Practice VOR navigation with an interactive top-down map and realistic instrument display. Understand radials, OBS settings, CDI deflection, and TO/FROM indications.
Current Radial
R-090
OBS Set
090°
CDI Deflection
0.0 CTR
TO/FROM Flag
FROM
Click the +5/-5 buttons to rotate the OBS knob. The CDI needle shows your deviation from the selected course. Each dot represents 2° of deviation.
VOR navigation is tested on the PPL, instrument rating, and commercial pilot exams. Our question bank covers VOR tracking, intercepts, holding patterns, and more — with detailed explanations for every question.
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A VOR (VHF Omnidirectional Range) is a ground-based radio navigation station that broadcasts 360 radials extending outward from the station. Pilots use VOR receivers to determine their position relative to the station and navigate along specific courses.
A VOR radial is a magnetic bearing extending outward FROM the VOR station. There are 360 radials, one for each degree. If you are north of the VOR, you are on the 360 (or 000) radial. Radials are always defined as the direction FROM the station, regardless of which way you are flying.
The CDI (Course Deviation Indicator) shows how far you are from the selected course. Each dot equals 2 degrees of angular deviation. If the needle is deflected 3 dots to the right, the course is 6 degrees to your right. To return to course, turn toward the needle. Full-scale deflection means you are 10 degrees or more off the selected course.
The flag changes when you cross the line perpendicular to the selected OBS course that passes through the VOR. In practice, it flips from TO to FROM as you pass over or abeam the station relative to the selected course. The flag is independent of your aircraft heading — it only depends on your position relative to the VOR and the OBS setting.
The zone of ambiguity is the area roughly 90 degrees to either side of the selected OBS course where the TO/FROM flag shows OFF or a red striped flag. In this zone, the VOR cannot determine whether you should fly toward or away from the station on the selected course. The CDI reading is unreliable in this region.
Reverse sensing occurs when you fly toward the station with a FROM flag (or vice versa). The CDI needle deflects in the opposite direction of the correction needed. Always ensure the TO/FROM flag matches your intended direction of travel to avoid reverse sensing.
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