Definition
A condition on a VOR or localizer course indicator in which the needle moves opposite to the direction the pilot must steer to return to the selected course. It occurs on a VOR when the OBS is set to a course 180° from the one being flown (a TO/FROM mismatch), and on a localizer when the aircraft is flying the back course without a back-course function selected on the instrument.
Plain English
The needle is telling you the truth, but backwards. If you fly toward the needle as you normally would, you steer further away from the course instead of correcting onto it.
Context Anchor
Seen during instrument navigation, especially when using a course needle on a VOR or localizer approach.
Derivation
From 'reverse' (turned the opposite way) and 'sensing' (how the instrument senses your position relative to the course). The term simply describes that the instrument's left/right sense is reversed from what the pilot expects.
Why Pilots Care
Recognizing reverse sensing prevents incorrect turns that can take the aircraft farther from the intended course and increase workload or risk.
Analogy
It is like looking at your movement in a mirror: the information is there, but left and right can feel swapped if you are not expecting it.
Intuition Check
Reverse sensing does not mean the navigation signal is necessarily bad. It means the indication is reversed from the correction you would normally make.
Example Sentence 1
When the student flew the localizer back course with the front-course frequency set normally, he experienced reverse sensing and had to mentally fly away from the needle to stay on course.
Example Sentence 2
During the VOR approach the pilot noticed reverse sensing after inadvertently selecting the outbound course instead of the inbound radial.