GNav

Question 1

What are isoclines ?

Answer 1

Lines of constant dip

Question 2

What are aclinic lines ?

Answer 2

Magnetic equator where lines are horizontal so there is no dip

Question 3

What are agonic lines?

Answer 3

Lines of zero variation

Question 4

What is departure formula ?

Answer 4

Departure = CHLong(mins) X cos(CHLat)

Departure (distance) normally in NM

Question 5

What is earth convergence formula ?

Answer 5

Convergence = CHLong (degrees) X sin(CHLat (mean))

Question 6

What is the conversion angle formula ?

Answer 6

0.5 X earth convergence

Then minus or add that to track direction

Question 7

What is CHLat distance formula ?

Answer 7

Distance = CHLat X 60

Question 8

What cause magnetic north to move ?

Answer 8

Solar wind
Sun variation
Poles move in loops, up to 45 No per day

Question 9

Which month does Aphelion occur ?

Answer 9

July - Earth is furthest away from the sun

Question 10

What is the highest latitude which the sun can be vertically overhead ?

Answer 10

23.5 degrees

Question 11

Which months see biggest difference between apparent and mean noon ?

Answer 11

February and November

Question 12

What time of year does earths length of daylight change the most ?

Answer 12

Autumn and spring

Question 13

What is the mean sun ?

Answer 13

When a fake sun collides with the real sun at the spring equinox and travels along the celestial equator

Question 14

What is celestial ?

Answer 14

Fictitious position relating to earths globe.

So there’s a imaginary equator, poles, sun etc

Question 15

Which way does Earth orbit around the sun and on its plane ?

Answer 15

Anti-clockwise

Question 16

What is the circumference of the earth ?

Answer 16

40,000km

Question 17

What is the diameter of the earth ?

Answer 17

12730 Km

40000/Pi

Question 18

What is the radius of the earth ?

Answer 18

6730 Km

Question 19

What is the latitude which the maximum difference between geocentric and geodetic occurs ?

Answer 19

45 N/S

Question 20

What are rhumb lines ?

Answer 20

They are small circles. They concave to the poles. They cut meridians at same angle. They are also half meridians, as a meridian only does a 180 of the earth and not 360 around it, which is what a great circle is, 360.

Question 21

When does pherihelion occur ?

Answer 21

4th January.

Question 22

What are Keplers laws ?

Answer 22

First law pherihelion and apherihelion

Second law; further away from the sun the earth is, the slower it orbits, and the closer the earth is to the sun the quicker earth orbits

Question 23

When is the spring equinox ?

Answer 23

20/21 March

Question 24

When is the autumn equinox ?

Answer 24

22/23 September

Question 25

When is the summer solstice ?

Answer 25

21/22nd June

Question 26

When is the winter solstice ?

Answer 26

21/22nd December

Question 27

What is the major formula ?

Answer 27

(Minor/297)X298

Question 28

What is the minor formula ?

Answer 28

Major - major/298

Question 29

What are great circles ?

Answer 29

They convex to poles, cut meridians at different angles

Question 30

What is formula for True air temperature?

Answer 30

Static air temperature + Ram Rise

Question 31

What is the formula for Static air temperature ?

Answer 31

True air temperature - ram rise

Question 32

Companies which contract datalink:

Answer 32

SITA

ARINC

Question 33

Who are the satellites operated by ?

Answer 33

INMARSAT