Navigation basics — transcript

00:00:00.400 --> 00:00:05.259 Navigation basics: where you are, which way you're heading, and how to call it.

00:00:06.700 --> 00:00:11.901 Parallels of latitude run parallel to the equator, numbered north and south of it.

00:00:11.901 --> 00:00:16.914 Meridians of longitude run pole to pole, numbered east and west from Greenwich.

00:00:18.400 --> 00:00:22.410 Together they give any point an address, latitude first.

00:00:22.410 --> 00:00:28.038 Brisbane is about twenty-seven twenty-eight south, one fifty-three oh two east.

00:00:28.038 --> 00:00:30.782 Each degree splits into sixty minutes.

00:00:31.132 --> 00:00:35.547 Direction is measured clockwise from north, always as three figures.

00:00:35.547 --> 00:00:38.681 Zero three zero. One four zero. Three zero zero.

00:00:40.132 --> 00:00:43.349 Maps measure from true north, along the meridians.

00:00:43.349 --> 00:00:46.250 A compass follows the earth's magnetic field.

00:00:46.250 --> 00:00:51.548 The angle between them is magnetic variation, shown on charts as a dashed isogonal.

00:00:52.632 --> 00:00:56.852 Say a track is zero four five true, with ten east variation.

00:00:56.852 --> 00:01:02.663 From magnetic north it's ten less: zero three five. Variation east, magnetic least.

00:01:03.632 --> 00:01:09.882 Same track, ten degrees west: magnetic is ten more, zero five five. Variation west,

00:01:09.882 --> 00:01:10.999 magnetic best.

00:01:11.832 --> 00:01:15.899 Why it matters: near an aerodrome, you give your bearing in magnetic.

00:01:15.899 --> 00:01:19.617 Two five five true on the chart becomes two four five magnetic.

00:01:22.232 --> 00:01:26.544 Runway numbers are magnetic too, to the nearest ten degrees.

00:01:26.544 --> 00:01:32.341 Runway zero four points zero four zero magnetic. The other end is runway two two.

00:01:32.832 --> 00:01:36.404 For traffic, use the clock code. Twelve is straight ahead.

00:01:36.404 --> 00:01:40.460 Two o'clock is about sixty degrees right; ten o'clock, sixty left.

00:01:40.460 --> 00:01:41.792 High means above you.

00:01:43.532 --> 00:01:47.659 Aircraft, two o'clock high! Your observer calls it, and you look right and up.

00:01:50.132 --> 00:01:55.502 Final check. The chart gives one eight zero true. Variation is eleven east.

00:01:55.502 --> 00:01:57.551 What's the magnetic bearing?

00:01:57.901 --> 00:02:00.304 One six nine magnetic. East is least.