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
19
Q
Isogonic Lines (Isogonals)
A
Lines on a map joining places of equal variation
20
Q
Agonic Lines
A
Line on a map joining places of zero variation
21
Q
Effect of Variation
A
- Compass always points toward magnetic north
- If magnetic pole differs east or west from true pole, there will be easterly or westerly variation
22
Q
Conversion of True and Magnetic
A
- Variation west magnetic best (Add)
- Variation East Magnetic Least (Subtract)
23
Q
Magnetic Compass
A
- Principal instrument for determining direction
- Reliable during level constant airspeed flight and Constant rate climbs or descents
- Self-contained
- Requires no external power
24
Q
Magnetic Compass Construction
A
- 2 North seeking magnets
- Attached to a float which has the compass card on it
- Mounted on a pivot and can rotate
- All inside the compass bowl
- Filled with a liquid to dampen oscillations
- Container has an expansion chamber for temperature changes
- Housing made of brass - non-magnetic
- Graduated in 5º intervals
25
Compass Errors - Deviation
- The angle the compass needle is deflected due to any magnetic interference to the compass
- Caused by airframe, radios, electrical systems, anything else metal or producing a magnetic field
- Must correct for deviation when using compass
- Compass Swinging correct for deviation
- Compass is aligned with known points painted on the ground far from metal hangers etc.
- Adjustment screws on the compass used to correct the displayed compass heading
- A compass correction card is placed in the cockpit
26
Northerly Turning Error
- Caused since compass bowl is no longer parallel with the earth's surface
- Turns to or from North cause the compass to lag or show a turn in the opposite direction
- Turns to or from south cause the compass to lead
- Maximum on headings of north or south
- Minimum on headings of north or south
- Minimum on headings of east or west
- South Advance North Delay
27
Acceleration Error
- When accelerating or decelerating, the centre of gravity of the compass tends to lag behind
- On east and west headings this causes a turning moment in the compass
- No effect on north and south headings
- Acceleration shows to turn to north
- Deceleration causes turn to south
- ANDS
28
GPS Navigation
- Available all over the planet in any weather condition in theory
- 24 satellites in 6 distinct semi-synchronous orbits, also called a constellation of satellites
- Each satellite completes one orbit in 12 hours
- Each satellite contains 4 atomic clocks, all are extremely accurate
29
GPS Navigation - The Space Segment
Satellites orbiting the earth
30
GPS Navigation - The Control Segment
- Consists of Master Control Station and monitor stations
- Master control station controls tracking, monitoring and updating satellites
- Each of the monitor stations checks the exact altitude, position, speed, and overall health of the orbiting satellites
31
GPS Navigation - The User Segment
- Consists of the GPS receiver and an antenna
- The antenna must be on the top of a metal aircraft
- Time required for signal to reach receiver is directly related to distance from satellite
- Satellites transmit signal with time stamp and position in orbit
- Receiver solves for arriving signal time and satellite positions to calculate position
- Uses change in position updated once per second to determine velocity
- Need a minimum of 4 satellite signal connections for accurate position
32
Aeronautical Charts
- Maps
- Representations of a sphere on a flat surface with distortions
- Certain things preserved depending on purpose
33
Elements of Map Construction
- Areas
- Shapes
- Bearings
- Distances
34
Lambert Conformal Conic Projection
- Based on superimposing a cone over the surface
- Meridians are straight lines converging toward the nearer pole
- Parallels are curved away from the near pole
- Scale is accurate over the entire map within 0.5%
- Straight line drawn between 2 points represents a great circle
- VFR navigation charts and IFR enroute charts
35
Mercator Projection
- Based on superimposing a vertical cylinder over the surface
- Meridians and parallels are straight and parallel lines
- Scale is not constant over entire map
- Area in higher latitude is exaggerated
- Straight line is rhumb line
36
Transverse Mercator Projection
- Eliminates distortions of mercator
- Meridians converge toward nearer pole
- Parallels curve away from nearer pole
- Curvature is low over small areas
- Accurate only on selected meridian
- VFR Terminal Area Charts
37
VFR Navigation Charts (VNC)
- Used for low level, low speed visual navigation
- Chart is printed on both sides to cover the desired area, Northern and Southern half
- Charts named based on principal landmark
- Publication date located on chart
- Based on Lambert Projection
38
VFR Terminal Area Charts (VTA)
- Used for visual navigation around busy terminal areas
- Published for those airports with classified airspace for control purposes
- Depicts visual checkpoints and call-up points
- Frequency and airspace classifications shown
- Publication date is located on the chart
- Based on Transverse Mercator Projection
39
Enroute Charts
- Provide information for radio-navigation over designated areas
- Low Altitude Charts (Up to FL180)
- High Altitude Charts (Above FL180)
- No visual landmarks, only radio aids
- Each chart has its own scale
40
VNC Charts - Legend
- Title and Visibility
- Aerodromes
- Aerodrome Data
- Airspace Information
- Radio Aids to Navigation
- Data Boxes
- Air/Ground Communication Boxes
- Miscellaneous
41
Route Selection
- A straight line is the shortest distance
- Select a route that has landmarks to navigate with
- Ensure the airspace is safe to fly through
- Ensure terrain is sage to fly over, consider a forced approach
- Must maintain gliding distance from shore
- Note if a fuel stop is required
- Make sure you have the correct radio or nav equipment
42
Lost Procedures
- Look for landmarks
- Climb higher for a better view
- Read name of town off water tower
- Request Radar assistance
- VOR, ADF, or GPS
- Circle of uncertainty
- Right hand triangular pattern in Radar Airspace
43
Preventing Getting Lost
- Stay ahead of the plane
- Do thorough flight planning
- follow planning and make corrections
- Avoid using the visual altercation method
- be familiar with route
- avoid bad weather
- always have a map and CFS
44
Remote Communications Outlet (RCO)
- Antenna sends communication along an open phone line to an FSS
- Provides Flight Information Service Enroute (FISE)
- Provides Remote Aerodrome Advisory Service (RAAS)
45
Dial-up Remote Communications Outlet
- Antenna sends communication to an FSS only when activated by the pilot
- Key Mic 4 times to activate, you will hear dialing and then "Link Established"
- Talk per normal communications
