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On Air · Radio toolkit
Learn the alphabet. Say the numbers. Keep the message clear.
Try it
Letters and digits are spoken one at a time. Spaces separate words.
26 letters. One shared alphabet.
Use a code word for each letter when spelling names, locations or call signs.
Alphabet reference: NATO phonetic alphabet, codes and signals (opens in a new tab). The standard spellings are Alfa and Juliett.
Say each digit clearly
These radiotelephony pronunciations help tell similar sounds apart. Practise each digit at a steady pace.
Try this call sign
CONTROL 309
Control TREE · ZERO · NINER
Pronunciation reference: UK CAA CAP 413, edition 24 (opens in a new tab). This is an aviation radiotelephony reference. Follow your organisation’s procedure for security operations.
A quick reference
Some radio networks use short numerical codes to communicate routine messages.
Ten-codes vary by organisation. Follow your site’s radio procedure, and use plain language if you’re unsure.
| Code | Meaning in this reference |
|---|---|
| 10-1 | Receiving poorly |
| 10-2 | Receiving well |
| 10-3 | Stop transmitting |
| 10-4 | OK, message received |
| 10-6 | Busy, stand by unless urgent |
| 10-7 | Out of service, leaving air |
| 10-8 | In service, subject to call |
| 10-9 | Repeat message |
| 10-20 | My location is… |
Source: ISED Canada RIC-18, Annex A (opens in a new tab). These examples come from the Canadian CB and General Radio Service.
Check your recall
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Practise the references on this page.
Save a copy for your next shift.
Ten modules covering radio equipment, clear communication and radio discipline.
Explore the courseTalk to the officers around you, raise an alert in one tap and start every shift with a brief from Alpha One.
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