Joined: 11 Dec 2005
|Posted: Sat Mar 30, 2013 11:38 am Post subject: Radiotelephony Procedures
Whenever times are given Co-ordinated Universal Time (UTC) is used Usually only the minutes are mentioned.
Aeronautical stations are identified by the name of the location followed by a suffix.
The suffix indicates the type of unit or service provided.
General aviation aircraft and private aircraft use the aircraft registration as the call sign.
Commercial aircraft normally use "telephony designator" approved by ICAO, followed by the flight number.
Provided that no confusion is likely to occur the ground station may abbreviate an aircraft call signs.
From this point onwards the aircraft may also use the abbreviated call sign.
Note however that it is the ATS unit which initiates the abbreviation and never the aircraft.
An aircraft is not allowed to change its type of call-sign or alter its call-sign during flight other than adopting ATC's abbreviation.
If necessary ATC may instruct an aircraft to change its call-sign.
In the initial call to an aircraft control tower and to the approach control unit, an aircraft in the Heavy wake turbulence category (max certificated take-off mass > 136,000 kg) must include the word "HEAVY" immediately after the aircraft call-sign.
The readability of transmissions is classified from 1 to 5 as follows:
1 = Unreadable
2 = Readable now and then
3 = Readable but with difficulty
4 = Readable
5 = Perfectly readable
When a ground station has to make test signals, such signals shall not continue for more than 10 seconds.
They shall be composed of spoken numbers (ONE, TWO, THREE etc) followed by the radio call sign of the station transmitting the test signals.
Such transmissions shall be kept to a minimum.