Communications Flashcards
(139 cards)
VFR Frequency Range
118.000 to 137.000 MHz (exclusive of 137.000)
Current VHF frequency spacing
Previous VHF frequency spacing
# channels
New: 8.33kHz
Old: 25kHz
# channels: 2280 up from 760
Rounding VHF frequencies to channels
Round to final figure of 0 or 5
Pronunciation of decimal frequencies
If frequency ends ###.#00 only pronounce first DP
Otherwise pronounce all DP
(e.g. one two three decimal four, or one two three decimal four five zero)
Max distance at which to contact ATSU
- International airport
- Other aerodrome
- Safteycom
International airport - 25nm
Other aerodrome - 10nm
Safetycom - 10nm
Max height at which to contact ATSU
- International airport
- Other aerodrome
- Safteycom
International airport - 10,000ft
Other aerodrome - 3,000ft max (ideally 1,000ft)
Safetycom - 2,000ft
[All aal]
Emergency Frequency
121.5
2 types of VHF-NAV equipment
VOR - VHF omnidirectional range
ILS - Instrument Landing System
2 types of NAV equipment excl VHF NAV
DME - Distance Measuring Equipment
ADF - Automatic Direction Finder
Radio frequency range used by NAV equipment
108-118MHz
How do transponders work
Detects signal from SSR (Secondary Surveillance Radar) and reflects back boosted signal with additional info
TCAS
- Stands for
- Description
Traffic Collision Avoidance System
Uses Mode S transponder data to give traffic avoidance instructions to pilots
DAP
- Stands for
- Description
Downloaded Aircraft Parameters
An additional set of aircraft data sent by mode S transponders such as heading, airspeed, vertical rate, ground speed, true track angle etc.
TIS
- Stands for
- Description
Traffic Information System
Information gathered from nearby mode S transponders sent back to a mode S transponder unit and displayed to pilot for collision avoidance help
TIS
- How it works
- Aircraft range
A TIS equipped SSR will send information to a mode S transponder about the closest aircraft within 6nm and 3,500ft.
Information is displayed on a unit to the pilot and colour coded
TIS
- Limitations
- Only closest 8 aircraft displayed
- No avoidance action given, for information only
- Only available on approach radar stations (i.e. near large airfields), not enroute
- Must be within 50nm to receive info
How does TCAS work?
TCAS reads transponder signals from nearby aircraft and gives collision avoidance guidance to the pilot.
Frequency Monitoring Code
This is a squawk code you use to indicate that you are monitoring a particular radio frequency in a given chart area
CAVOK
- Short for
- Definition
Ceiling and Visibility ok
- Visibility > 10km
- No cloud below 5,000ft aal or below minimum sector altitude & no cumulonimbus clouds
- no precipitation reaching ground, thunderstorms, shallow fog or low drifting snow
Relationship between UTC, Zulu time and GMT
They are all the same time
Which numbers are never abbreviated (e.g. hundreds, thousands)?
- Time
- Altimeter settings
- Transponder codes
- Runway #
- Headings
- Callsign digits
- Radio frequencies
- Wind direction/speed
3 types of radio message from ATSU
Clearance - Only issued by ATC, must be followed and read back in full
Instruction - Should be followed if safe to do so. Ideally read back.
Information - Don’t read back (e.g. wind)
Readability ratings
Strength:
5 - perfect
1 - unreadable
5 key aerodrome and circuit r/t positions
1) Parked - Departure info, taxi.
2) Holding - ATC route clearance, ready for departure
3) Downwind
4) Final - Cleared to land/land @ your discretion
5) Runway vacated