Module 9-10-11-12 Flashcards
The VOR (VHF Omni-directional Range) system ranges between which frequencies?
108.00 to 117.95
There are two phase signals broadcasting from a VOR ground station. What are they?
Reference phase & Variable phase broadcasting
3 things that could indicate a flag showing on a CDI?
Not tuned to the right station
The station is too far away
Could be missing the reference or variable signals
What does CDI stand for?
Course Direction Indicator
What does RMI stand for?
Radio Magnetic Indicator
Where does the indicator always point to on an RMI?
Always points towards the station
What does the HSI represent?
(Horizontal situation indicator) Shows a TO/FROM indicator
Shows a deviation line in the middle showing how on or off course the aircraft is
Testing procedure for the VOR system
Power up aircraft (AC and DC)
Avionics MAster On
Unit of testing turned on
Dial in 108.00 test frequency
Check VOR audio, select NAV for tone output
Check for flags pulling or dropping into view
Check needle deflection +- 20 degrees
Check TO/FROM indicators
Check needle centering accuracy +- 3 degrees
Frequency Range for a DME? (Distance measuring equipment) (NAV)
960 MHz to 1215 MHz
The ground station sends out ________
Squitter pulses
The aircraft DME starts to transmit in search mode called_________
Jitter
The total time it takes for an RF signal to travel from a ground station to an aircraft and back is ___________
12.36 microseconds
What does ADF stand for?
Automatic Direction Finder
What is the ADF used for?
To find the aircrafts bearing
What is the frequency range for ADF?
190 kHz to 1750 kHz
An ADF with a fixed compass card can only indicate__________ bearing to an NDB
To/Forward
What is the purpose of an ADF sense antenna?
Adds an omnidirectional pattern to the signal, eliminating the null with the loop antenna
How can the sense antenna be selected by the pilot?
Using the Ant-Rec button, turning off the loop antenna, which allows listening only
What is the funtion of the switch marked BFO or TONE?
Causes the incoming frequency to “beat” against the BFO. The difference comes out as audible morse code
In addition to distance-to-station, an airborne DME computes_______and_________
Time-to-station & groundspeed
All aircraft interrogating the same DME greound station are all the same frequency. How does an aircraft identify its replies from all others?
If the aircraft detects the same signal coming back as the one it sends out to the station
How is a DME station tuned in?
If the aircraft sends an interrogation signal to the grounbd station, and then sends back a reply to the aircraft
What happens when more than 100 aircraft interrogate the same DME ground station?
To avoid overload, the station reduces its receiver sensitivity, by excluding more distant aircraft
Why does the DME ground station delay its reply by 50 microseconds?
To give the station time to receive the pulses from the aircraft and verify it is the correct one before sending a reply
The VOR reference phase broadcasts in what direction?
All directions (omni-directional)
The VOR variable phase rotates _________a second
30 times
HOw does an aircraft VOR receiver know its bearing form a gorund station?
The difference between the variable and the reference phases determines the bearing
The 2 tones broadcasted on a localizer are
90 Hz and 150 Hz
What component of an ILS (Instrument Landing System) provides an extended centerline to the runway?
Localizer
What component of an ILS provides vertical guidance to a runway?
Glideslope
How are glideslope receiver frequencies selected?
Choosing the right frequency on the VOR in the cockpit
How many satellites are there in a GPS constellation?
24 Satellites
Name the 3 segments of a GPS system
Space segment
Control segment
User segment
Localizer uses the ______ frequency band and the glideslope uses the _________frequency band
VHF - Localizer
UHF - Glideslope
What frequencies does the ILS system use?
108.10 to 111.950
What system does an RMI NOT display?
The ILS system
What must be required in order for an ILS flag to pull?
Both the 90 Hz and 150 Hz signals
What does the DGPS (Differential GPS) do?
Greatly increases the accuracy of the GPS system
What does LAAS stand for and where is it typically used?
Local area augmentation system is usually installed around airports for greater accuracy
2 parts of an ATC Transponder System
Primary Surveillance Radar
Secondary Surveillance Radar
What frequency range is used for the primary radar?
1250 MHz to 1350 MHz
What frequency range is used for secondary radar?
1030 MHz to 1090 MHz
From a ground station, 1030 MHz is for ___________ and the 1090 MHz is for ____________
1030 - Receiving
1090 - Transmitting
From an aircraft transponder system, the 1030 MHz is for ___________ and the 1090 MHz is for _____________
1030 - Replying
1090 - Transmitting
What is side lobe suppression in an ATC Transponder signal?
The suppression in a signal which the side lobes broadcasting from a ground station send out unintentional interrogations to aircraft, which the signal ignores. Otherwise the aircraft will blip in the wrong location
In ALTITUDE mode on a transponder box in the cockpit, what signal will it send out?
BOTH squawk code and Altitude
What is the Pulse order for a transponder signal?
FRAME C1 A1 C2 A2 C4 A4 blank B1 D1 B2 D2 B4 D4 FRAME
Special IDENT signal (if turned on)
What wave propagation is used for Transponders?
Direct wave propagation - Line of sight
How do weather radar work and what are they used for?
They send out radio waves and those waves reflect off of target such as clouds, thunderstorms, rain, etc.
Also used to help avoid extreme weather
Weather radar safety - What must we be aware of when testing weather radar?
Do not operate during fueling processes
Circuit breakers are turned off
Do not operate in the hangar
Do not operate when personnel are within 50 feet in front of it
Radar altimeter works at a maximum of __________ (height)
2500 ft AGL
Frequency range for Radar Altimeter?
4.25 GHz to 4.35 GHz
