Numbers
Definition
In aviation communication, numbers are pronounced using standard ICAO-approved phonetics to ensure clarity over radio transmissions. This prevents miscommunication due to noise, accents, or similar-sounding digits.
ICAO Standard Pronunciation of Digits
0Zero
1One
2Two
3Tri
4Four
5Five
6Six
7Seven
8Eight
9Niner
10One Zero
100One Hundred
150One Five Zero
1000One Thousand
1500One Five Hundred
How Numbers Are Spoken in Context
| Usage | Example | Say As |
|---|---|---|
| Altitude | 3,500 ft | “Three thousand five hundred” |
| Flight Level | FL90 | “Flight level niner zero” |
| Heading | 270° | “Heading two seven zero” |
| Frequency | 123.875 | “One two three decimal eight seven five” |
| Transponder Code | 7000 | “Squawk seven zero zero zero” |
| QNH | 1013 | “QNH one zero one three” |
Best Practices
- ✅ Say each digit individually unless otherwise standardized (e.g., thousands for altitudes)
- ✅ Use the word "decimal" when stating frequencies
- ✅ Speak clearly and at a steady pace
- ✅ Never abbreviate critical data like squawk codes or runway numbers
Incorrect vs. Correct Examples
| Incorrect | Correct |
|---|---|
| “Twenty-five hundred” | “Two thousand five hundred” |
| “Point eight seven five” | “Decimal eight seven five” |
| “Seven double oh oh” | “Seven zero zero zero” |