Earth dims, CDMVT, dip (22-05-18) Flashcards
What is the circumference of the earth?
21600nm
What is the radius of the earth at the equator?
6883.7nm
What is the inclination of the Earth in its orbit?
23.5deg
What is the radius of the Earth at the poles?
6860.6nm
What is the diameter at the equator called?
The major axis
What is the diameter of the earth at the poles called?
the minor axis
What is the earths compression factor?
1/298
0.3%
What is the world standard for charts?
WGS84
Regarding heading and track, which way to aircraft always drift?
From heading to track
What is a sidereal circuit?
The 960 year cycle that the magnetic pole rotates around the true North Pole.
What is an isogonal?
A line on a chart joining points of equal variation.
What is an agonic line?
A line on a chart joining points of zero variation.
Where does deviation originate from?
The localised magnetic fields produced by circuitry in the plane.
What is it called when 2 things are directly opposite each other, such as the true north and South Pole.
Antipodal
What is magnetic dip?
Where the earths magnetic field is slightly inclined to the horizontal due to being closer to the poles.
When is horizontal directive force the strongest?
Half way between the magnetic poles.
What is magnetic field strength measured in?
Micro Teslas
muT
What are isoclines?
Lines on a chart joining points of equal magnetic dip.
What is an aclinic line?
Lines on a chart joining points of zero dip
(magnetic equator)
What would call for compass swing to happen?
Reported fault
scheduled servicing
struck by lightning
major component change
static on ground for a long period
A/C changes working latitude
A/C has carried ferrous material
What is meant when a material is permeable?
It is easily magnetisable
What is meant by soft iron magnetism?
When a material is easily magnetisable but also loses magnetism quickly
What is meant by hard iron magnetism?
When a magnetised material retains its magnetism for a long duration.
