Helicopter radio proceedures
Listen before you call – Someone else may be using the channel. If more than one station is transmitting at the same time, garbled transmission will result.
Speak clearly – Use your normal voice and do not speak too fast. Have the microphone close to your mouth but test so as to not cause distortion.
Think before you speak – Know what you are going to say before you press the microphone switch. Divide your message into natural phrases instead of individual words so that it flows smoothly.
Spelling – Spell difficult, ambiguous or unfamiliar words – using the phonetic alphabet if necessary.
Station to Station Transmissions – Communications between stations should be restricted to official messages or those of an emergency nature only.
Short Conversation – Do not wafle. Conversations should be kept as brief and accurate as possible allowing others time to use the frequency.
Prompt Replies – When called, or when a transmitting station has said "over", reply immediately. When a transmitting station fails to receive an immediate reply, there is doubt as to whether;
i. the message is received
ii. the radio is working
iii. the operator is still at the radio.
It is essential that everyone listening on radio frequencies is in no doubt as to who is talking to whom.
The callsign of the station contacted is always to be used BEFORE that of the transmitting station, even in an emergency it would start "all stations"...this is... declaring an emergency.....
| Phrases: The following list and explanations explain most of the common phrases which may be used in message texts; | |
| Phrase | Explanation |
| "RADIO CHECK" | Request a report on reception of the transmission at your location. |
| "SAY AGAIN ALL AFTER" | A request for the sender to re-transmit all of the transmission after a particular word of phrase. |
| "I SPELL" | Means that the next word will be spelled out. In poor conditions, phonetics will be used. |
| "NO DUFF" | May be used during an exercise to indicate that this is not an exercise message. A genuine message. |
| "NEGATIVE" | Means NO – more distinctly. |
| "AFFIRMATIVE" | Means YES – more distinctly |
| "I SAY AGAIN" | A repeated word or phrase or a correction. |
| "FIGURES" | The following part of the text in numerals. |
| "MESSAGE CORRECT" | The read-back was correct. |
| "READ BACK" | The message just sent will be re-transmitted for clarity. |
| "STOP" | Indicates a FULL STOP punctuation mark in the message. |
Procedures
"This is" should be used as to separate the callsign of the station being called from the callsign of the calling station.
"OVER" or "OUT". When a transmission has not ended with either "OVER" or "OUT", delays and misunderstandings can result. A receiving station would have no indication that the transmitting station has said all that it wants to say unless one of these words is used.
When "OUT" is not used to complete a series of transmissions, either stations on the frequency will have no clear indication that the frequency is free for other users.
OVER means" I have finished transmitting" – "please go ahead with your reply."
"OUT" means " This conversation is ended " – the frequency is now free for other users. These definitions indicate that the phrase "OVER AND OUT" is contradictory and should not be used.
| Proceedure Word (Prowords | |
| Prowords are standard, easily pronounced words which have been assigned special meanings to speed up messages handling on radio networks. They should be used whenever appropriate.
A proword, or combination of prowords must never be substituted for any word or phrase in the text of a message. The following prowords are acceptable for general use: |
|
| Phrase | Explanation |
| "ACKNOWLEDGE" | Receipt of this message must be acknowledge by the addressee. (The person to whom it is addressed) |
| "ALL BEFORE/AFTER" | Used when asking to repeat that portion of a message preceding or following a key word of the text. |
| "CORRECTION" | Indicates that an error has been made and that the transmission will continue from the last word correctly used. |
| "DISREGARD THIS" | This transmission has been made in error – TRANSMISSION" disregard. |
| "FIGURES" | Numerals follow. |
| "FROM" | Originator of the message is .......................... |
| "I SAY AGAIN" | I will re-transmit the message or part message. |
| "I SPELL" | The next word will be spelled. In poor conditions, use phonetics. |
| "RELAY TO" | Transmit this message to the addressee indicated. |
| "ROGER" | Message received and understood. |
| "ROGER SO FAR" | (query) Have you received my message so far? (answer) Message received so far – carry on. |
| "SAY AGAIN" | Re-transmit all (or all after ) your transmission. |
| "WAIT" | I am pausing for a few seconds. |
| "WAIT OUT" | I will call you again – a pause for longer that a few seconds. |
| "WILCO" | I Will Comply with your message ( to be used only by the person who intends to comply) |
