Radiotelephony Phraseology and Communications Procedures
Phraseology is marked strictly because ambiguity on the frequency is a safety defect. Expect items on standard words, digit pronunciation, readback requirements, position reporting and correct use of prefixes.
Standard words
- ROGER means I have received all your last transmission. WILCO means I will comply. AFFIRM and NEGATIVE answer questions. STANDBY, not wait. SAY AGAIN, I SAY AGAIN, CORRECTION, DISREGARD, WORDS TWICE.
- OVER and OUT are not used in normal ICAO radiotelephony; ending a transmission needs no special word.
- Spelling alphabet: Alfa, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu.
Numbers and readback
- Digits: ZE-RO, WUN, TOO, TREE, FOW-er, FIFE, SIX, SEV-en, AIT, NIN-er. Say DECIMAL for the point: ONE ONE EIGHT DECIMAL SEVEN.
- Flight levels are separate digits: FL 120 is ONE TWO ZERO. Headings are three digits: ZERO NINE ZERO.
- Read back ATC route clearances, conditional clearances, hold-short and runway instructions, take-off and landing clearances, SSR codes, altimeter settings, levels, headings, speeds and frequency changes. ROGER is not a readback.
Worked example. Speedbird 245, descend to flight level one two zero, report reaching. Correct response: Descend to flight level one two zero, report reaching, Speedbird 245. Shorten your callsign only after the ground station has shortened it first.
Traps. Omitting DECIMAL; saying three instead of TREE; using ROGER as a readback; shortening your callsign unilaterally; saying take-off outside a take-off clearance.