Radio Phrases: Roger, Wilco & Co.
What the words used on aviation, military and emergency radio mean | Pronunciation | Quiz
50 phrases
| Phrase | Meaning | Category |
|---|---|---|
| Roger |
I have received all of your last transmission.
It does not mean “yes” or “I will comply”: never use it to answer a question that needs Affirm or Negative. It comes from the telegraph R for “received”, spoken “Roger” in World War II spelling alphabets. |
Standard procedure |
| Wilco |
Short for “will comply”: I understand your message and will comply with it.
It already includes Roger: “Roger Wilco” is redundant. |
Standard procedure |
| Affirm |
Yes.
ICAO phraseology uses “Affirm”; the military commonly say “Affirmative”. |
Standard procedure |
| Negative |
No; or: permission not granted, that is not correct, not capable.
|
Standard procedure |
| Say again |
Repeat all, or the following part, of your last transmission.
“Repeat” is avoided on the radio: in military use it is an order to fire again. |
Standard procedure |
| I say again |
I repeat for clarity or emphasis.
|
Standard procedure |
| Standby |
Wait and I will call you.
It is neither yes nor no: it only means “wait”. |
Standard procedure |
| Unable |
I cannot comply with your request, instruction or clearance.
Usually followed by the reason. |
Standard procedure |
| Read back |
Repeat all, or the specified part, of this message back to me exactly as received.
|
Standard procedure |
| Correction |
An error has been made in this transmission; the correct version is…
|
Standard procedure |
| Disregard |
Ignore (the last transmission or instruction).
|
Standard procedure |
| Confirm |
I request verification of a clearance, instruction, action or information.
|
Standard procedure |
| Correct |
True, accurate.
|
Standard procedure |
| Acknowledge |
Let me know that you have received and understood this message.
|
Standard procedure |
| Break |
Indicates the separation between portions of a message.
|
Standard procedure |
| Break break |
Separates messages to different stations on a very busy frequency.
|
Standard procedure |
| Go ahead |
Proceed with your message.
|
Standard procedure |
| How do you read |
What is the readability of my transmission? (on a scale of 1 to 5)
|
Standard procedure |
| Over |
My transmission is ended and I expect a response from you.
Normally omitted in VHF aviation communications. |
Standard procedure |
| Out |
This exchange of transmissions is ended and no response is expected.
|
Standard procedure |
| Words twice |
Communication is difficult: send (or I will send) every word twice.
|
Standard procedure |
| Speak slower |
Reduce your rate of speech.
|
Standard procedure |
| Monitor |
Listen out on the frequency given.
|
Standard procedure |
| Contact |
Establish radio contact with the station given.
|
Standard procedure |
| Cleared |
Authorised to proceed under the conditions specified.
|
Standard procedure |
| Approved |
Permission for the proposed action granted.
|
Standard procedure |
| Squawk |
Set the transponder to the code given (e.g. “squawk 7000”).
|
Standard procedure |
| Loud and clear |
I hear you loud and clear.
|
Standard procedure |
| Mayday |
Distress call: grave and imminent danger, immediate assistance required. Said three times.
From the French “(venez) m’aider”, “come and help me”. A false Mayday is a crime in many countries. |
Emergency |
| Pan-pan |
Urgency call: a condition concerning the safety of a vessel, aircraft or person, but no immediate assistance required. Said three times.
From the French “panne”, breakdown. |
Emergency |
| Sécurité |
Safety message: important navigational or weather warnings. Said three times.
Mainly used at sea; pronounced “say-cure-ee-tay”. |
Emergency |
| Mayday relay |
A station relays the distress call of another that cannot do so.
|
Emergency |
| Seelonce Mayday |
Radio silence imposed by the station controlling distress traffic.
Maritime; from the French “silence”. |
Emergency |
| Seelonce feenee |
End of radio silence: normal use of the frequency may resume.
Maritime; from the French “silence fini”. |
Emergency |
| I spell |
I shall spell the next word phonetically.
|
Military |
| Figures |
Numerals follow.
|
Military |
| Wait |
I must pause for a few seconds.
|
Military |
| Wait out |
I must pause for longer than a few seconds; I will call you back.
|
Military |
| Radio check |
What is my signal strength and readability?
Answered e.g. with “loud and clear” or on the 1 to 5 scale. |
Military |
| Affirmative |
Yes (military and common use).
Civil aviation prefers “Affirm”, which cannot be confused with “Negative”. |
Military |
| Bingo |
Fuel state at which the return to base must begin (“bingo fuel”).
|
Military |
| Tally |
I have the target or non-friendly aircraft in sight.
Military aviation brevity code. |
Military |
| No joy |
I do not have visual contact with the target.
Military aviation brevity code. |
Military |
| Copy |
Received, understood.
Very common with the military, police and emergency services, but not part of ICAO phraseology, which uses Roger. |
Slang, non-standard |
| Roger that |
Informal variant of Roger: received.
The correct form is just “Roger”. |
Slang, non-standard |
| Over and out |
Film phrase used to end a conversation.
It is contradictory: “over” asks for a reply, “out” means none is expected. Just say “Out”. |
Slang, non-standard |
| Five by five |
Signal strong and perfectly readable (5 out of 5 for strength and readability).
|
Slang, non-standard |
| 10-4 |
Acknowledged, in the “ten-codes” of CB radio and some US police forces.
Not used in NATO or aviation phraseology. |
Slang, non-standard |
| Charlie Mike |
US military slang: “continue mission”.
|
Slang, non-standard |
| Oscar Mike |
US military slang: “on the move”.
|
Slang, non-standard |
No phrases found.
How well do you know radio phrases?
Score: 0/0
Streak: 0
Best: 0
Readability scale
Used to answer “How do you read?” or “Radio check”: “read you five” means perfectly readable.
| 1 | Unreadable |
| 2 | Readable now and then |
| 3 | Readable but with difficulty |
| 4 | Readable |
| 5 | Perfectly readable |
Transponder codes to remember
| 7700 | Emergency |
| 7600 | Radio failure (lost communications) |
| 7500 | Unlawful interference (hijacking) |
| 7000 | VFR flight with no assigned code (Europe; 1200 in the US) |
A sample exchange with the tower
An imaginary taxi clearance: note the “say again”, the read back of the instruction and the “wilco”. After first contact the tower abbreviates the call sign to “India Charlie Delta”.
Pilot
Tower, India Alfa Bravo Charlie Delta, radio check.
Tower
India Alfa Bravo Charlie Delta, Tower, read you five.
Pilot
India Alfa Bravo Charlie Delta, request taxi.
Tower
India Charlie Delta, taxi to holding point runway two seven, QNH one zero one three.
Pilot
Say again QNH, India Charlie Delta.
Tower
QNH one zero one three.
Pilot
Taxi to holding point runway two seven, QNH one zero one three, India Charlie Delta.
Tower
India Charlie Delta, report ready for departure.
Pilot
Wilco, India Charlie Delta.
Why people talk like this on the radio
On the radio one person talks at a time, often through noise, and every second of transmission ties up the frequency for everyone. That is why a small set of standard words is used, with a precise meaning and easy to recognise even for non-native English speakers.
Aviation phraseology is defined by ICAO; military phraseology by the Allied radiotelephone procedures (ACP 125) adopted by NATO. Many words are shared; others, such as “Copy” or “Over and out”, are slang or film inventions.
Roger, Wilco and Copy: the differences
- Roger only says “received”: it does not confirm you will comply, and it is not a yes.
- Wilco (“will comply”) says “understood and will comply”: it already includes Roger.
- Affirm is the yes to use when answering a question.
- Copy is the informal equivalent of Roger, common with the military and emergency services but not an ICAO term.
Mayday, Pan-pan and Sécurité
Three priority levels, each said three times at the start of the call:
- Mayday – distress: grave and imminent danger.
- Pan-pan – urgency: there is a problem, but no immediate help is needed.
- Sécurité – safety: navigation or weather warnings, mostly at sea.
All three come from French, then the reference language of international communications. In aviation an emergency is also signalled with the transponder: 7700.
Letters, numbers and times
Call signs, codes and difficult words are spelled with the NATO phonetic alphabet: G-ABCD becomes “Golf Alfa Bravo Charlie Delta”. Numbers are said digit by digit with the ICAO pronunciation (tree, fife, niner).
Times are given in Zulu time (UTC) and military positions in MGRS coordinates.
Frequently asked questions
Roger means “I have received all of your last transmission”. It does not mean yes and does not mean you will comply: that is what Affirm and Wilco are for.
Roger only confirms the message was received. Wilco, short for “will comply”, confirms it was understood and will be carried out. That is why “Roger Wilco” is redundant.
Copy means “received, understood”. It is widely used by the military, police and emergency services, but standard aviation phraseology uses Roger.
Not properly: it comes from films. Over means “I have finished and expect a reply”, Out “I have finished and expect no reply”: together they contradict each other. To end, just say Out.
Mayday, said three times, is the distress call for grave and imminent danger. It comes from the French “venez m’aider”, “come and help me”.
That the signal is strong and perfectly readable: 5 out of 5 for both strength and readability. In ICAO phraseology the answer is “read you five”.
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