Aim
To gain a basic understanding of the requirements and use of aircraft radio and its operation in the field of aviation.
Objectives
At the end of this briefing you will be able to:
- State the authorisation granted by, and operating condition associated with, the aeronautical radio operator certificate
- Make a properly formatted broadcast appropriate to RPAS operations
Aircraft Radio
The Function of Aircraft Radio
When using in the context of aviation, it is sometimes called “aircraft radio” or “air-band radio“.
The use of a radio does not guarantee that all your communication problems will be resolved. A radio is a tool that we can choose to use, but we need to understand it’s limitations!
In electing to use a radio we assume:
- That the other aircraft/person actually has an appropriate radio.
- That all radios are working as expected.
- That the other radio is turned on.
- That the other radio is tuned to the same frequency.
- That the other radio has been set to a volume that can be heard.
- That the person monitoring the radio is actually listening to the radio.
- That what you intended the message to mean is what the other person understood the message to mean!
All of these things things to all be in place at the same time!
Definite “Show-Stopper” or Combination of Errors?
If the radio is turned off, or the ‘wrong’ frequency selected – this is a show-stopper!
More subtly, although it seems like the correct action is being taken, a combination of events may lead to disaster!
Aircraft Radio as a Threat & Error Countermeasure
Radio creates an opportunity for you to:
- Develop & maintain your situational awareness
- Identify and (possibly) manage threats
- Possibly communicate with potential threats and de-conflict
Aviation Task Prioritisation
Task prioritisation, also referred to as “Applied Risk Management”, consists of four primary tasks:
- Aviate
- Navigate
- Communicate
- Administrate
Radiotelephony
The Phonetic Alphabet
Letter | Word | Annunciation | Letter | Word | Annunciation |
---|---|---|---|---|---|
A | ALFA | AL far | N | NOVEMBER | No VEM ber |
B | BRAVO | BRAH voh | O | OSCAR | OSS cah |
C | CHARLIE | CHAR lee | P | PAPA | pah PAH |
D | DELTA | DELL tah | Q | QUEBEC | Keh BECK |
E | ECHO | ECK ho | R | ROMEO | ROW me oh |
F | FOXTROT | FOKS trot | S | SIERRA | See AIR rah |
G | GOLF | GOLF | T | TANGO | TANG go |
H | HOTEL | hoh TELL | U | UNIFORM | YOU nee form |
I | INDIA | IN dee A | V | VICTOR | VIK tah |
J | JULIETT | JEW lee ETT | W | WHISKY | WISS key |
K | KILO | KEY loh | X | X-RAY | ECKS ray |
L | LIMA | LEE mah | Y | YANKEE | YANG key |
M | MIKE | MIKE | Z | ZULU | ZOO loo |
Numbers
All numbers shall be transmitted by pronouncing each digit separately (e.g. 10 is WUN ZE-RO, 236 is TOO THREE SIX), except for:
- Whole hundreds
- 500 is FIFE HUN-dred
- Whole thousands
- 7,000 is SEV-en TOU-SAND
- Combinations of thousands and whole hundreds
- 7,500 is SEV-en TOU-SAND FIFE HUN-dred
Note: The meteorological way of expressing cloud cover is in eighths of the sky covered:
- Eighths in radio transmissions is expressed as “okta’s“.
- A little over half the sky covered, say 5/8, would be expressed as:
- FIFE-oktas
Number | Annunciation |
---|---|
50 | FIFE ZE-RO |
85 | AlT FIFE |
612 | SIX WUN TOO |
900 | NIN-er HUN-dred (whole hundreds only) |
3,000 | TREE TOU-SAND (whole thouands only) |
3,500 | TREE TOU-SAND FIFE HUN-dred |
12,000 | WUN TOO TOU-SAND |
12,700 | WUN TOO TOU-SAND SEV-en HUN-dred |
12,755 | WUN TOO SEV-en FIFE FIFE |
Standard Words & Phrases
Word/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 separation between messages transmitted to different aircraft in a very busy environment.
- 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: Used in the context of “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 or the message indicated the wrong information in this transmission, followed by the correct version “[wrong information] CORRECTION [correct information…]”.
- DISREGARD: Consider that transmission as not sent.
- HOW DO YOU: What is the readability of my transmission?
- I SAY AGAIN: I repeat for clarity or emphasis.
- MONITOR: Listen out on: [frequency].
- NEGATIVE: “No”, “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
- READ: The readability is:Unreadable
- Readable now and then
- Readable but with difficulty
- Readable
- Perfectly readable
- READ BACK: Repeat all, or the specified part a’ this message back to me exactly as received
- RE-CLEARED: A change has been made to your last clearance and this new clearance supersedes your previous clearance or part thereof.
- REPORT: Pass ore 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]
- SAY AGAIN: Repeat all or the following part at 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.
- WORDS TWICE: Can mean:
- As a request: Communication is difficult: “Please send every word or group of words twice.”
- As information: Since communication is difficult, every word or group of words in this message will be sent twice.
Radio Certification & Standard Calls
Aeronautical Radio Operator Certificate
Aeronautical Radio Operator Certificate (AROC) is specifically the Authorisation & Condition (CASR 64.035).
Why do we need it and what does an AROC allow us to do?
- It will allow us to transmit on a frequency of a kind used for the purpose of ensuring the safety of air navigation.
- You may only make a transmission if you are the holder of a current a current aviation English language proficiency assessment!
Operator Conduct
Authority | Responsibilities |
---|---|
Radiocommunications Act 1992 International Radio Regulations (published by International Telecommunications Union) | Maintain secrecy: Must preserve secrecy of communications to which the operator may become acquainted |
Unauthorised transmissions: – Interference – False of deceptive messages – Bad language – Unnecessary conversations – Harassing, alarming or affronting behaviour – Using radio as an explosives trigger |
Brevity and Clarity
Remember: when you make a transmission you are saying something for someone else to hear, and hopefully understand what you meant!
Some points (and common issues):
- Speak clearly.
- Position the microphone (know your equipment).
- Remember transmitter latency (press, pause-2-3, speak).
- Keep a constant volume – no need to yell (or swallow the mic).
- Keep an even rate of speech – in the excitement don’t speak quickly.
- Choose your words. Send enough to communicate, but do not flood the airwaves!
Paraphrasing George Bernard Shaw: The greatest fallacy with communication is that there was!
Declaring an Emergency
There are three types of emergency, and the pilot must preface his call with the appropriate words:
- MAYDAY: (repeated three times) for a distress call.
- PAN-PAN: (repeated three times for an urgency call.
- SECURITY: (repeated three times) for a safety call.
Distress Call (MAYDAY)
The MAYDAY call is derived from “m’aidez” – “help me”.
This is the absolute top priority call. It has priority over all others, and the word mayday should force everyone else into immediate radio silence.
Used when you require immediate assistance, and are in grave and immediate danger.
Any aircraft making an emergency radio call is to be given priority over all other aircraft/ground operations.
If a distress call is received radio operators may initiate or impose radio silence on all other stations.
This will be heard as:
- “STOP transmitting; MAYDAY”
- “ALL stations; STOP transmitting; MAYDAY”
This process ensures that all communications between the aircraft in distress are received by radio operators and emergency response teams clearly & accurately.
Construction of a MAYDAY Call
The distress message should contain as much of the following information as possible, and if possible in the sequence below:
- “MAYDAY MAYDAY MAYDAY”
- [Aircraft callsign] [Aircraft callsign] [Aircraft callsign]
- [Position and time]
- [Heading]
- [Airspeed]
- [Altitude]
- [Aircraft type]
- [Nature of distress]
- [Captain’s intentions]
- [Any other information that may facilitate the rescue]
Urgency Call (PAN-PAN)
Panne (pronounced: “pan”) is a breakdown, such as a mechanical failure.
Used when and emergency exists but does not require immediate assistance.
Typical Situations include:
- If you are experiencing navigational difficulties and require the urgent assistance of traffic services.
- If you have a passenger on board who is seriously ill and required urgent attention.
- If you see another airplane or ship the safety of which is threatened and urgent action is perhaps needed.
- If you are making an emergency change of level in controlled airspace and you may conflict with traffic below.
PAN – A Three-Letter Acronym
As a Three-Letter Acronym (TLA):
- “Possible assistance needed”
- “Pay attention now”
The TLA is derived from “pan” and is used in maritime and aeronautical radio communications courses as a mnemonic to radio and communications operators.
Note: it is very important remember the difference between mayday and pan-pan emergency communications.
Construction of a PAN-PAN Call
For an urgency call, the pilot should transmit:
- PAN-PAN PAN-PAN PAN-PAN
- [Callsign of a specific station or ‘all stations’]
- [Aircraft callsign]
- [Request for bearing, course or position, if required]
- [Position and time]
- [Heading]
- [Airspeed]
- [Altitude]
- [Aircraft type]
- [Available flight time]
- [Nature of emergency]
- [Captain’s intentions]
Security Call (SECURITY)
194 specifies that a message known as a safety signal shall be transmitted by an aircraft when considered necessary to advise the existence of a hazard to air navigation or hazardous meteorological conditions.
The specific circumstances for this call:
- The safety signal shall be transmitted when an aircraft wishes to transmit a message concerning the safety of navigation or to give important meteorological warnings.
- The safety signal shall be sent before the call and in the case of radiotelegraphy:
- Shall consist of 3 repetitions of the group TTT (- – -), sent with the letters of each group and the successive groups clearly separated from each other.
- Shall consist of the word “SECURITY”, repeated 3 times.
The “SECURITY” call may be used when there has been a breach in the security of the aircraft or its crew during flight.
An example of this would be an aggressive or agitated passenger on board who is interfering with the pilot.
Construction of a SECURITY Call
There are very few occasions when it would be necessary to transmit a security call, nevertheless you are required to know of the existence of this type of message in case it should ever become necessary to send one – or should one be received.
- Pilot:
- SECURITY SECURITY SECURITY
- Melbourne Centre
- Alfa November Kilo
- One two five decimal nine
- Severe turbulence and windshear experienced in the easter-lee of Wilson’s Promontory up to three thousand feet
- Melbourne ATS:
- Alfa November Kilo
- Melbourne Centre
- Copied
Radio Silence
An aircraft in distress or the appropriate ground station may impose radio silence on all other stations in the area or on any particular station causing interference, asking them to stop transmitting.
For example:
- All stations
- Stop transmitting
- MAYDAY
Types of Radio Calls
There are three main types of radio transmissions:
- Report:
- A report is generally made to a specific air traffic services unit.
- A response is expected.
- Broadcast:
- A broadcast is usually made in the form of a traffic advisory.
- May be addressed to “all stations“.
- No response is expected.
- Call:
- A call is made to a specific station.
- A response is expected.
Clearance and Read-Back
At certain times during a manned flight a clearance must be obtained from an air traffic control unit before proceeding. (e.g. takeoff, landing and taxi.)
If a manned aircraft intends to operate in controlled airspace it must obtain prior clearance.
The following clearances and instructions must be read back:
- An ATC route clearances in its entirety, and any amendments
- En route holding instructions.
- Any route or holding point specified in a taxi clearance.
- Any clearances and instructions to hold short of, enter, land on, conditional line-up.
- On, take-off from, cross, taxi or backtrack on, any runway.
- Any approach clearance.
- Assigned runway, altimeter settings directed to a specific aircraft, radio and radio navigation aid frequency instructions.
- Note: an “expectation” of the runway to be used is not to be read back.
- SSR (secondary surveillance radar) codes, data link logon codes.
- Level instructions, direction of turn, heading and speed instructions.
A Typical Read-Back Call
A “read back” is to:
- Confirm receipt of the transmission.
- Confirm that the pilot has understood the direction (no confusion or misunderstanding).
- To keep transmissions short, sharp and to the point.
For example:
- The call received from the tower:
- Delta Alfa November cleared to land.
- The pilot should respond:
- Cleared to land Delta Alfa November.
The pilot has “read back” the direction so as to ensure no confusion. The pilot has also given his call sign to again ensure the intended recipient has received the transmission and is acting on it.
Broadcast Calls
A call we might reasonably be expected to make:
- A broadcast is a traffic advisory passed to all interested parties on that frequency
- No response required.
- Unmanned aircraft must always have the word unmanned before aircraft type.
Format | Example |
---|---|
Location | Amberley |
<Location> Traffic | Amberley Traffic |
Aircraft Type | Unmanned Aircraft Possibly: small unmanned aircraft |
<Callsign> | [Unless assigned, we do not have a callsign] |
Position and Intentions | 7 miles north-west, not above 400 AGL, for the next 20 minutes |