¶ Introduction
This document applies to both ATC and Pilots.
Our radio communication should be as short yet meaningful as possible without any unnecessary additives. It shall take as little radio time as possible, especially in congested sectors. This is why aviation phraseology was designed. It is a set of approximately 300 words and phrases to eliminate transmission's ambiguity as much as possible.
¶ Learning Phraseology
Although the best learning is through experience and repeating what others say like from LiveATC, it doesn't necessarily have to be correct all the time. Therefore we strongly advise you to first read the 2 documents listed below in order to have a good theoretical background.
- ICAO DOC 9432 - Podręcznik Frazeologii (PL/ENG)
- ICAO DOC 4444 - Rozdział 12 (Frazeogia) (PL/ENG)
¶ Basic Rules Of Radio Transmission:
- Use standard phraseology.
- Don’t transmit anything which is not related to the flight nor phraseology (though there are certain conditions in which it is ok to use plain language).
- Additives like: “you are” “please” “you can” “if you want you can” etc. are incorrect and completely unnecessary.
“I’ve once heard it on the radio”
Remember that every controller (and pilot) has habits, some of which might be old and incorrect. So, unfortunately, not everything you hear on the radio (even in real world) might be 100% correct. Therefore you should always refer to manuals and official documents rather than what you hear. Keep in mind that phraseology develops and changes, and so should you.
¶ Transmitting Technique
The following transmitting techniques will assist in ensuring that transmitted speech is clear and satisfactorily received:
- Before transmitting, listen out on the frequency to be used to ensure that there will be no interference with a transmission from another station;
- Be familiar with good microphone operating techniques;
- Use a normal conversational tone, and speak clearly and distinctly;
- 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 recipient, speak at a slightly slower rate;
- Maintain the speaking volume at a constant level;
- A slight pause before and after numbers will assist in making them easier to understand;
- Avoid using hesitation sounds such as “er”;
- Depress the transmit switch fully before speaking and do not release it until the message is completed. This will ensure that the entire message is transmitted;
- The transmission of long messages should be interrupted momentarily from time to time to permit the transmitting operator to confirm that the frequency in use is clear and, if necessary, to permit the receiving operator to request repetition of parts not received.
¶ Transmission of letters
To expedite communications, the use of phonetic spelling should be dispensed with if there is no risk of this affecting correct reception and intelligibility of the message.
With the exception of the telephony designator and the type of aircraft, each letter in the aircraft call sign shall be spoken separately using the phonetic spelling.
The following words shall be used when using the phonetic spelling:
| Letter | Word | Letter | Word |
|---|---|---|---|
| A | Alpha | N | November |
| B | Bravo | O | Oscar |
| C | Charlie | P | Papa |
| D | Delta | Q | Quebec |
| E | Echo | R | Romeo |
| F | Foxtrot | S | Sierra |
| G | Golf | T | Tango |
| H | Hotel | U | Uniform |
| I | India | V | Victor |
| J | Juliett | W | Whiskey |
| K | Kilo | X | X-ray |
| L | Lima | Y | Yankee |
| M | Mike | Z | Zulu |
¶ Transmission of numbers
When the language used for communication is English, numbers shall be transmitted using the
following pronunciation:
| Numeral or numeral element | Pronunciation |
|---|---|
| 0 | ZE-RO |
| 1 | WUN |
| 2 | TOO |
| 3 | TREE |
| 4 | FOW-er |
| 5 | FIFE |
| 6 | SIX |
| 7 | SEV-en |
| 8 | AIT |
| 9 | NIN-er |
| Decimal | DAY-SEE-MAL |
| Hundred | HUN-dred |
| Thousand | TOU-SAND |
With some exceptions, all digits shall be transmitted by pronouncing each digit separately.
All numbers used in the transmission of altitude, cloud height, visibility and runway visual range
(RVR) information, which contain whole hundreds and whole thousands, shall be transmitted by pronouncing
each digit in the number of hundreds or thousands followed by the word HUNDRED or THOUSAND as
appropriate. Combinations of thousands and whole hundreds shall be transmitted by pronouncing each digit in
the number of thousands followed by the word THOUSAND followed by the number of hundreds followed by
the word HUNDRED.
¶ Transmisison of Frequencies
Frequencies shall be pronounced using either 4 or 6 digits separately
¶ Transmission of callsigns
¶ Call signs for aeronautical stations
Aeronautical stations are identified by the name of the location followed by a suffix. The suffix indicates the type of unit or service provided.
| Unit of service | Call sign Suffix |
|---|---|
| Area control centre | CONTROL |
| Radar (in general) | RADAR |
| Approach control | APPROACH |
| Approach control radar arrivals | ARRIVAL |
| Approach control radar departures | DEPARTURE |
| Aerodrome control | TOWER |
| Surface movement control | GROUND |
| Clearance delivery | DELIVERY |
| Precision approach radar | PRECISION |
| Direction finding station | HOMER |
| Flight information service | INFORMATION |
| Apron control | APRON |
| Company dispatch | DISPATCH |
| Aeronautical station | RADIO |
When satisfactory communication has been established, and provided that it will not be confusing, the name of the location or the call sign suffix may be omitted.
¶ Aircraft call signs
An aircraft call sign shall be one of the following types:
- the characters corresponding to the registration marking of the aircraft; (i.e. SP-ABC)
- the telephony designator of the aircraft operating agency, followed by the flight identification (max 4 characters). (i.e. LOT345).
¶ Short call signs
After satisfactory communication has been established, and provided that no confusion is likely to occur, specified aicraft call signs may be abbreviated as follows:
- the first and at least the last two characters of the aircraft registration (i.e. SP-ABC as S-BC);
Rules when using short call signs:
- An aircraft shall use its abbreviated call sign only after it has been addressed in this manner by the aeronautical station.
- An aircraft shall not change its type of call sign during flight except when there is a likelihood that confusion may occur because of similar call signs; in such cases, an aircraft may be instructed by an air traffic control unit to change the type of its call sign temporarily.
- Aircraft in the heavy wake turbulence category shall include the word “HEAVY” immediately after the aircraft call sign in the initial contact between such aircraft and ATS units.
¶ Standard words and phrases
The following words and phrases shall be used in radiotelephony communications as appropriate and shall have the meaning given below:
| Word/Phrase | Meaning |
|---|---|
| APPROVED | “Permission for proposed action granted.” |
| BREAK | “I hereby indicate the separation between 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.” |
| CLEARED | “Authorized 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.” |
| 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.” |
| 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 should like to know . . .” or “I wish to obtain . . .” |
| ROGER | “I have received all of your last transmission.” |
| 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.” |
| WILCO | (Abbreviation for “will comply”.) “ I understand your message and will comply with it.” |
| WORDS TWICE | 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.” |
¶ Read-back
Read-back requirements have been introduced in the interests of flight safety. The stringency of the read-back requirement is directly related to the possible seriousness of a misunderstanding in the transmission and receipt of ATC clearances and instructions. Strict adherence to read-back procedures ensures not only that the clearance has been received correctly but also that the clearance was transmitted as intended. It also serves as a check that the right aircraft, and only that aircraft, will take action on the clearance.
The following shall always be read back:
- ATC route clearances;
- clearances and instructions to enter, land on, take off from, hold short of, cross and backtrack on any runway; and
- runway-in-use, altimeter settings, SSR codes, level instructions, heading and speed instructions and, whether issued by the controller or contained in ATIS broadcasts, transition levels.
Saying "Roger" is NOT a read-back. You need to read-back (with a few exceptions) everything that controller has told you.
What shall not be read back:
- Wind information given with take off / landing clearance.
- "Stand by" - instead of cogesting radio with "standing by" just do it.
¶ What if I didn't understand something?
Don't be afraid to say the phrase "SAY AGAIN" if some or all of transmissions content was unreadable to you.
¶ Common mistakes
Reading back wind information. - This is only an information.
Saying With You on initial contact - there is no such phrase in phraseology.
Reading back standing by. Instead - just do it.
Altitude Flight Level - It's either Altitude or Flight Level, depending if you're using QNH/QNE as a reference.
Affirmitive - you shall use word Affirm not to confuse with negative.
Abbreviating short call signs in any other form that 1st and last 2 characters of the aircraft registration (example of correct form: SP-NIC as S-IC).
Descending TO three thousand feet / descending TO two three zero (FL) - there is a very high chance of confusion here. You shouldn't add "TO" as a preposition. However if you really need to, add Altitude or Flight Level in between - Descending to ALTITUDE three thousand feet / Descending to FLIGHT LEVEL Two Three Zero.
Incorrect read-back - a correct read-back is only such that it ensures the sender (ATC) that the receiver (pilot) has received and fully understood all information/clearance/instruction.
Readibility zero by five. - It is neither "0" and neither by - just one / two / three / four or five.
¶ How to avoid them?
Simple yet comprehensive answer: use only words and phrases laid down in phraseology.
¶ Radio Check
Test transmissions should take the following form:
- the identification of the aeronautical station being called;
- the aircraft identification;
- the words "RADIO CHECK"; and
- the frequency being used.
Replies to test transmissions should be as follows:
- the identification of the station calling;
- the identification of the station replying; and
- information regarding the readability of the transmission.
The readability of transmissions should be classified in accordance with the following
readability scale:
- Unreadable
- Readable now and then
- Readable but with difficulty
- Readable
- Perfectly readable
Pilot: Okęcie Delivery LOT345 radio check on frequency 121.905.
ATC: LOT345 Okęcie Delivery readability five.
¶ Additional Information
For more information use:
- Manual of Radiotelephony Document 9432
- Quick reference guide to phraseology.
Should you have any questions, our staff members are always happy to help you.