Composition of Messages

5.2.1.6.1 Mobile Service Only Messages

Messages handled entirely by the aeronautical mobile service shall comprise the following parts in the order stated:

  1. call indicating the addressee and the originator (see 5.2.1.7.3);
  2. text (see 5.2.1.6.2.1.1).
Note The following examples illustrate the application of this procedure:

(call) NEW YORK RADIO SWISSAIR ONE ONE ZERO
(text) REQUEST SELCAL CHECK

Training reference only. Always defer to current approved manuals and official procedures.

or

(call) SWISSAIR ONE ONE ZERO NEW YORK RADIO
(text) CONTACT SAN JUAN ON FIVE SIX

5.2.1.6.2 AFTN Routing Messages

Messages requiring handling by the AFTN for part of their routing and similarly messages which are not handled in accordance with predetermined distribution arrangements (see 3.3.7.1) shall be composed as follows:

5.2.1.6.2.1 Messages Originated in Aircraft

When originated in an aircraft:

  1. call (see 5.2.1.7.3);
  2. the word FOR;
  3. the name of the organization addressed;
  4. the name of the station of destination;
  5. the text.

5.2.1.6.2.1.1 The text shall be as short as practicable to convey the necessary information; full use shall be made of ICAO phraseologies.

Note The following example illustrates the application of this procedure:

(call) BOSTON RADIO SWISSAIR ONE TWO EIGHT
(address) FOR SWISSAIR BOSTON
(text) NUMBER ONE ENGINE CHANGE REQUIRED

5.2.1.6.2.2 Retransmission to Aircraft

When a message, prepared in accordance with 4.4.2, is retransmitted by an aeronautical station to an aircraft in flight, the heading and address of the AFTN message format shall be omitted during the retransmission on the aeronautical mobile service.

5.2.1.6.2.2.1 Transmission Composition

When the provisions of 5.2.1.6.2.2 are applied, the aeronautical mobile service message transmission shall comprise:

  1. the text [incorporating any corrections (COR) contained in the AFTN message];
  2. the word FROM;
  3. the name of the originating organization and its location (taken from the origin section of the AFTN message).

5.2.1.6.2.2.2 Abbreviation Conversion

PANS. When the text of a message to be transmitted by an aeronautical station to an aircraft in flight contains approved ICAO abbreviations, these abbreviations should normally be converted during the transmission of the message into the unabbreviated words or phrases which the abbreviations represent in the language used, except for those which, owing to frequent or common practice, are generally understood by aeronautical personnel.

Note The abbreviations which constitute the exceptions mentioned in 5.2.1.6.2.2.2 are specifically identified in the abbreviations encode sections of the PANS-ABC (Doc 8400).