Course 7 - Section 20 - ATS Communication Flashcards
Frequency Management
Co-Channels
VHF radio waves can only be received within line of sight
Due to the curvature of the earth, it is possible to reuse the same frequency (co-channel) provided that the geographical locations are sufficiently separated to prevent interference
Frequency Management
Frequency Protected Service Volume
Frequency protected service volume ensures that radio frequency is used to service a specific volume of airspace and is protected from co-channel (same frequency) and adjacent channel interference
agreements regarding the volume of airspace (such as sector, control zone etc) establish the allocation and reallocation of frequencies in a safe and effective manner
***Radio frequency assignments based on FPSV increase the reuse portential of ATC radio channels
Frequency Management
Peripheral Air-Ground Links (PALs)
Peripheral stations or peripheral air-ground links (PALs) are remote transmitters and receivers placed at various locations throughout the country.
THEY ALLOW DIRECT COMMUNICATIONS (DC) WITH AIRCRAFT
PALs are shown in the Canada Flight Supplement , as well as on LO and HI charts
Manual of Air Traffic Services (MATS) rule regarding receiver volume levels
A general rule is to set a receiver at a volume that can be heard at a particular station, but not two stations away. When there are multiple frequencies at a position, select only those that are required
The rules also state that you should only select transmit mode on the frequencies required to maintain communication with traffic in your area of responsibility
To avoid misunderstandings and to ensure communications remain professional, follow these guidelines:
Manual of Air Traffic Services (MATS) provides controllers and FSS with techniques to ensure communications are conducted properly.
Here are some of them
Controllers and FSS may only use authorized communication techniques.
Using standard phraseology ensures……
Radio Readability scale
- Unreadable
- Readable now and then
- Readable but with difficulty
- Readable
- Perfectly readable
Direct Communications
Direct communications (DC) refers to pilots and ATS personnel speaking directly to each other without relaying through another unit
Reasons for Loss of direct communications (DC) availability
(List and describe)
- Inflight communication failure
- aircraft loses capability to transmit
- aircraft loses capability to receive
- The mic is stuck (someone sitting on transmit button) - ATS Communication Failure
This could be a transmitter stops working or as simple as your headset not being plugged in - Aircraft out of range
- Other reasons
- complete radio failure
- an emergency
- a hijacking
Secondary Communication Options
(List)
You have 4 options if direct communications is not available:
- Other ATS units
- Other Aircraft
- Airlines
- Other Agencies
Secondary Communication Options
Other ATS Units (List)
- Towers or ACCs
- Flight Service Stations
- Flight Information Centres
Secondary Communications Options
Other ATS Units
Towers or ACCs
Towers or ACCs
- Can receive or pass position reports for aircraft not capable of communicating with a controller
- May be used to relay clearances and instructions to aircraft operating within their radio range
Secondary Communications Options
Other ATS Units
Flight Service Stations
Flight Service Stations
- ARE THE PRIMARY UNIT USED TO COMMUNICATE WITH AIRCRAFT WHEN TOWERS OR ACC UNITS ARE UNAVAILABLE; they can perform the same communication services as towers or ACCs
- Are more numerous across Canada than towers or ACCs, giving them very good radio coverage
- Have access to VHF, UHF, and SELCAL, and are the prime radio link in remote areas
Secondary Communications Options
Other ATS Units
Flight Information Centres
Flight Information Centres
- Monitor multiple enroute frequencies covering a wide geographical area
- perform the same communications services as ACCs or towers
- are frequently used to regain contact or to relay information to aircraft
Secondary Communications Options
Other Aircraft
Other aircraft may be helpful. They can act as a relay between aircraft that are too low or too distant to receive ATS transmissions or in cases where communication is lost for other reasons
Secondary Communications Options
Airlines
Airlines can be used to establish communications. They are helpful because they track their aircraft and they use specific company frequencies
Secondary Communications Options
Other Agencies (List and describe)
- Police and meteorological offices
- are useful in remote areas
- often use a teletype network - Telephone Companies
- Use satellite telephone systems that can reach remote areas - Department of National Defence
- has an extremely comprehensive communication and radar network
- has special abilities in remote areas
- is willing to provide assistance, as well as search and rescue services - Canadian Coast Guard
- Is available in the eastern and western coastal regions, the arctic, as well as great lakes
- is involved in water related search and rescue activies
MATS tells us that normally, you should transmit ATC messages via one of the following communications systems:
ATC Interphone
- For IFR and CVFR movement and control messages.
Air-Ground
- For messages to aircraft concerning control and safety of flight
MATS states that if primary communications systems are congested or not available, you may use an alternate communication system:
- Transmit IFR and CVFR movement and control messages using the quickest method. When appropriate for the provision of air traffic services, you may place or accept long distance telephone calls
- You may transmit VFR and DVFR movement messages that require immediate action via ATC interphone
Interphone Communications have two primary systems : (List)
ATC Interphone (IFR and CVFR movement and control)
AMIS Interphone (DVFR and VFR movement messages)
ATC Interphone
The ATC interphone system is DESIGNED TO EXCHANGE IFR AND CVFR AIR TRAFFIC CONTROL MESSAGES
ATC INTERPHONE SHOULD ONLY BE USED TO TRANSMIT MESSAGES FOR THE PROVISION OF AIR TRAFFIC SERVICES (no personal communications etc)
The system has two primary modes of operation: telephone (land line) and hotlines
The telephone mode works as much as a normal phone does and must be answered by the controller when it rings
ATC Interphone Hotlines
Hotlines link two units directly and allow for immediate, direct communication. Normally, only brief control messages with a high level of immediacy are transmitted via hotlines
eg. A hotline that connects moncton tower to moncton ACC may be used exclusively by the controllers in those two units
ATC Interphone Priorities
AMIS Interphone Priorities
How to place a call: When sharing lines
(List)
When sharing lines you will use MANUAL SIGNALLING or VOICE SIGNALLING
Most internal ATS telephone lines have the capability to dial a specific sector or unit directly
However, some telephone lines are shared between sectors or units.
How to place a call
Manual Signalling
Manual Signalling is completed using either a push button, a key, or a dial that, when operated, actuates a signalling device at the office called
Follow three steps:
- Ensure that the line is free by asking “LINE CLEAR”?
- Key in a three digit code to connect to the appropriate unit or sector
[the unit answers by identfiying themselves]
- Identify yourself and state your reason for calling
How to place a call
Voice Signalling
Voice signalling is accomplished by speaking into the handset microphone. The call is heard through loudspeakers in all offices so equipped on that circuit
Follow three steps:
- Ensure that the line is free by asking “LINE CLEAR”?
- Identify yourself and speak the name of the desired unit or sector
[the unit answers by identfiying themselves]
- Identify yourself and state your reason for calling
*Voice signalling is not often used by ATS units
How to place a call
Higher priority messages (shared telephone line)
There may be occasions where a shared telephone line is in use, but someone else needs access to the line to TRANSMIT A HIGHER PRIORITY MESSAGE
To interrupt a transmission, use the words EMERGENCY or CONTROL
Note that ACC controllers have operational jurisdiction and it is their role to resolve any questions of priority
How to place a call
Determining Relative Importance, voice signalling
There are procedures for determining relative importance of messages specific to voice signalling
When someone answers the call, indicate the type of message being transmitted to help the answering station determine the relative importance of the message
You may use expressions such as EMERGENCY, CONTROL, CLEARANCE, ARRIVAL REPORT, and CALL BACK WHEN POSSIBLE
How to place a call
Terminating a call
When terminating a call, make sure the circuit is disconnected
Note that circuits may be connected manually by an operator at the communications station or automatically by dialing a “connect” sequence
Transborder Circuits
Certain ATS facilities have circuits that connect with counterparts in other countries
When communicating with foreign agencies, use the same rules as when communicating with Canadian ATS staff
Hotline Protocol
When using hotlines, follow these steps:
- State the name of the sector or unit you are calling, followed by your own sector or unit name and the reason for the call
[The sector or unit being called answers by identifying themselves[
- State your message
Datalink Communication
Data link communication allows for message, requests, and ATC clearances to be displayed both to pilots and air traffic controllers in text form
IT ENHANCES THE RELIABILITY AND EFFICIENCY of communications between pilots and controllers
Data link communication infrastructure includes:
- VHF data links
- Satellite communications
VHF Data Links
VHF data links are widely used for aircraft operations, as well as for communicating limited flight information and some air traffic services, such as pre-departure clearances, ATIS information, altimeter information and runway assignments
Graphical weather service provides weather graphics information derived from ground-based weather radar
The information is then displayed on a cockpit control and display unit
Satellite Communications
Satellite communication (or SATCOM) is used for communications in the oceanic environment, such as in Gander ACC, and in remote, northern parts of Canada.
SATCOM behaves in much the same way as a telephone. A direct link is established between the controller and the aircraft. SATCOM transmits signals from earth to the geostationary satellite that receives, amplifies, and relays the signals back down to Eartch.
It is a power form of voice communication that can cover far more distance and a much wider area than most other radio technologies
