Originally Posted by
caucatc
One more question is about the rules to read an aircraft registered number, according to the rule we have in China, if all the registered number is in words, such as ACGDS, I can read ADS for short, but what if some numbers in it? Such as ACGD1, A565T? Is there any rule for that?
According to 5.2.1.7.2.2.1 of ICAO Annex 10, Volume 2, abbreviated call signs consist of 'the first character of the registration and at least the last two characters of the call sign' or 'the telephony designator of the aircraft operating agency, followed by at least the last two characters of the call sign'. Since both letters and numbers are characters, the abbreviated call sign for a flight using the registration 'ACGD1' would be 'alpha delta one', respectively 'alpha five tango' for 'A565T'.