Final answer:
True heading and true track are used to determine an aircraft's direction of flight. Runway heading is the direction of the runway, while true track is the direction the aircraft is moving over the ground. True track is used to determine cruising altitude in lieu of magnetic track.
Step-by-step explanation:
In aviation, the terms true heading and true track are used to determine the aircraft's direction of flight. True heading refers to the direction an aircraft is pointing relative to true north, while true track refers to the direction an aircraft is moving over the ground relative to true north. Runway heading, on the other hand, refers to the direction of the runway itself, which may not necessarily align with true north.
When determining cruising altitude for a specific direction of flight, true track is used instead of magnetic track. Magnetic track is the direction an aircraft would need to fly in order to follow a specific magnetic course, but it can be influenced by magnetic variations and compass errors. True track, on the other hand, is the direction an aircraft is actually moving over the ground relative to true north and provides a more accurate indication of the aircraft's path.