Airborne Equipment
Course Index
Unreliable Signal Flag
CDI Needle
Omni Bearing Selector Knob TO/FROM Indicator 2o dots
VOR INDICATOR
Each dot is 2 degrees off course •5 dots sensitivity ; 10 degrees full-scale deflection
Radio Navigation:
VOR
Very High Frequency Omni-directional Range
VOR Navigation
Very High Frequency Omnidirectional Range (VOR)
Most common ground based navaid
Check TO-FROM window “TO”- selected course will take you generally
TO station “FROM”- selected course will take you generally FROM station
Identifying a Station
VOR VORTAC VOR/DME
108.00-117.95 MHz
VHF frequencies have “line of sight” limitation
VOR stations transmit radio beams, or Radials, which radiate outward FROM the station in every direction, like spokes on a wheel
Aircraft is located AWAY from needle Needle represents selected course line
Each dot is 2 degrees off course
5 dot sensitivity: 10 degrees full-scale deflection
Low Altitude VOR
40 n.m. 1,000 AGL - 18,000 AGL at altitudes > 18,000 AGL possible interference
High Altitude VOR
40 n.m. 1,000AGL- 14,500 AGL 100 n.m. 14,500 AGL - 18,000 AGL 130 n.m. 18,000 AGL – 45,000AGL 100 n.m FL 450 - FL 600
VOR – BASIC OPERATION
VOR GROUND STATION
IABLE SIGNAL
VOR – BASIC OPERATION
IN PHASE: REFERENCE-VARIABLE SIGNAL (360) OUT OF PHASE: VARIABLE SIGNAL (090) OUT OF PHASE: VARIABLE SIGNAL (180) OUT OF PHASE: VARIABLE SIGNAL (360-000)
CONE OF CONFUSION: over the station
ZONE OF AMBIGUITY: “ABEAM” the station The VOR will indicate “OFF” or “NAV” flag indications when over or abeam the station or when out of range and not receiving a reliable signal.
Station Passage
Close to the station Cone of confusion
VOR CLASSES/Standard Service Volumes
VOR classification in A/FD “radio aids to navigation”
AIM 1-1-8
Terminal VOR
Located at Airports for instrument approaches 25 n.m. 1,000AGL- 12,000 AGL
Pull “Volume/Ident” knob Listen to Morse Code Identifier Compare it to desired station on chart Wrong code - Wrong station No code - No station “TEST” ( _ . … _ ) code - Station under maintenance VOR code: approx. every 10 seconds DME code: approx. every 30 seconds
VOR RADIALS
VOR RADIALS vs. VOR COURSES
Navigation Procedures
Tune: select frequency Identify: listen to Morse code signal Navigate:
Select desired course on OBS Center needle to determine location
Interpreting VOR Indications
Needle centered with “FROM” in window
Aircraft is on radial OBS course Needle centered with “TO” in window Aircraft is on radial reciprocal to OBS course “FROM TOP - TO BOTTOM” Needle NOT centered (L or R of center)