Standard words and phrases: what ROGER, WILCO and AFFIRM mean
Standard phraseology is a vocabulary test with one rule: each word has one meaning. The exam describes the meaning and asks for the word, or the other way round. Here are the sixteen words with the meanings as ICAO gives them, and then the pairs that get swapped.
The words
| Word or phrase | Meaning |
|---|---|
| ACKNOWLEDGE | Let me know that you have received and understood this message |
| AFFIRM | Yes |
| APPROVED | Permission for the proposed action granted |
| CHECK | Examine a system or procedure (no answer is normally expected) |
| CONFIRM | I request verification of (clearance, instruction, action, information) |
| CORRECTION | An error has been made in this transmission; the correct version is … |
| DISREGARD | Ignore |
| I SAY AGAIN | I repeat for clarity or emphasis |
| MONITOR | Listen out on (frequency) |
| READ BACK | Repeat all, or the specified part, of this message back to me exactly as received |
| ROGER | I have received all of your last transmission |
| SAY AGAIN | Repeat all, or the following part, of your last transmission |
| SPEAK SLOWER | Reduce your rate of speech |
| STANDBY | Wait and I will call you |
| UNABLE | I cannot comply with your request, instruction or clearance |
| WILCO | I understand your message and will comply with it |
Source: ICAO Annex 10 Volume II, 5.2.1.5.9, and Doc 9432.
The pairs that get swapped
- ROGER or WILCO. ROGER only says that you received the message. WILCO says that you understood it and will do it. A clearance or an instruction needs a readback or WILCO, not just ROGER.
- ACKNOWLEDGE or CONFIRM. ACKNOWLEDGE asks the other station to say that it received and understood. CONFIRM asks the other station to verify something, for example a clearance.
- READ BACK or SAY AGAIN. READ BACK asks for the message to be repeated exactly as received. SAY AGAIN asks the other station to repeat its transmission because you did not hear it.
- I SAY AGAIN or SAY AGAIN. It is the speaker who says I SAY AGAIN (for clarity), and the listener who says SAY AGAIN (please repeat).
- CHECK or CONFIRM. CHECK is an instruction to examine a system and is not normally answered. CONFIRM asks for verification and is answered.
- DISREGARD or CORRECTION. DISREGARD tells the listener to ignore the message. CORRECTION replaces an error in the message with the right version.
Saying yes, and saying you cannot
For yes the standard word is AFFIRM. “Yes” and “affirmative” are not the standard word. Use it when you answer a question or confirm a statement, and use UNABLE when you cannot comply with a request, an instruction or a clearance.
Where students lose marks
- Thinking ROGER means yes. It does not answer a question and it does not accept an instruction.
- Mixing up the “say again” family. The three look alike. Learn them by who is speaking.
- APPROVED means permission granted. It is the answer to a request and is not used for ordinary acknowledgement.
- STANDBY is not a refusal. It means wait, and the station will call you.
Study aid, not the regulation. National phraseology may add words; the AIP and your ATO’s manuals take precedence.
Quick answers
What does ROGER mean on the radio?
I have received all of your last transmission. It does not mean yes, and it does not mean that you will comply.
What is the difference between ROGER and WILCO?
ROGER confirms that you received the message. WILCO means that you understand it and will comply with it.
What do you say for yes?
AFFIRM. Not “affirmative” and not “yes”.
How do you ask someone to repeat a message?
SAY AGAIN. If you repeat for clarity or emphasis yourself, you say I SAY AGAIN.
Make it stick
Fly the Standard Words & Phrases drill: every item is a streak you have to land.