Basic concepts Flashcards
1
Q
Radio waves
A
is an electromagnetic transmission
2
Q
Categories of radio waves
A
Low Frequency
High Frequency
3
Q
Low frequency
A
Long Wavelength
Low Energy
Poor Quality
KHZ
1000 cycles of radio waves
4
Q
High frequency
A
Short Wavelength
High Energy
Good Quality
MHZ
5
Q
What frequency band limit is used during flight?
A
VHF - Very high frequency
6
Q
VHF band limit
A
30-300 MHZ
7
Q
VHF Characteristics
A
- Line of sight and short range. Greatly affected by the following
-Transmission power of both aircraft and ground station
-Height of transmitter and receiver
-Obstacles at or near the transmission site
-Obstructions between aircraft and ground station
8
Q
Transponder modes
A
Mode A
Mode C
9
Q
Transponder
A
a device that receives a radio signal
and sends out a signal in response
10
Q
Mode A
A
sends out the Identification (Squawk) only
11
Q
Mode C
A
sends out the Identification (Squawk) and altitude (Pressure Altitude)
12
Q
Transponder squawk
A
- “squawk” – assigning a transponder code
- Emergency squawk codes
- Right to left
- 0 - 7
13
Q
Emergency locator transmitter (ELT)
A
- self-contained
- self-powered
- Automatic on impact (5G’s)
- Battery should be enough to power it for at least 48 hours
- Batteries should be changed or recharged at 50 percent of the battery’s useful life
14
Q
ELT distress frequencies
A
121.5 MHz (civilian)
406 MHz for new ELTS
243 MHz (military)
