Which item is not a wind direction indicator?

• A. Wind sock.
• B. Wind tee.
• C. Tetrahedron.
• D. Altimeter.

Answer: (D)

Wind direction indicators are devices that show where the wind is coming from or which direction it is blowing toward. A wind sock, wind tee, and a tetrahedron all serve that purpose by aligning with the wind to reveal direction. The wind sock lengthens or shortens with wind strength and points roughly downwind, the wind tee has a vertical post with a horizontal arm that points into the wind, and the tetrahedron on a mast aligns with the wind to indicate direction. The altimeter, on the other hand, measures altitude above a reference level and does not provide any information about wind direction. So, the altimeter is not a wind direction indicator.