Communication Flashcards
What frequency is VHF?
30-300MHz
What frequency is HF?
3-30MHz
What is the used VHF frequencies and what do they do?
108-137 used (others for radio systems)
108-118 Navigation
118-137 Communication
What’s the spacing between VHF channels?
8.33KHz
What are antennas 2 functions?
-transmit
-receive
What is modulation & demodulation in Simple’s terms?
Basically encryption onto a carrier frequency
How many VHF radios are there and what is the last one used for?
3
Last used for ACARS but can also be used for comms
What does an Ariel tuning unit do?
Controls Ariel length electrically
What frequency is the emergency location transmitter?
121.5
What is selcal?
Selective calling
What does selcal do and how does it do it?
Filters out unnecessary information by using codes to identify what’s meant for who using 4 digits
What does satcom normally replace?
HF
What is ACARS?
Aircraft Communication Addressing & Reporting System
Name 3 things the FDR is required to record?
-engine status
-flight control status
-system status
-timescale-usually in seconds
-compass heading
-pressure altitude
-airspeed
-vertical acceleration
-PTT transmit marker to synchronise with ATC & voice recorder
How long does the underwater locator beacon transmit for?
90 days
