1. 777 Neptune Groundschool
Navigation

2. The Graticule
The Graticule is a system of (imaginary) intersecting lines along the surface of the earth
Its purpose is for fast and accurate location
Consists of
Meridians of Longitude that run north – south, measuring East and West
Parallels of Latitude that run East – West, measuring North and South

4. Navigation terms
Pilotage is navigation with reference only to landmarks
Dead Reckoning is navigation via a predetermined route factoring wind, true airspeed, heading, groundspeed, and an estimated time of arrival
Radio Navigation is navigation by use of radio waves
Inertial Navigation is navigation via a built in compass
Satellite Navigation is navigation via use of GPS
The act of navigation consists of these various methods in combination with each other

5. Heading and Bearing
Heading is the direction of the longitudinal axis measured in degrees clockwise from north
North is 0 or 360
East is 90
South is 180
West is 270
Bearing is the measured of an angle between an observer and the object measures clockwise from north with reference to the observer

7. Variation The earth has two North Poles
True north – an arbitrary point on earth
Magnetic north – the north that all compasses point to
In special cases, where an observer stands, true north = magnetic north, in which case the observer is on an Agonic Line – line joining area of no variation
In most cases, the where the observer stands, true north ≠ magnetic north, in which case the observer is on an Isogonic Line – line joining areas of equal variation
The difference (in degrees) between true and magnetic north is Variation

9. Deviation
In an ideal world, a magnetic compass would point exactly to magnetic north
This is not the case due to interferences by external sources (other magnets, electronic waves, ect)
To account for this, we use Deviation – the difference between magnetic north, and the direction that the compass is pointing in

10. Determining heading
We now know that not all heading are the same, we have
True heading – based off true north
Magnetic heading – based off magnetic north
Compass heading – bases off the direction the compass points
When flying you have no way to actively determine true or magnetic north, only you compass heading
Compass heading is different, therefore there must be a way to convert between headings

11. Calculation of true, magnetic and compass heading
True heading
Variation
Magnetic heading
Deviation
Compass heading
+/- variation
True Track
Magnetic Track
+/- drift
+/- drift
+/- deviation
+/- variation
True Heading
Compass Heading
Magnetic Heading

12. Calculation of true, magnetic and compass heading
West (+)
East (-)
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
320°
6° West
???
Example:
True heading: 320°
Variation: 6° West
Magnetic Heading
???

13. Calculation of true, magnetic and compass heading
West (+)
East (-)
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
320°
6° West
326°
Example:
True heading: 320°
Variation: 6° West
Magnetic Heading
320° + 6° =
326°

14. ??? The other way around… West (-) East (+) ??? 3° West 256° Example:
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
???
3° West
256°
Example:
Compass heading: 256°
Deviation: 3° West
Magnetic haeading.
???

15. 256° - 3° = 253° The other way around… West (-) East (+) 253° 3° West
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
253°
3° West
256°
Example:
Compass heading: 256°
Deviation: 3° West
Magnetic haeading.
256° - 3° =
253°

16. ??? ??? West (-) East (+) 5° West 005° Example: Compass heading: 005°
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
???
5° West
005°
Example:
Compass heading: 005°
Deviation: 5° West
Magnetic haeading.
???

17. 005° - 5° = 360° West (-) East (+) 360° 5° West 005° Example:
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
360°
5° West
005°
Example:
Compass heading: 005°
Deviation: 5° West
Magnetic haeading.
005° - 5° =
360°

18. Calculation of true, magnetic and compass heading
West (+)
East (-)
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
010°
020°
3° East
Example:
True heading: 010°
Variation: ???
Magnetic Heading
010° + ???° =
020°

19. Calculation of true, magnetic and compass heading
West (+)
East (-)
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
010°
020°
3° East
Example:
Magnetic Heading: 020°
True heading: 010°
Variation
020° ° =
010° West

20. Calculation of true, magnetic and compass heading
West (+)
East (-)
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
010°
010° West
020°
3° East
???
Example:
Magnetic Heading: 020°
Deviation: 3° East
Compass Heading
???

21. Calculation of true, magnetic and compass heading
West (+)
East (-)
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
010°
010° West
020°
3° East
017°
Example:
Magnetic Heading: 020°
Deviation: 3° East
Compass Heading
020° ° =
017°

22. ??? 12° East ??? West (-) East (+) 4° West 005° Example:
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
12° East
???
4° West
005°
Example:
Compass heading: 245°
Deviation: 4° West
Magnetic haeading.
???

23. 005° - 004° = 001° 12° East 001° West (-) East (+) 4° West 005°
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
12° East
001°
4° West
005°
Example:
Compass heading: 245°
Deviation: 4° West
Magnetic haeading.
005° ° =
001°

24. ??? 12° East 001° West (-) East (+) ??? 4° West 005° Example:
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
???
12° East
001°
4° West
005°
Example:
Magnetic Heading: 241°
Variation: 12° East
True Heading
???

25. 001° + 012° = 013° 12° East 001° West (-) East (+) 013° 4° West 005°
True Heading
Variation
Magnetic Heading
Deviation
Compass heading
013°
12° East
001°
4° West
005°
Example:
Magnetic Heading: 241°
Variation: 12° East
True Heading
001° + 012° =
013°

26. Question

27. Question