.
Either you stepped on someone, or your transmit did not key. Wait a few seconds, check the TX light, call again — then text.
Event traffic: clearance by private message.
During busy events, clearances and slot times may come via text or CPDLC . Read them back in text — the rules do not change.

VATSIM specifics

Callsign order: theirs first, yours last — “Munich Delivery, DLH3FU …” opens, “… DLH3FU” closes every reply.
Say the ATIS letter on first contact (“information Alpha”) — get it from the ATIS frequency or the controller info in the pilot client.
Voice is preferred but text is allowed: tag your callsign /t/ (text only) or /r/ (receive only). Text costs controllers more work, so keep it short.
Nobody online? UNICOM 122.800 — announce position and intentions like on a real CTAF : “Munich traffic, DLH3FU on final 08R, Munich traffic.”
Entering an online sector without a handoff: check in with callsign, position and altitude; on approach add the ATIS letter.
Controllers are volunteers and used to beginners — “say again” and plain language beat a guessed readback every time.
On busy events your clearance may arrive as text via CPDLC or a private message — the readback rules are the same.

1 SayIntentions Click-to-Talk — watch the correct call appear, click, listen. No pressure.
2 SayIntentions voice or BeyondATC — say the calls yourself; nobody human hears the mistakes.
3 VATSIM at a quiet field — pick a small airport with one tower online. One controller, no queue.
4 A full VATSIM flight — clearance to taxi-in, same calls as the examples above.

Practicing offline

Click-to-Talk puts the right call on screen and sends it for you — you see the correct wording while you learn.
Understands you even without standard phraseology — “pilot talk” works.
Checks readbacks, but forgiving by default; a stricter mode exists in the settings.
Can hand off to and from VATSIM mid-flight — practice alone, switch to humans when ready.

Uses real FAA and ICAO wording — you hear and speak proper calls.
Push-to-talk voice recognition: you say the words out loud, like on VATSIM.
Handles regional details like squawk 1000 (Mode S) in parts of Europe.
The voices are AI, the procedures are not — readbacks follow real rules.

Standard phraseology is expected, but controllers are used to learners — say what you mean and they work with you.
Voice preferred; text works but is more work for the controller.
UNICOM 122.800 self-announcements whenever nobody is online.
Pilot ratings exist (P1 PPL through P4 ATPL, plus instructor/examiner levels) if you want your skills tested.

Standards: ICAO Doc 9432 — Manual of Radiotelephony & Annex 10, FAA AIM 4-2, FAA Pilot/Controller Glossary. Sim services: vatsim.net · beyondatc.net · sayintentions.ai — linked in the cards.