VHF Radios for Mountain Use

VHF Radios for Mountain Use
April 18, 2015 Webmaster

The following description is based on standard radio communication for VFR flying. Back-country radio communication does not require the same standards as a pilot communicating with air traffic controllers or other pilots, but the systems and procedures developed for VFR flight are well tested, an attempt at documentation was made, and there are many similarities between the requirements for pilots and back-country leaders. In particular, aviation emergency procedures, call-up procedures and position reports lend themselves well to back-country use.

Initiate Communication

To initiate a call use the following procedure:

  • Listen to the frequency to determine if there is any traffic. If the frequency is clear proceed.
  • Say ” this is”
  • Wait for a response, if no response is received, try again.

i.e. Tune your radio to 146.530 MHz and listen for 10-20 seconds for traffic. If the frequency is clear, say in your best pilot imitation:

“Stanely Mitchell Hut, this is Victor Alpha Six Alpha Brave Charlie”(replacing VA6ABC with your own call sign).

If you receive a response such as:

””Alpha Bravo Charlie this is Stanely Mitchell Hut, go ahead””

Contact has been initiated and communication can begin. The call-up procedure is useful because not everyone is minding their radio at all times. It may take the radio operator a few moments to get to their radio, stop skiing, take mitts off, before they can respond. Proceeding with anything important during the call-up is likely a waste of time unless the recipient is already minding their radio. In cases where a previous transmission was just heard, the call-up could be skipped, just make sure the previous transmission has ended.

Once contact has been made, there are a number of different types of calls that can be made:

  • Emergency – situation require immediate assistance.
  • Urgency – situation concerning safety that do not require immediate assistance.
  • Position reports – let a responsible person know where you are at a given point in time.
  • Change of trip plan – amend a trip plan with a responsible person such as change of destination or arrival time (i.e. inform responsible person that you are going to be late)
  • Transmission Check – verify quality of communication with another party.
  • Conditions reports – share weather, snow or avalanche conditions with other parties.
  • Miscellaneous – Other useful communication

Emergency Call

An emergency is defined as a condition of being threatened by serious or imminent danger and of requiring immediate assistance.
An Emergency call differs from a standard call in that the call-up and the message are run together and the entire message is repeated until contact is made. The basic format is:

  • Mayday, Mayday, Mayday
  • this is
  • Your call sign repeated three times (officially), often just said once
  • Your location
  • Problem and action
  • Your call sign
  • Over

This message is repeated on an interval such that there is enough time for a radio operator to respond. In the back-country, resources are limited and a quick response is often critical. Pilots are told “aviate then communicate” because it is often more important to handle the situation at hand than to try and communicate with the outside world.

An example transmission would read:

“Mayday, Mayday, Mayday this is Victor Alpha Six Alpha Brave Charlie”
“I’m at an elevation of two four five zero meters on Christiana Ridge”
“Three skiers have been caught in an avalanche, two skiers are searching”
“Victor Alpha Six Alpha Brave Charlie”
“Over”

Urgency Call

An urgency call is made when there is a condition concerning the safety of a party, or of another party, but which does not require immediate assistance. An urgency call is made in much the same way as an emergency call, but the word “Pan Pan” is used in place of “Mayday”.

An example transmission would read:

“Pan Pan, Pan Pan, Pan Pan, this is Victor Alpha Six Alpha Brave Charlie”
“I’m am lost on the Columbia Icefields Neve, white out conditions”
“Group of 4 with 1 days worth of food and fuel left”
“Victor Alpha Six Alpha Brave Charlie”
“Over”

Position Reports

Position reports are most useful when a trip plan has been filed with a responsible person within radio communication. Often times, big ACC groups will require radio communication with other groups or camp manager at regular intervals. A position report should be initiated by a call-up followed by, you guessed it, your position.

An example position report would read:

“Stanely Mitchell Hut this is Victor Alpha Six Alpha Brave Charlie”
“Victor Alpha Six Alpha Brave Charlie this is Stanely Mitchell Hut go ahead”
“Stanely Mitchell Hut I’m at an elevation of two four five zero meters on Christiana Ridge, descending.”
“Roger”

Plan Change

When a trip plan has been filed with a responsible person, it is important to keep the plan up-to-date. Changes in ETA, destination or route should be communicated if possible.

An example position report would read:

“Stanely Mitchell Hut this is Victor Alpha Six Alpha Brave Charlie”
””Victor Alpha Six Alpha Brave Charlie this is Stanely Mitchell Hut go ahead””
“ETA at the hut of seventeen thirty, correction eighteen hundred”
””Roger””

Transmission Check

VHF radios are a line of sight communication device. Distances of 100 km or more are possible, but quality can suffer. It is often worth checking the quality of a transmission.
There are a number of different scales, but the HAM scale is a readability scale out of 5 and a strength scale out of 10.

The readability scale is defined as:

  1. unreadable
  2. inconsistently readable
  3. readable with difficulty
  4. readable
  5. perfectly readable

The strength scale is 1 for very weak to 10 excellent. In many cases, the radio will have strength scale in the display making it easy to tell.

A typical transmission would read:

“Stanley Mitchell Hut this is Victor Alpha Six Alpha Bravo Charlie, how do I read”
“Alpha Bravo Charlie, you read five by ten”
“Alpha Bravo Charlie”

Conditions Report

An

Miscellaneous Call

An
A typical aviation procedure call

Procedural Matters

Numbers

Typically, numbers are spoken from 0-9 from left to right and the decimal is spoken as “decimal”. To communicate 101.3, one would say “one zero one decimal three”. In many cases, 1500 is said often said “fifteen hundred”, breaking the rule, but much easier to say.

Common Words and Phrases

PhraseTranslation
AcknowledgeLet me know if you have received and understood this message.
AffirmativeYes
NegativeNo
ConfirmPlease verify following message.
CorrectionI have made a mistake, the correct message is ...
Do you read?I am trying to make contact and have been unable, respond if you can hear me.
Say againPlease repeat previous message
How do you read me?What is the quality of my transmission by scale
OutTransmission is over, no response required
OverTransmission is over, expect reply
RogerI have received and understood your message
Stand byPlease monitor the frequency while I faff, I'll transmit again after a pause.

Phonetic Alphabet

The phonetic alphabet has been designed over many years to enable communication with poor reception. The phonetic alphabet may seem random, but that is the point, no two letter sound the same avoiding confusion. The phonetic alphabet is still in use today in aviation where all call-signs are communicated via the phonetic alphabet.

LetterPhonetic
AAlpha
BBravo
CCharlie
DDelta
EEcho
FFoxtrot
GGolf
HHotel
IIndia
JJuliet
KKilo
LLima
MMike
NNovember
OOscar
PPapa
QQuebec
RRomeo
SSierra
TTango
UUniform
VVictor
WWhiskey
XX-ray
YYanky
ZZebra
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