1. NAV 7
VOR and ADF

2. VOR

5. VOR Head TO/FROM indicator or sense indicator
Course Deviation Indicator or left/right needle or Track Bar Indicator
Omni Bearing selector
or Course selector

6. C172 INSTRUMENT PANEL

7. VHF Receiver

8. INSTRUMENT PANEL

11. VOT

12. COVERAGE - IF AT MRA, 50 NM - RECEPTION DISTANCE IS 1.23 x √ ALTITUDE

13. PRINCIPLES OF OPERATION Operation of the VOR is based on a phase difference between two signals – a reference phase and a variable phase. The reference phase, which is omni directional, radiates from the station in a circular pattern, the phase being constant throughout 360 degrees. The variable phase rotates uniformly at 1800 rpm causing its phase to vary at a constant rate.

14. Magnetic North is the reference datum for measuring the phase difference between the two signals. At Magnetic North, the two signals are exactly in phase. At other points around the compass, the phase difference varies accordingly. The aircraft equipment resolves the phase difference and displays it primarily in the form of angular displacement from Magnetic North as measured from the VOR station.

15. TRACK BAR DEFLECTIONS

18. VOR EQUIPMENT CHECKS

19. TRACKING AWAY FROM A STATION

20. TRACKING TO A STATION

21. VOR RELIABILITY
At the VOR facility, a monitoring system and two transmitters insure continuous reliable service. If the VOR signal is interrupted or the phasing is changed, the monitor system turns off defective equipment, turns on the stand-by transmitter, and excites an alarm at the remote control station. When a VOR is “on the air” while servicing is taking place, the station identification is removed.

23. FREQUENCY RANGES

24. ADF – Automatic Direction Finder

25. ADF – Automatic Direction Finder
Receiver tune and identify
LF/MF 2 or 3 letter Morse code
ILS locator 1 letter Morse code
Signal also powers bearing indicator
Antennae
Loop senses direction of station
Sense provides info if bearing to or from station
Bearing indicator
Points to station relative to nose or axis
Fixed card 0o is nose and 180o is tail

26. ADF FUNCTIONS AIRWAYS AIR ROUTES ILS LOCATORS – MARKER BEACONS
MARINE BEACONS
NDB APPROACHES
COMMERCIAL BROADCAST

27. ADF

28. ADF LIMITATIONS TWILIGHT EFFECT TERRAIN or MOUNTAIN EFFECT
JUST BEFORE/AFTER SUNSET/SUNRISE - fly high
GREATER AT GREAT DISTANCE – use less than 350 khz
TERRAIN or MOUNTAIN EFFECT
SHORELINE – signals crossing at less than 30o
ELECTRICAL STORMS
BANK ERROR – ALL TURNS
LOOP ANTENNAE ROTATES TO SENSE DIRECTION OF INCOMING SIGNAL AND IS MOUNTED PARALLEL TO NORMAL AXIS

29. ADF ADVANTAGES LOW COST INSTALLATION AND MAINTENANCE
NOT LINE OF LINE OF SIGHT SO GIVES GREATER RECEPTION AT LOWER ALTITUDES THAN VOR
PRIMARY NAVIGATION OVER LONG DISTANCE IN REMOTE AREAS

30. TRACKING TO THE STATION
PARALLEL TRACK
DESIRED TO HEAD
DETERMINES THE TURN
LEFT TURN
DESIRED TRACK – INTERCEPT ANGLE = INTERCEPT HEADING
RIGHT TURN
DESIRED TRACK + INTERCEPT ANGLE = INTERCEPT HEADING

31. TRACKING FROM THE STATION
PARALLEL TRACK
TAIL TO DESIRED
DETERMINES THE TURN
LEFT TURN
DESIRED TRACK – INTERCEPT ANGLE = INTERCEPT HEADING
RIGHT TURN
DESIRED TRACK + INTERCEPT ANGLE = INTERCEPT HEADING

32. SOME RULES
WHEN INTERCEPTING A TRACK TO OR FROM A STATION, BEARING INDICATOR ALWAYS AWAY
FROM 0 OR TOWARDS 180
2. WHEN TURNING, IF HEADING INDICATOR INCREASES, THEN ADF BEARINGINDICATOR (VALUE) DECREASES
HI LESS, ADF MORE
WHEN TRACKING, NEEDLE RIGHT? YES, THEN WIND IS FROM THE RIGHT SO TURN RIGHT, ETC.
MAGNETIC HEADING + RELATIVE BEARING = MAGNETIC BEARING TO THE STATION
MH + RB = MB TO THE STATION
MH = MB – RB
RB = MB - MH