HOME | CONTACT US
ACFC logo

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 pronunciation (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 Clark Tower . Operation can be up to an altitude requested by the pilot.

 

Operation into Clark Controlled Airspace requires a clearance from Clark Tower .

 

Pilots must be able to communicate clearly with Air Traffic Control located at Clark Tower .

 

Here are some examples that may assist in communicating with Clark Tower when entering Charlie 2.

 

Entry into Charlie 2

  1. Initial call from pilot

Whom am I calling                              Clark Tower

Who am I                                            “RP-S 1234”

 

  1. Answer from tower

Whom are they calling                        “RP-S1234

Who are they                                      Clark Tower”
Tell me what you want                        “Go ahead”

 

  1. 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

 

  1. 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”

 

  1. 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

  1. Initial call from pilot

Whom am I calling                              Clark Tower

Who am I                                            “RP-S 1234”

 

  1. Answer from tower

Whom are they calling                        “RP-S1234

Who are they                                      Clark Tower”
Tell me what you want                        “Go ahead”

 

  1. Your intentions
    Who am I                                            “1234”

Where am I                                         “Leaving Charlie 2, returning to Woodland at 500 feet

 

  1. 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:

 

Clark Tower                                                                       Pilot

 

“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 Woodland

“1234, what is your position?”                                           “1234, 5 miles NE Woodland , 500 feet”

“1234, say again”                                                              “1234, 5 miles NE Woodland , 500 feet”

 

2. giving your position

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 Santa Rosa , 500 feet”

“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)

Clark Tower , 1234, request higher altitude in Charlie 2, up to 1200 feet”

 

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 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 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 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 FIFE

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 FIFE ZERO DEGREES

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 FIFE ZERO ZERO (SQUAWK)


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.

REPORT Pass requested information.

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