R/T phrasing (xhtml w3c 12/09)

VHF radiocommunications

Radiotelephony phrasing
— aviation English

Rev. 11 — page content was last changed 18 August 2010
Page edited by RA-Aus member Dave Gardiner www.redlettuce.com.au

Content

2.1 Radiotelephony pronunciation
2.2 Expressing time
2.3 Standard words and phrases

It is most important that the intent of each aviation radiotelephony transmission is clearly stated — and readily understood and remembered by recipients. Putting the necessary words together before transmitting, keeping it brief, using the standard terminology and phrasing — aviation English — and always using your complete and correct call sign are the keys to communicating useful operational information.

Most of the material in this page is extracted from the Aeronautical Information Publication Australia book [AIP], published by the Aeronautical Information Service of Airservices Australia. The relevant section in the AIP is noted in the text headings. The full and up-to-date text is available online at the Airservices Australia website; to access AIP please first read this paragraph in the 'Flight planning and navigation' guide.

2.1 Radiotelephony pronunciation (AIP GEN 3.4 section 4)

A phonetic alphabet is used in radiotelephony [R/T] communications when transmission of individual letters is required. This phonetic alphabet was originally developed by the North Atlantic Treaty Organisation as an international alphabet for use by the armed forces of the NATO nations.

Letters

Phonetic	Pronunciation	Phonetic	Pronunciation
A ALFA	AL fah	B BRAVO	BRAH voh
C CHARLIE	CHAR lee	D DELTA	DELL tah
E ECHO	ECK ho	F FOXTROT	FOKS trot
G GOLF	GOLF	H HOTEL	hoh TELL
I INDIA	IN dee A	J JULIETT	JEW lee ETT
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 AIR rah	T TANGO	TANG go
U UNIFORM	YOU nee form	V VICTOR	VIK tah
W WHISKY	WISS key	X X-RAY	ECKS ray
Y YANKEE	YANG key	Z ZULU	ZOO loo

Numbers

The R/T pronunciation of numbers should be the following phonetic form:

0 ZE–RO		5 FIFE
1 WUN		6 SIX
2 TOO		7 SEV en
3 TREE		8 AIT
4 FOW er		9 NIN er
Hundred HUN dred
Thousand TOU SAND
Decimal DAY SEE MAL

Expressing numbers

All numbers used in the transmission of altitude, cloud height and visibility information — that contain whole hundreds and whole thousands — must be transmitted by pronouncing each digit in the number of hundreds or thousands followed by the word HUNDRED or THOUSAND as appropriate, but without the suffix 'feet'; e.g.:

ALTITUDE:
(800 feet) – "EIGHT HUNDRED"
(1500 feet) – "ONE THOUSAND FIVE HUNDRED"
(4750 feet) – "FOUR SEVEN FIVE ZERO"
(10 000 feet) – "ONE ZERO THOUSAND"
CLOUD HEIGHT:
(2200 feet )– "TWO THOUSAND TWO HUNDRED"
(4300 feet) – "FOUR THOUSAND THREE HUNDRED"
VISIBILITY:
(1500 feet) – "ONE THOUSAND FIVE HUNDRED"
(3000 feet) – "THREE THOUSAND"

All other numbers, except VHF frequencies, must be transmitted by pronouncing each digit separately; e.g.:

HEADING (the words 'degrees' and 'magnetic' are not transmitted):
(150° M) – "ONE FIVE ZERO"
(080° M) – "ZERO EIGHT ZERO"
(305° M) – "THREE ZERO FIVE"
WIND DIRECTION (the word 'degrees' is transmitted):
(020°) – "ZERO TWO ZERO DEGREES"
(100°) – "ONE ZERO ZERO DEGREES"
(210°) – "TWO ONE ZERO DEGREES"
WIND SPEED:
(10 knots) – "ONE ZERO KNOTS"
(15 knots, gusting to 25) – "ONE FIVE KNOTS GUSTING TWO FIVE"
ALTIMETER SETTING – QNH:
(995 hPa) – "NINE NINE FIVE"
(1010 hPa) – "ONE ZERO ONE ZERO"
(1027 hPa) – "ONE ZERO TWO SEVEN"

VHF frequencies are a bit unusual because 25 kHz spacing is gradually being introduced in Australia as frequency congestion becomes apparent. However, currently only 50 kHz spacing operates in Class G airspace.

If the frequency is a 50 kHz multiple then all significant digits are transmitted including the first zero after the decimal point:
(122.0) – "ONE TWO TWO DECIMAL ZERO"
(122.15) – "ONE TWO TWO DECIMAL ONE FIVE"
(126.05) – "ONE TWO SIX DECIMAL ZERO FIVE"
(126.7) – "ONE TWO SIX DECIMAL SEVEN"

If the frequency is a 25 kHz multiple (i.e. the second and third digits after the decimal point are 25 or 75) then the sixth digit is inferred as 'FIVE' and not transmitted:
(122.025) – "ONE TWO TWO DECIMAL ZERO TWO"
(122.525) – "ONE TWO TWO DECIMAL FIVE TWO'
(122.075) – "ONE TWO TWO DECIMAL ZERO SEVEN"
(122.675) – "ONE TWO TWO DECIMAL SIX SEVEN"

2.2 Expressing time (AIP GEN 3.4)

The 24-hour clock system is used in R/T transmissions. The hour is indicated by the first two figures and the minutes by the last two figures, e.g.:

(0001 hrs) – "ZERO ZERO ZERO ONE"
(1920 hrs) – "ONE NINE TWO ZERO".

Time may be stated in minutes only (two figures) in R/T communications when no misunderstanding is likely to occur.

Current time in use at a station is stated to the nearest minute in order that pilots may use this information for time checks.

Australian civil aviation uses Coordinated Universal Time [UTC] for all operations. The suffix 'Zulu' is appended when procedures require a reference to UTC, e.g.:

(0920 UTC or 0920Z) – "ZERO NINE TWO ZERO ZULU"
(0115 UTC or 0115Z) – "ZERO ONE ONE FIVE ZULU".

To convert from Australian Standard Time to UTC:

Eastern Standard Time subtract 10 hours
Central Standard Time subtract 9.5 hours
Western Standard time subtract 8 hours.

2.3 Standard words and phrases (AIP GEN 3.4)

The following words and phrases are to be used in radiotelephony communications, as appropriate, and have the meaning given:

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).
CANCEL	Annul the previously transmitted clearance.
CHECK	Examine a system or procedure (no answer is normally expected).
CLEARED	Authorised to proceed under the conditions specified.
CONFIRM	Have I correctly received the following ... ? or Did you correctly receive this message ... ?
CONTACT	Establish radio contact with ...
CORRECT	That is correct.
CORRECTION	An error has been made in this transmission (or message indicated) the correct version is ...
DISREGARD	Consider that transmission as not sent.
HOW DO YOU READ	What is the readability (i.e. clarity and strength) of my transmission? See 'clarity of 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".
MAYDAY	My aircraft and its occupants are threatened by grave and imminent danger and/or I require immediate assistance.
MONITOR	Listen out on (frequency).
NEGATIVE	"No" or "Permission is not granted" or "That is not correct".
OVER	My transmission is ended and I expect a response from you ( not normally used in VHF communication).
OUT	My transmission is ended and I expect no response from you ( not normally used in VHF communication).
PAN PAN	I have an urgent message to transmit concerning the safety of my aircraft or other vehicle or of some person on board or within sight but I do not require immediate assistance.
READ BACK	Repeat all, or the specified part, of this message back to me exactly as received.
REPORT	Pass me the following information.
REQUEST	I should like to know or I wish to obtain.
ROGER	I have received all of your last transmission (Under NO circumstances to be used in reply to a question requiring READ BACK or a direct answer in the affirmative or negative. Do not use the term 'COPY THAT' or double click the transmit button.)
SAY AGAIN	Repeat all or the following part of your last transmission
SPEAK SLOWER	Reduce your rate of speech.
STANDBY	Wait and I will call you.
VERIFY	Check and confirm with originator.
WILCO	I understand your message and will comply with it. (Do not use the term 'COPY THAT' or double click the transmit button.)