Radio Navigation Flashcards
What is the frequency range that VOR transmitters may be in?
108-117.95
VOR is an abbreviation for what?
Very high frequency Omni directional Range
When first built, VOR ground transmitters are aligned with what?
Magnetic north
How many radials does a VOR transmitter have?
360
How do VORs work?
Directional signal - rotates at 1800 RPM
Reference signal - Omni directional, emitted when variable signal is at magnetic north
Receiver measures phase shift between the 2 signals
What is the service volume of a high altitude VOR?
1,000-14,500’ 40 nm radius
14,500-18,000’ 100 nm radius
18,000-45,000’ 130 nm radius
45,000-60,000’ 100 nm radius
Where can a pilot look up a VOR to see if it is a high altitude, low altitude, or terminal VOR?
A/FD
What is the service volume of a low altitude VOR?
1,000-18,000’ 40 nm radius
What is the service volume of a terminal VOR?
1,000-12,000’ 25 nm radius
Where can a pilot look up VOR unreliable areas?
A/FD
Can VOR signals generally be received by an aircraft when the aircraft is below 1,000’ AGL?
Yes, as long as no terrain gets in the way
CDI is an abbreviation for what?
Course Deviation Indicator
Each dot on the CDI scale equals how many radials off?
2 degrees
What does it mean when the red nav flag shows on a VOR CDI?
Something is wrong
You can’t use it for navigation anymore
OBS is an abbreviation for what?
Omni Bearing Selector
A pilot has just tuned in a VOR transmitter. What must the pilot then do to determine if the VOR transmitter is reliable?
Listen for correct station identifier (morse code)
In addition to the morse code identifier being transmitted, what 2 additional types of information might come from a VOR?
Hiwas
FSS
To avoid reverse sensing when using a VOR, a pilot must follow what 2 techniques?
OBS must match heading
Top of VOR/HSI will take me To the VOR station
What does it mean when the HDG red flag on an HSI is showing?
Compass warning flag
Where is the VOR come of confusion?
Area directly over the VOR
What does the CDI needle, NAV flag, and TO/FROM flag do when flying across the cone of confusion above a VOR transmitter?
Erratic needle
Nav flag may come on
TO/FROM flag will switch back and forth or disappear completely
How does a pilot know that they have finished crossing over a VOR?
TO/FROM flag flip
Where is the zone of ambiguity on a VOR? What will the to/from flag do when in the zone of ambiguity?
Area 90 degrees to either side of selected course
To/from flag unclear
What does line of sight mean?
That radio waves do NOT bend around mountains
DME is an abbreviation for what?
Distance Measuring Equipment
DME transmitters are typically located at what 2 types of places?
At many VORs
On some airports
Which component in a DME system sends the first signal?
The aircraft
DME equipment in the aircraft shows what information?
NM from the station
DME distance is measured as what?
Slant range
Will DME radio waves bend around mountains?
No
What 2 types of VORs have DME?
VOR DME and VORTACs
Do some instrument approaches require DME?
Yes
When flying IFR what 2 requirements must be met for GPS distance to be used instead of DME?
IFR certified GPS
Database so up to date
In the transponder system, what piece of equipment sends out the first interrogation signal?
Ground station
Most ATC radar antennas rotate once every how many seconds?
12 seconds
On a transponder, what does it mean when the REPLY light illuminates?
When you get hit by an interrogation signal
When a pilot pushes the IDENT button on a transponder, what happens on the ATC radar screen?
Your reply will be brighter than everyone else’s
Mode A has what type of information transmitted?
Squawk codes
Transponder signal
Mode C has what type of information transmitted?
Squawk codes
Altitude
If mode C transmits pressure altitude, how do ATC controllers know what true altitude an aircraft is flying?
ATC computers plug in the altimeter setting to fix to true altitude
Do transponder signals bend around mountains?
No
GPS is an abbreviation for what?
Global Positioning System
How many satellites are in the GPS system?
24
How many satellites must be received in order to get 2 dimensional navigation?
3
How many satellites must be received in order to get 3 dimensional navigation?
4
What does 3 dimensional GPS navigation include?
Latitude
Longitude
Altitude
How many satellites must be received in order to get RAIM?
5
RAIM is an abbreviation for what?
Receiver Autonomous Integrity Monitoring
What is RAIM?
The GPS receiver is determining if it can navigate accurately
WAAS is an abbreviation for what?
Wide Area Augmentation System
What does WAAS do for enabled receivers?
Improves accuracy, integrity and availability of GPS signals
What are the 3 sensitivity modes for GPS navigation WITHOUT WAAS, and what is full scale deflection for each mode?
En route - 5 nm
Terminal - 1 nm
Approach - 0.3 nm
What are the 3 sensitivity modes for GPS navigation WITH WAAS, and what is full scale deflection for each mode?
En route - 2 nm
Terminal - 1 nm
Approach - <0.3 nm
Do fly over GPS waypoints have to be crossed over before turning?
Yes
Do fly by GPS waypoints have to be crossed over before turning?
No
What are the 3 distinct functional elements that make up GPS?
Space
Control
User
How much can helicopter rotor speeds cause the VOR CDI to fluctuate?
+- 6 degrees
Who uses TACANS?
Military
Naval forces
What 2 components make up a VORTAC?
VOR & TACAN
How can a pilot know a NAVAID is undergoing maintenance?
The code identification is removed
What is the accuracy of DME while within 199 nm?
Reliable signals may be received with an accuracy of better than 1/2 mile or 3% of the distance
Aircraft using GPS navigation under IFR must also be equipped with what?
An approved and operational alternate means of navigation appropriate to the flight
