Aim
To be able to use radio navigation while flying
Application
Cross country navigation
Orientation of your position
Reduction of work load
Preparation for I.R.
VOR Theory
o short range, in a straight line
o Has a 360 deg signal
o Waves, signals, ground equipment
Cone of Confusion
If very near the station gets too sensitive
Zone of Ambiguity
Cross hatch flag / indication will change TO/FROM at exactly 90o from your course (abeam VOR station)
Equipment Testing
Ground Tolerance
4 deg
Equipment Testing
Inflight Tolerance
6 deg
VOR Test Procedure
T – Tune to the VOR frequency
I – Identify (VOR Morse code id)
T – Test to find your line of position (LOP)
Test VOR
A – Accuracy LOP +/-4o or 2 dots (ground); +/-6o (in flight)
S – Sensitivity == + & - 10o from your LOP, CDI should have full deflection
A – Ambiguity == + & - 90o from your LOP, Cross hatch / indication must change
Position Orientation
To find Radial (LOP)
- Center CDI
- Flag should read FROM (go away)
- Course Index = radial
Homing
1) Center CDI / TO indication
2) Look at C.I.
3) Turn to HDG of C.I.
Tracking
Bracketing
Technique used to determine the optimal heading to maintain course especially when wind is a factor
Tracking
Reverse Sensing
occurs when CDI needle indicates the opposite of what you expect
check indication of going 90 deg
Interception
to know where you are and to where you want to be. Rotate OBS to desired course/radial.
Interception
Inbound
set CDI to the radials’ reciprocal and twist to the desired course to the station with a TO indication.
Interception
Outbound
twist and center the CDI to the desired radial with a FROM indication
Consideration when intercepting
Deviation
Distance
Speed of the airplane
Distance check without DME
- Center CDI, take note of CDI
- Fly a heading +/- 90 deg
- Time for 1 minute
- Center CDI, take note of the new CDI
Formula: Distance to Station = TAS / Deg. Displaced
Time to station = 60 / Deg. Displaced
