As rapidly as possible, to avoid tying up the frequency.
As clearly as possible to prevent words from running together.
As loudly as possible, to ensure clear reception.
As distinctly and mechanically as possible; do not use ordinary intonations and rhythm, break up the syllables instead and speak in a "robotic" voice for greater clarity.
Coordinated Universal Time
Denotes that time is approximate
Denotes that time is exact
One Five Thousand
One Five Zero Zero Zero
One Five Triple Oh
Runway numbers (e.g., Runway 12 = "Runway Twelve")
Numbers less than 100 (e.g., 21 = "twenty one")
Whole thousands (e.g., 4,000 = "four thousand")
Altitudes (e.g., 3,600' = "three thousand six hundred feet"
Flight levels (e.g., FL430 = "flight level four hundred thirty"
Cloud formation heights (e.g., 52 SCT ="fifty two hundred scattered"
Headings (e.g., Heading 210 = "Heading two hundred ten")
Words THIS IS
Your aircraft type + call sign
Ground station identifier (e.g., Charlottetown Radio)
Words ALL STATIONS ALL STATIONS ALL STATIONS
You are perfectly readable.
You are readable with difficulty
You are barely readable.
You are readable between 50% and 80% of the time.
118.0 (the station on which you've already established communications)
121.5 (emergency frequency)
126.7 (emergency frequency)
It separates parts of message (e.g., to different aicraft)
It signals that communication between two stations is over, and the pilot should switch to the next applicable frequency.
It indicates poor readability (transmission is breaking up).