Navigation definitions Flashcards
Meridian
These are semi great circles that run north to south and join at the earths. True poles.
Prime Meridian.
0° of longitude, passes through Greenwich, England, near London.
International date line
Is located at 180° of longitude opposite side to the prime meridian.
(it makes some political jogs, so Russia and US don’t have a date change in their territory)
Add this meridian the day officially changes from one day to the next.
Meridian of longitude
Longitude is measured in degrees, minutes, and seconds.
Rhumb line
is an arc crossing all meridians of longitude at the same angle, that is, a path with constant bearing as measured relative to true north.
Magnetic variation
The angle difference between the magnetic meridians, and the true meridians
Whenever we convert true, heading to magnetic headings?
Variation east, magnetic least
Variation west, magnetic best
Agonic line
an imaginary line around the earth passing through both the north pole and the north magnetic pole, at any point on which a compass needle points to true north
Deviation
The angle through which the compass needle is deflected from the magnetic meridian, is called deviation
Deviation formula
Deviation East compass, least, deviation west compass best
Track
The direction an aircraft intends to travel over the ground
Heading
The direction the nose is pointed in relation to true or magnetic north
Bearing
This is an objects direction measured clockwise from a meridian
Drift
Wind blowing from the left or right, will cause the aircraft to drift away from its intended track
Air position
This is the theoretical position of an aircraft at a given moment, assuming it to have been unaffected in-flight by wind. Also known as no wind position.
Scale
Maps are made to scale. In each case the scale represents the ratio of a distance on the map to the actual distance on the ground.
What is the difference between latitude and longitude?
Longitude is measured from the prime meridian, based on an axis, passing through the true poles, while latitude is measured from the equator, based on a point at the earths center.
Unlike longitude lines. Lines of latitude, never converge that is why they’re called parallels.
Why do magnetic variations exist?
The geographical difference between true North, and magnetic north
VNC
Navigation chart
VFR flights in the low to medium altitudes
Straight lines drawn on this map are great circles (must know)
VNC validity
Validity dates are based on significant changes. When there are enough changes, a new VNC is produced on average every two years.
VTA
VFR terminal area chart
A straight line drawn on these charts is a Rhumb Line
Scale is 1: 250,000 or 1 inch to 4SM
Updated every two years
LO Chart
IFR flights at low altitude for used below 18,000 feet ASL
Updated every 56 days 
HI Chart
IFR flights at high altitude, for use at 18,000 feet ASL and above
Valid for 56 days
CFS
A joint civil and military publication, which contains all registered and certified Canadian Aerodromes
Also North Atlantic aerodromes
Revised and re-issued every 56 days
