Definition
On a Horizontal Situation Indicator (HSI), the course-indicating arrowhead is the pointer at the head of the course-select needle that shows which direction along the selected course points outbound from the aircraft. It rotates with the compass card as the course is set, and the heading the arrowhead aligns with on the compass card is the selected course in degrees.
Plain English
It is the arrow tip on the HSI that shows you which way the course you have dialed in is pointing. Whichever number on the compass card the arrow is touching is the course you have selected.
Context Anchor
Seen on the HSI when selecting, confirming, or following an instrument course.
Derivation
Course comes from a Latin word meaning a running or path. Indicating means pointing out. Arrowhead is the pointed end of an arrow. Together, the term means the pointed part of the instrument arrow that points out the selected path.
Why Pilots Care
Allows the pilot to quickly confirm the selected course heading without misinterpreting the instrument display.
Analogy
It is like the pointed end of an arrow drawn on a map: the line shows the path, and the point shows the direction along that path.
Intuition Check
Do not think of the arrowhead as a moving airplane symbol. It does not show where the aircraft is pointing; it shows the direction of the course selected on the instrument.
Example Sentence 1
After tuning the VOR, she rotated the course knob until the course-indicating arrowhead sat on 270 degrees on the compass card.
Example Sentence 2
With the course-indicating arrowhead pointing north, the aircraft was established on the inbound course to the VOR.