Navigation Quiz 2

Question 1) Parallels of latitude:

Are described as being either east or west of 0°

Are all small circles, except for the equator

Are all great circles

Are numbered from 0° to 180°

Correct! Wrong!

Parallels of latitude are ‘small circles’ arranged vertically on the Earth with the equator used as a datum. Small circles do not intersect the centre of the earth like ‘Great Circles’. The only parallel of latitude which is not a small circle is the equator. As this intersects the centre of the Earth it is a great circle.

Question 2) If the scale of a chart is given as 1:500,000 which of the following statements is true?

500,000cm on the chart represents 1 nm on the earth’s surface

1cm on the chart represents 500,000km on the earth’s surface

1cm on the chart represents 500,000cm on the earth’s surface

The scale is greater than a chart with a 1:250,000 scale

Correct! Wrong!

A chart scale is a ratio between Earth distance and chart distance. It is important that the units are the same. So 1cm on the chart equates to 500,000cm on the Earth. (This is the same as 5km or approx 2.7NM).

Question 3) A class B VDF bearing is accurate to:

+/- 5°

+/- 2°

+/- 10°

+/- 8°

Correct! Wrong!

Classes of accuracy in VDF bearing are: Class A +- 2°, Class B +- 5°, Class C +-10°

Question 4) When using a DME what range is displayed on the cockpit display?

Slant Range

Horizontal Range

Corrected Slant Range

Arc Range

Correct! Wrong!

DME uses the principle of slant range rather than horizontal range. As a result if the aircraft is directly overhead the beacon, the distance shown will be the aircraft’s height. 6000ft is roughtly 1NM. Therefore an aircraft flying at 6000ft directily above a DME station will see a distance read out of 1NM on the display.