ATPL Nav Fundimentals

Question 1

What is Grivation?

Answer 1

A combination of Variation and Convergence.

Is the difference between Grid North and Magnetic North.

Question 2

What type of charts are more commonly used for Navigation in the Mid Latitudes?

Answer 2

Lambert conformal as they are more accurate then Mercator charts

Question 3

1nm = …..m?

Answer 3

1852m

Question 4

1nm = …… SM?

Answer 4

1.152 Statute Miles

Question 5

1nm = ….. Ft?

Answer 5

6080ft

Question 6

1sm = ……m?

Answer 6

1610m

Question 7

1m = ….ft?

Answer 7

3.28ft

Question 8

1ft = …..m?

Answer 8

0.3048m

Question 9

1ft = ….in?

Answer 9

12 inches

Question 10

1in = …..cm?

Answer 10

2.54cm

Question 11

ISA Temperature Lapse Rate?

Answer 11

1.98 Degrees up to 36,090ft where it is isothermal at -56.5 degrees

Question 12

JSA Temperature Lapse Rate

Answer 12

2 Degrees/1000ft with no correction at the tropopause

Question 13

Factors affecting twilight

Answer 13

• Latitude (the biggest factor)
• Season
• The height of the Observer

Question 13

Define Visability

Answer 13

The greatest distance at which a black object of reasonable dimension, situated near the ground can be seen and recognised when observed against a bright background.

Question 14

Factors affecting Visibility range

Answer 14

• Background Colour
• Whiteout
• The Sun
• The moon

Question 15

What is RVR and when is it reported?

Answer 15

Runway visual range - is the horizontal visibility along the runway as seen from a point 5m above the touchdown point.

It is reported when visibility reduces below 1500m.

Mid point and stop end will be reported when it is below the touchdown point value or when Visibility is below 600m

Question 16

What are the ideal properties of a Navigation chart?

Answer 16

• Bearings in a chart should represent bearings on the Earth.
• All shapes should be correctly represented.
• Great circles and Rhumb lines should both be straight lines (Not Possible)
• Scale correct and constant at all points on earth.
• Longitude and Latitude to cross at 90 Degree angles.

Question 17

What makes a chart Orthomorphic?

Answer 17

• All latitudes and Longitudes meet at 90 Degree angles.

* Has Correct scale.

Question 18

Properties of a Mercator Chart?

Answer 18

• Orthomorphic
• Cylindrical projection.
• Scale not constant (is only exact at the equator (increases as latitude increases))
• Cannot be used above 70N/70S
• Rhumb lines are straight
• Great circles are convex to the nearest pole.
• Distance difficult to measure
• Not used in aviation.

Commonly used in equatorial regions.

MRS CONVEX POLE:

M - Mercators
R - Rhumb lines are
S - Straight
CONVEX POLE - Great circles.

Question 19

Lambert Conformal Conic Projections Chart properties?

Answer 19

• Orthomorphic
• Conic Projection (Cone)
• Constant scale
• Poles are projected
• Great Circles are straight
• Rhumb lines are curved ( Concave to the nearest pole.
• Distance easily measured
• Widely used in aviation