The Compass

Traveling a steady course

The animal kingdom is blessed with great navigators, migrating thousands of miles without so much as a Rand-McNally, but for us non-feathered, less furry bipeds we can't travel a steady course without some form of reference. Try it next time without your compass or a visual reference, you will invariably find your course degrades into no better then a cattle path through a pasture.
You'll swear you were traveling a straight line, but your path bore a striking resemblance to a pretzel.

The Compass

Luckily for us the Earth has a magnetic field which is roughly aligned with the north and south poles. Since like magnetic poles repel and opposites attract, a magnet allowed to rotate freely will align itself with these magnetic poles. Because true north and magnetic north aren't exactly the same you will find that maps and sectionals as well as the VORs on them show the magnetic declination for that point on the globe. Along the west coast of the US these lean towards the east and the east coast VORs tilt westward.

Based on these poles we have determined the directions North, East, South and West and assigned numerical values ranging from 000 to 360.

North- 360 or 000

East- 090

South- 180

West- 270



As a result it allows us to set our course with a relatively high degree of accuracy.



For example if we want to fly precisely

-North East we'll set a course of 045
-South East would be a course of 135
-South West would be a course of 225
-North West would be a course of 315



Compass as seen in most of the helos


The compass and others instruments like it have given us the ability to consistently steer our aircraft on a desired magnetic heading with a reasonably high degree of accuracy which is an integral part of navigation.

You'll recall the need to be able to determine your location, determine your destination, and determine a way to get from your location to your destination accurately. If you know your position and what heading you need to fly to get there but are unable to steer or maintain that heading your not likely to get there consistently or with any degree of accuracy. As a result the compass even as simple as it is, is still an integral tool for navigation.