Aviation radio communication
Over the years international conventions for aviation radio communication have been established. They have one aim: Understanding. Because misunderstanding can cause disasters.
General points
- Brevity: Say what you want to say in the shortest possible way
- Clarity: Be as clear as you can
- Acknowledgement: Acknowledge each communication with your call sign
- Proper phraseology: Use approved words and phrases. Jargon, chatter and "CB" slang have no place in ATC communications.
Technique
- Listen before you transmit: Make sure there not already a conversation going on your frequency.
- Think before you transmit: Be clear in your mind what information you want to send. Also think about the shortest and clearest way of saying it.
- Good pronunciation: Speak slowly in a clear voice, use standard English and standard pronounciation (avoid local dialects and foreign accents as much as you can)
- Wait before trnasmitting again: Controllers can sometimes only answer after a while
- Be aware of the sounds and noises you hear: You must know how it sounds in your own headset when you transmit and when you don't. This will allow you to know when your transmit key is stuck ("stuck mike"). If a station is stuck in transmission mode it blocks the whole frequency, endangering airtraffic in a large area.
Guidelines
1. Radio calls around Woodland Airpark
2. Giving your position
3. General Radio Telephony Procedures including letters, numbers and phrases (Extract from CAP 413)
1. Radio call to request permission to leave Charlie 1
Operation
of Club aircraft is permitted unrestricted in Charlie 1 up to 800 feet. Entry
into Charlie 2, 3 and 4 requires approval from
Operation
into Clark Controlled Airspace requires a clearance from
Pilots
must be able to communicate clearly with Air Traffic Control located at
Here
are some examples that may assist in communicating with
Entry into
Charlie 2
- Initial call from pilot
Whom am I
calling “
Who
am I “RP-S
1234”
- Answer from tower
Whom are
they calling “RP-S1234”
Who are they “
Tell me what you want “Go
ahead”
- Pilot intentions
Who
am I “1234”
(After initial contact the letters can be omitted)
Where am I “Departed
Woodland, heading north east, 500 feet”
What
I want “Request
to enter Charlie 2”
- Approval from tower
Whom are
they calling “1234” (After initial contact the letters can be omitted)
What you allowed to do “Entry
into Charlie 2 approved”
Further
instructions “Remain
below 800 feet and VFR at all times”
- Acknowledgement from pilot
Repeat
the approval “Enter
Charlie 2, remain below 800 feet, VFR at all times”
Who
am I “1234”
(Call sign is placed at the end of the transmission)
Departing Charlie 2
- Initial call from pilot
Whom am I
calling “
Who
am I “RP-S
1234”
- Answer from tower
Whom are
they calling “RP-S1234”
Who are they “
Tell me what you want “Go
ahead”
- Your intentions
Who am I “1234”
Where am I “Leaving
Charlie 2, returning to
- Acknowledgment from tower
Whom are they calling “1234”
Pilot intentions understood “Roger”
Additional instructions “Report after landing Woodland” or
“Clear
to leave frequency”
Other instructions and requests from tower and
appropriate response:
“1234, type
of aircraft?” “1234,
Ultralight, Hawk”
“1234, request duration of flight” “1234,
30 minutes duration”
“1234”, QNH
1013 hectopascals, 29.92 inches” “QNH
1013, 1234”
“1234,
report leaving Charlie 2” “Report
leaving Charlie 2, 1234”
“1234, say
your intentions” “1234,
Landing at
“1234, what
is your position?” “1234,
5 miles
“1234, say
again” “1234,
5 miles
The tower may ask for your position. In an ultralight
it is difficult to give directions, headings or radials. The tower is happy if
you give your position by estimating the direction to Mt Arayat, any other
suitable landmark or town. Examples:
“1234 over
“2 miles north-east of Mt Arayat, 600 ft. (should not
report higher than 800 ft as ultra lights only have approval to operate up to 800 ft. If higher is
desired, request from tower)
“
Basic rules in radio communication:
Speak clear, with normal voice and no “eeeh” or
“uuuh”.
Try to use as few words as possible.
Always listen carefully and talk only when nobody else
is transmitting.
Can omit the “RP-S” after initial
contact with tower.
Instructions, clearances and QNH/altimeter setting
must be repeated. (“Cleared to…” “QNH 1013”).
The aircraft call sign is placed at the end of the
transmission for readback of clearances and instructions.
3. General Radio Telephony Procedures (Extract from CAP 413)
Introduction
Radiotelephony provides the means by
which pilots and ground personnel communicate with each other. Used properly,
the information and instructions transmitted are of vital importance in
assisting in the safe and expeditious operation of aircraft. However, the use
of non-standard procedures and phraseology can cause misunderstanding.
Incidents and accidents have occurred in which a contributing factor has been
the misunderstanding caused by the use of non-standard phraseology. The importance of using correct and precise standard phraseology cannot
be over-emphasized.
Transmitting Technique
The following transmitting techniques
will assist in ensuring that transmitted speech is clearly and satisfactorily
received.
a) Before transmitting check that the
receiver volume is set at the optimum level and listen out on the frequency to
be used to ensure that there will be no interference with a transmission from
another station.
b) Be familiar
with microphone operating techniques and do not turn your head away from it
whilst talking or vary the distance between it and your mouth. Severe distortion
of speech may arise from:
i) Talking too close to the
microphone
ii) Touching the microphone with the
lips
iii) Holding the microphone or boom
(of a combined headset/microphone system).
c) Use a normal conversation tone,
speak clearly and distinctly.
d) Maintain an even rate of speech
not exceeding 100 words per minute. When it is known that elements of the
message will be written down by the recipients, speak at a slightly slower
rate.
e) Maintain the speaking volume at a
constant level.
f) A slight pause before and after
numbers will assist in making them easier to understand.
g) Avoid using hesitation sounds such
as ‘er’.
h) Depress the transmit switch fully
before speaking and do not release it until the message is complete. This will
ensure that the entire message is transmitted. However, do not depress transmit
switch until ready to speak.
i) Be aware that
the mother tongue of the person receiving the message may not be English.
Therefore, speak clearly and use standard radiotelephony (RTF) words and phrases
wherever possible.
One of the most irritating and
potentially dangerous situations in radiotelephony is a ‘stuck’ microphone
button. Operators should always ensure that the button is released after a
transmission and the microphone placed in an appropriate place that will ensure
that it will not inadvertently be switched on.
After a call has been made, a period
of at least 10 seconds should elapse before a second call is made. This should
eliminate unnecessary transmissions while the receiving station is getting
ready to reply to the initial call.
Letters
The words in the table below shall be
used when individual letters are required to be transmitted.
A Alpha
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
J Juliet JEW LEE ETT
K Kilo KEY LOH
L
M Mike MIKE
N November NO VEM BER
O Oscar
P Papa PAH PAH
Q
R Romeo ROW ME OH
S Sierra SEE AIR RAH
T Tango TANG GO
U Uniform YOU NEE FORM
V Victor VIK TAH
W Whiskey WISS KEY
X X-ray ECKS RAY
Y Yankee YANG KEE
Z Zulu ZOO LOO
Numbers
0 ZERO
1 WUN
2 TOO
3 TREE
4 FOWER
5
6 SIX
7 SEVEN
8 AIT
9 NINER
Decimal DAYSEEMAL
Hundred HUN DRED
Thousand TOUSAND
BA246 Speedbird Two Four Six
SPEEDBIRD TOO FOWER SIX
FL 100 Flight Level One Hundred FLIGHT LEVEL WUN HUN DRED
FL 180 Flight Level One Eight Zero FLIGHT
LEVEL WUN AIT ZERO
150 Degrees One Five Zero Degrees WUN
18 Knots One Eight Knots WUN AIT
KNOTS
122.1 One Two Two Decimal One WUN TOO
TOO DAYSEEMAL WUN
6500 Six Five Zero Zero SIX
Words
and phrases
ACKNOWLEDGE Let me know that you have
received and understood this message.
AFFIRM Yes.
APPROVED Permission for proposed
action granted.
BREAK Indicates the separation between messages.
BREAK BREAK Indicates the separation
between messages transmitted to different aircraft in a busy environment.
CANCEL Annul the previously
transmitted clearance.
CHANGING TO I intend to call . . . (unit) on . . . (frequency).
CHECK Examine a system or procedure.
(Not to be used in any other context. No answer is normally expected.)
CLEARED Authorized to proceed
under the conditions specified.
CLIMB Climb and maintain.
CONFIRM I request verification of: (clearance, instruction, action, information).
CONTACT Establish communications with
... (your details have been passed).
CORRECT True or accurate.
CORRECTION An error has been made in this transmission (or message indicated). The correct
version is...
DESCEND Descend and maintain.
DISREGARD Ignore.
HOLD SHORT Stop before reaching the
specified location .
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.
OUT This exchange of transmissions is ended and no response is expected.
OVER My transmission
is ended and I expect a response from you.
PASS YOUR MESSAGE Proceed with your
message.
READ BACK Repeat all, or the
specified part, of this message back to me exactly as received.
REQUEST I should like to know ... or
I wish to obtain...
ROGER I have received all your last
transmission.
Note:
Under no circumstances to be used in reply to a question requiring 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.
STANDBY Wait and I will call you.
UNABLE I cannot comply with your
request, instruction or clearance.
Unable is
normally followed by a reason.
WILCO I understand your message and
will comply with it (abbreviation for will comply)
WORDS TWICE As a request: Communication is difficult. Please send every word
twice.
Aeronautical stations are identified
by the name of the location followed by a suffix. The suffix indicates the type
of service being provided.
When satisfactory communication has
been established, and provided that it will not be
confusing, the name of the location or the callsign suffix
may be omitted.
Approach Control APPROACH
Aerodrome Control TOWER
Ground Movement Control GROUND
Flight Information INFORMATION
Air/Ground Communication Service RADIO