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
