Why Do People Say Niner Instead of Nine​?

If you have ever spent a bit of time listening to aviation radio traffic, or even just clicked on a random clip out of curiosity, you might have noticed a moment where something sounds just a little off. A pilot saying niner instead of nine. It sticks in your head long enough to make you wonder why that is even a thing. And once you start noticing it, you usually see other things too, like numbers and words that sound almost familiar but not quite right.

That’s why you, as well as many people, often end up asking questions like:

• “Why do people say niner instead of nine?”
• “Why do pilots say niner instead of nine?”
• “Why do pilots say tree instead of three?”

Keep reading and discover the answers to all these questions!

If you’re interested in spelling alphabets, check out our NATO phonetic alphabet translator alongside our article “Spelling Alphabet: How to be Clear over the Radio?”.

So, why do people say niner instead of nine in the first place?

Well, basically, early radio and telephone systems were a bit rough — to learn more about them, check our article on the NATO Alphabet History. In short, limited bandwidth, interference, static, and unpredictable signal quality meant that short words were often the first things to disappear or get mangled. Numbers were especially exposed, because many of them are brief and differ only slightly in sound. Therefore, stretching “nine” into “niner” solves a fundamental problem.

There is also the international aspect to consider. Aviation communication is not limited to native English speakers, and some words have overlapping meanings across languages. “Nine”, for instance, sounds close to the German word “nein”, meaning “no”, which provides one more reason to extend the word and make it less likely to be misheard in a multilingual environment.

“Niner” isn’t the only strange-sounding number you’ll hear on the airwaves. “Why do pilots say tree instead of three?” is another question that often comes up. The answer follows the same logic: accents and audio distortion can flatten sounds, and the “th” sound is notoriously difficult to broadcast clearly over high-frequency radios.

When people ask why pilots say tree instead of three, they are often surprised to learn that the “th” sound doesn’t exist in many languages, making “tree” a more universally pronounceable alternative for international crews. That’s why you sometimes hear:

• “Tree” instead of “three”;
• “Fife” instead of “five”;
• “Fow-er” instead of “four”; and of course
• “Niner” instead of “nine”.

We hope we answered the question: “Why do people say niner instead of nine?” which is actually more about “Why do pilots say niner instead of nine?”. In any case, as you have seen, even with clearer digital radios and better modern equipment, the fundamental reason why people say niner instead of nine hasn’t changed much over the decades.