8.1 Radio Telephony general

INTRODUCTION

8.1.1 The importance of adhering to the procedures prescribed in this section cannot be over emphasised. The investigations of the near-collision panel have revealed that misunderstandings introduced through incorrect R/T procedures have been responsible for more near-collision than any other single cause.

8.1.2 The phraseology and procedures detailed in this section are to be adhered to in order to ensure uniformity, they may, however, be modified or extended by Air Traffic Controllers as occasion demands, but such modifications and extensions should not prejudice their basic meaning or intention.

8.1.3 In order to deal with any unusual situation which may occur, the Controller must exercise his best judgement in the use of additional or other phraseology. In such cases he should use supplementary rather than substitute phrases.

8.1.4 Efforts should be made to keep transmissions as brief as possible, and to dispense with all unnecessary words, phrases, etc. which can quickly lead to frequency congestion.

RADIO GUARD

Note: Do not confuse the use of the word ‘Guard’ in this section, meaning maintaining a listening watch, with the GUARD frequency on IVAO.

8.1.5 All ATC’s shall maintain a continuous guard on the appropriate radio frequencies throughout their tour of duty.

8.1.6 Should it be necessary to suspend the radio guard for any reason, such as to inspect the movement area, etc., the break in the radio guard shall be kept as short as possible.

8.1.7 Any aircraft in radio contact with the station shall be informed that there will be a break in the radio guard.

8.1.8 If practicable another station should be asked to listen out for, and to answer any calls during breaks in the radio guard.

SPEECH TECHNIQUE

8.1.9 Correct enunciation of words, spoken at a uniform rate in a voice pitched somewhat higher than normal but preserving the rhythm of ordinary conversation will do much to assist satisfactory reception of mechanically reproduced speech. Microphones at present provided to ATC are directionally functioning and ATC’s should therefore speak directly into them.

8.1.10 To avoid clipped transmissions, particularly where the transmitter is remote from the microphone, it is important to depress the transmit switch fully before speech is commenced and to avoid releasing it before the transmission is completed. Controllers should endeavour to use clear concise sentences and to eradicate such obvious faults as hesitation sounds, verbosity, lowering of voice, blurring of consonants, etc. This will ensure maximum efficiency and prevent irritating repetitions.

8.1.11 It is correct procedure for controllers to announce identity on all telephone calls: with incoming calls it is the opening remark and with outgoing calls the reply to the recipient’s announcement of identity.

8.1.12 It is just as important that this procedure’s not relaxed for direct telephone lines because mistaken identity can occur when another line has inadvertently been left open from a previous call.

8.1.13 The identity to be used is that of the function relative to the telephone extensions being used. On outside calls the identity should be given in full, for example ‘This is Johannesburg Air Traffic Control’ but on direct lines, where it will require no further amplification, it may be abbreviated to ‘Johannesburg’.

LETTERS

8.1.14 The ICAO word spelling alphabet is given below with the pronunciation in parenthesis for each letter; the syllables requiring emphasis being underlined. This alphabet is to be used at all times when it is required to indicate letters except for particular letter groups which by every-day use have become unmistakable, e.g. VOR, NDB, ILS, QNH, ETA, etc.

Letter	R/T	Pronunciation
A	ALPHA	AL FAH
B	BRAVO	BRAH VOH
C	CHARLIE	CHAR LEE
D	DELTA	DELL TAH
E	ECHO	ECK OH
F	FOXTROT	FOKS TROT
G	GOLF	GOLF
H	HOTEL	HOH TELL
I	INDIA	IN DEE AH
J	JULIET	JEW LEE ET
K	KILO	KEY LOH
L	LIMA	LEE MAH
M	MIKE	MIKE
N	NOVEMBER	NO VEM BER
O	OSCAR	OSS CAH
P	PAPA	PAH PAH
Q	QUEBEC	KEH BECK
R	ROMEO	ROW ME OH
S	SIERRA	SEE AIRRAH
T	TANGO	TANG GO
U	UNIFORM	YOU NEE FORM
V	VICTOR	VIKTAH
W	WHISKEY	WISS KEY
X	XRAY	ECKS RAY
Y	YANKEE	YANG KEY
Z	ZULU	ZOO LOO

NUMERALS

8.1.15 The phonetic representations of figures and associated words are given below.

0	ZE-RO
1	WUN
2	TOO
3	TREE
4	FOWER
5	FIFE
6	SIX
7	SEVEN
8	AIT
9	NINER
HUNDRED	HUN DRED
THOUSAND	TOU SAND
DECIMAL	DAY SEE MAL

8.1.16 All numbers, except those which are whole hundreds or thousands, are to be spoken by pronouncing each figure separately. Decimals will be indicated where necessary.

TIME

8.1.17 UTC and the 24-hour clock will be used at all times.

8.1.18 When speaking a time value, normally only the minutes of the hour are required; each figure being pronounced separately. However, if there is any possibility of confusion the full four-figure group will be spoken.

E.g. time check at 45 or at 0845.

STANDARD SPEECH ABBREVIATIONS

8.1.19 The words and phrases shown in the table below are to be used whenever applicable.

 

Phrase	Meaning
ACKNOWLEDGE	Let me know that you have received and understood this message.
AFFIRM	Yes.
APPROVED	Permission for proposed action granted.
BREAK	I hereby indicate the separation between portions of the message. (To be used where there is no clear distinction between the text and other portions of the message).
BREAK BREAK	I hereby indicate the separation between messages transmitted to different aircraft in a very busy environment.
CANCEL	Annul the previously transmitted clearance.
CHECK	Examine a system or procedure. (Not to be used in any other context. No answer is normally expected).
CLEARED	Authorised to proceed under the conditions specified.
CONFIRM	I request verification of: (clearance, instruction, action, information)
CONTACT	Establish communications with …
CORRECT	"True" or "Accurate"
CORRECTION	An error has been made in this transmission (or message indicated). The correct version is …
DISREGARD	Ignore
GO AHEAD	Proceed with your message. Note: Not used whenever the possibility exists of misconstruing "GO AHEAD" as an authorisation for an aircraft to proceed. The phrase "GO AHEAD" may be omitted and, in its place, a response made by using the calling aeronautical station’s call sign followed by the answering aeronautical station’s call sign.
HOW DO YOU READ	What is the readability of my transmission?
I SAY AGAIN	I repeat for clarity or emphasis.
MAINTAIN	Continue in accordance with the condition(s) specified or in its literal sense, e.g. Maintain VFR.
MONITOR	Listen out on (frequency).
NEGATIVE	No or Permission not granted or That is not correct or Not capable.
OVER	My transmission is ended, and I expect a response from you. (Not normally used in VHF communications).
OUT	This exchange of transmissions is ended and no response is expected. (Not normally used in VHF communications).
READ BACK	Repeat all, or the specified part, of this message back to me exactly as received.
RECLEARED	A change has been made to your last clearance and this new clearance supersedes your previous clearance or part thereof.
REPORT	Pass me the following information …
REQUEST	I would like to know … or I wish to obtain …
ROGER	I have received all of your last transmission. Note: Under no circumstances to be used in reply to a question requiring READ BACK or a direct answer in the affirmative (AFFIRM) or negative (NEGATIVE).
SAY AGAIN	Repeat all, or the following part, of your last transmission.
SPEAK SLOWER	Reduce your rate of speech.
STAND BY	Wait and I will call you. Note: The caller would normally re-establish contact if the delay is lengthy. STANDBY is not an approval or denial.
WILCO	Abbreviation for ‘will comply’. I understand your message and will comply with it.
WORDS TWICE	a) As a request: Communication is difficult. Please send every word, or word group, twice. b) As information: Since communication is difficult every word or group of words, in this message will be sent twice.