Nav #1 Flashcards
What are the four essential problems of Air Navigation?
Where are we? Where are we going? How will we get there? When will we get there?
Describe the two components of Air Navigation.
The art and science of safely and efficiently directing an aircraft from one place to another, and determining the aircrafts position at any time.
What is the shape of the Earth for practical navigational purposes?
A perfect sphere.
What is the shape of the Earth?
An oblate spheriod.
Define the True Poles.
The extremities of the diameter about which the Earth rotates.
Define the Magnetic Poles.
The extremities of the diameter indicated by a North seeking magnet.
Define a Great Circle.
A line on the surface of the Earth with a centre and radius the same as the Earth.
Define the Equator.
A great circle which is perpendicular to the axis of rotation and equidistant from both poles.
Define Parallels of Latitude.
Small circles that parallel the Equator.
Define Meridians.
Semi-great circles that join the poles.
Define Rhumb Lines.
A regularly curved line that cuts all meridians at a constant angle.
List the four major properties of an Aviation Map or Chart.
Latitude/Longitude grid. Elevation in feet. Mercator or Lamberts projection. Centrally controlled.
List the properties from an ideal map.
Conformity. Constant scale. Equal Area. Great Circles or Rhumb Lines are straight. Adjacent maps fit together. Geographic position is easily located.
What is the problem when representing a curved surface onto a flat map or chart?
Distortion.
List the three properties of Conformity?
Scale expansion/contraction from any point is independent of azimuth/direction. Shape on the chart conforms with the area being portrayed. Meridians and parallels cut at right angles.
List the properties of a Mercator Projection.
Great Circle is a curved convex to the pole. Scale is constant only at the standard parallel. Bearing are correct. Rhumb Lines are straight. The equator and meridians are the only great circles.
List the limitations of a Mercator Projection.
Can’t depict the poles. Must apply conversion angles to great circle tracks. Distortion of large shapes. Large distances difficult to measure. Limited to 70ºN - 70ºS. Rhumb Lines are straight lines. Great Circle is a curved convex to the pole.
List the properties of a Lamberts Conformal projection.
Great circles are straight lines. Rhumb Lines are curved concave to the nearest pole. Has two standard parallels. Scale considered constant. Conformal (I.e. bearings and shapes are correct). Maps fit East-West is the same standard parallels used on each map.
Care must be taken when plotting on a Lamberts Chart due to what?
Lines of Latitude convergence. Lines of Longitude convergence. Great Circle convergence. Rhumb Line convergence.
List the two methods of expressing the scale of a chart.
Fraction (1:100 000) and Statement (one inch to one mile)
List the three ways geographic position can be expressed in air navigation.
Place name. Bearing and distance. Latitude and Longitude.
List the six elements of the vectors of the Triangle of Velocities.
Heading. Track. TAS. Ground Speed. Wind direction. Wind speed.
State the need for safety height calculation.
We need to be able to determine safety of heights because of operations off designated airways.
Safety heights must be determined when?
Within 25nm of an airfield with a Minimum Safety Altitude (MSA). Outside 25nm of an airfield with a MSA. Departing from a non-licenced airfield with a MSA. On a track with a published LSALT.
