Compass and headings

Directions in aviation are given in three figures measured clockwise from north: 000° (north), 090° (east), 180° (south), 270° (west). Say "zero niner zero", not "ninety".

• True north — towards the geographic North Pole (the top of a map).
• Magnetic north — where a compass needle points. The angle between them is variation (small in Malaysia, about 0–1°).
• Deviation — compass error caused by the aircraft's own metal and electrics, listed on a deviation card.

Memory aid: "Variation west, magnetic best; variation east, magnetic least" — add westerly variation to a true heading to get the magnetic heading; subtract easterly.

Heading is where the nose points; track is the path over the ground. With a crosswind the two are different.