How Pilots Pronounce Numbers
Aviation uses modified number pronunciation to prevent confusion over radio. Here's the ICAO standard used by pilots and ATC worldwide.
| Number | Standard | Aviation |
|---|---|---|
| 0 | Zero | ZE-RO |
| 1 | One | WUN |
| 2 | Two | TOO |
| 3 | Three | TREE |
| 4 | Four | FOW-ER |
| 5 | Five | FIFE |
| 6 | Six | SIX |
| 7 | Seven | SEV-EN |
| 8 | Eight | AIT |
| 9 | Nine | NIN-ER |
| . | Point | DAY-SEE-MAL |
| 00 | Hundred | HUN-DRED |
| 000 | Thousand | TOU-SAND |
Why Different Pronunciations?
"Three" becomes "tree" to avoid confusion with "free." "Five" becomes "fife" so it can't be confused with "fire." "Nine" becomes "niner" to avoid the German word "nein" (no). These distinctions save lives when a pilot needs to read back an altitude or heading clearly through radio static on a frequency shared by speakers from dozens of countries.
Real-World Examples
Altitude 10,000 ft"Flight level wun ze-ro ze-ro"
Heading 270°"Heading too sev-en ze-ro"
Frequency 121.5 MHz"Wun too wun day-see-mal fife"
Runway 27L"Runway too sev-en left"
Squawk 7700"Squawk sev-en sev-en ze-ro ze-ro"
Altitude 3,500 ft"Tree tou-sand fife hun-dred"