Which statement defines a compass course?

• A. A low-power, low- or medium-frequency radio beacon at the ILS outer or middle marker.
• B. A small circle showing direction in degrees.
• C. The time ATC uses to void clearance after takeoff.
• D. A true course corrected for variation and deviation errors.

Answer: (D)

Compass course is the true course adjusted for magnetic variation and local compass deviation, giving the direction you would actually fly as indicated by the instrument. Start with the true course (direction relative to true north), then apply variation (the difference between true north and magnetic north) and finally account for deviation (errors within the aircraft’s compass caused by magnetic interference). The result is the compass course—the course you use to fly that aligns with what your magnetic compass will indicate. The other options describe marker beacons, a generic circular direction indicator, or a timing value used by ATC, none of which define compass course.