compass course

Definition

The course measured in degrees from magnetic north, then corrected for the deviation error of the specific aircraft's magnetic compass. It is the heading you actually fly using the compass to track a desired course over the ground, after accounting for wind correction, magnetic variation, and compass deviation.

Plain English

The number of degrees you read on the compass when you are flying the path you want, after adjusting for everything that pulls the compass needle off true direction.

Context Anchor

Seen in magnetic compass error discussions, navigation planning, and any situation where a pilot converts a planned magnetic direction into what the cockpit compass should show.

Derivation

Compass' comes from the Latin 'com-' (together) and 'passus' (step or pace), originally meaning to measure out or mark a circle. 'Course' comes from the Latin 'cursus' meaning a run or path. Together: the path measured by the compass.

Why Pilots Care

Prevents navigation errors by compensating for the aircraft's own magnetic interference that would otherwise cause heading mistakes.

Intuition Check

Course does not mean a class or lesson here. In this context, it means the direction of the intended path, expressed in degrees.

Example Sentence 1

After applying variation and deviation to the true course, the pilot determined a compass course of 087 degrees.

Example Sentence 2

Preflight planning adjusted the compass course from the magnetic course to account for known deviation at that heading.

Definition

The course flown as read directly on the magnetic compass. It is the true course corrected for magnetic variation, wind drift, and compass deviation, expressed as a heading the pilot can fly by reference to the aircraft's compass.

Plain English

The number you actually fly on the compass to get where you're going, after adjusting for the difference between true north and magnetic north, the wind pushing you sideways, and small errors in the compass itself.

Context Anchor

Seen in cross-country flight planning, navigation logs, and discussions of how to convert a chart course into a compass indication the pilot can use.

Derivation

Course' comes from the Latin cursus, meaning 'a running' or 'path.' A compass course is therefore the path as told to you by the compass — not the path drawn on the chart, and not the path corrected only for magnetic variation.

Why Pilots Care

Using the correct compass course keeps the aircraft on the planned track despite local magnetic influences from the airframe.

Intuition Check