Course
Course is the intended direction of flight measured as an angle from a reference direction (true north or magnetic north). It is the direction the aircraft is intended to track over the ground — as opposed to heading, which is the direction the aircraft nose is pointed (which differs from course when there is a crosswind).
Course vs. Track vs. Heading
- Course: The planned direction of flight over the ground — what you intend to fly
- Track (TMG — Track Made Good): The actual direction the aircraft is moving over the ground — measured GPS ground track
- Heading: The direction the aircraft nose is pointed — differs from track due to wind correction angle (crab angle)
True vs. Magnetic Course
Courses are initially plotted as true courses on topographic or aeronautical charts, then converted to magnetic course by applying magnetic variation, then converted to compass heading by applying compass deviation. The mnemonic TVMDC (True Variation Magnetic Deviation Compass — or “True Virgins Make Dull Company”) helps remember the conversion sequence.
On the TC Written Exam
The course/heading distinction and the TVMDC conversion are regularly tested. Know: wind correction angle converts course to heading; variation converts true to magnetic; deviation converts magnetic to compass.