Navigation 1 Flashcards
1
Q
Methods of Navigation - Pilotage
A
An organized system with reference to the Earth’s surface
2
Q
Methods of Navigation - Dead Reckoning
A
“Point and Shoot” using the Earth’s surface
3
Q
Methods of Navigation - Radio Navigation
A
Means Without reference to Earth’s surface
4
Q
Methods of Navigation - Celestial Navigation
A
Using reference to the stars
5
Q
Methods of Navigation - GPS Navigation
A
Receiving Global Positioning System signals for the purpose of determining your current location on Earth
6
Q
Degrees to Minutes
A
1º = 60’
7
Q
Minutes to Seconds
A
1’ = 60”
8
Q
Latitude
A
- Parallels of Latitude
- Run parallel to equator
- Measured from 0º-90º north or south of the equator
- Distance between each degree of latitude is 60 NM
- Each minute of latitude is then 1 NM
9
Q
Longitude
A
- Meridians of Longitude
- Lines on a map joining the geographic (true) poles of the earth
- Run North to South
- Measure from 0º-180º east and west of the Prime Meridian
- 180º Line is International Date Line
- Distance between longitudes at equator is 60 NM
- Decreases the further north or south you go
10
Q
Geographical Coordinates
A
- Positions of landmarks obtained using Latitude and Longitude
- Expressed in latitude first then longitude
11
Q
Time and Longitude
A
- Earth rotates 360º/24 hours
- 15º/hour
- Hence the Need for standard time and 24 different time zones
12
Q
Standard Time
A
- Based on 0º Longitude (Prime Meridian)
- Runs through Greenwich England
- Time in Greenwich = Greenwich Mean Time (GMT, UTC or Zulu Time)
- All ATC and MET Times reported in UTC
13
Q
Great Circles
A
- Line over the surface of the earth that would cut it in half if extended over the entire surface
- Equator is only parallel of Latitude that is a Great Circle
- Meridians are semi-Great Circles because they don’t encircle the entire Earth
- Great Circle Route is the shortest distance between two points on Earth
- Does not cut Meridians at same angle
- Aircraft must constantly adjust heading as it flies
14
Q
Rhumb Lines
A
- Curved Line on the earth that meets each meridian at the same angle
- Allows pilots to fly a constant heading (Advantage)
- Unless the track is on a meridian, the route would be longer than a Great Circle (Disadvantage)
15
Q
Bearing
A
- Direction of an object from an observer or our position relative to a point
- Measured in degrees from North
16
Q
Earth’s Magnetism
A
- North and South Magnetic Pole
- Lines of force exist between these 2 poles
- Creates Magnetic Field around Earth
- Compass needle will align itself with these lines of force
- North seeking end will point north
- Magnetic field lines are horizontal over the equator and vertical at the poles
- Horizontal part makes compass magnet point north
- Vertical part makes north seeking end point down (This occurs in northern latitudes)
17
Q
Magnetic Dip
A
- The effect of the vertical forces is to cause the compass to “Dip” or point down
- The compass can compensate up to a certain point since it is mounted on a pivot
- Beyond this the compass becomes unusable
- Geographic area called “Area of Compass Unreliability”
- Marked on maps and charts as the Northern Domestic Airspace (NDA)
- Balancing the magnet system pendulously on a pivot point, centre of gravity of compass is below pivot point
- centre of buoyancy is above centre of gravity
18
Q
Variation
A
- Earth has both magnetic and geographic North and South Poles, don’t lie on the same place on the surface
- Magnetic poles move slowly from year to year
- Magnetic Meridians do not coincide with the True Meridians
- Navigation is more challenging since we have a magnetic compass and maps reference True North
