Locator of plane going east or west (5)
I believe the answer is:
radar
'locator of plane' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for radar that I've seen before include "Technique using beam" , "System for locating distant objects" , "waves to expose foe" , "Navigational aid" , "Electronic tracker" .)