Definition
An aircraft installation containing two independent VOR receivers, each with its own antenna (other than the dual system of antennas), permitting simultaneous tuning of the same VOR ground station and direct comparison of the two indicated bearings as a check of receiver accuracy.
Plain English
Two separate VOR units in the same aircraft. Because they work independently, you can tune both to the same station and compare what each one shows. If they agree closely, you know both are working correctly.
Context Anchor
Seen during VOR receiver accuracy checks before using VOR navigation for instrument flight.
Derivation
Dual' comes from Latin 'duo' meaning 'two.' In this term it signals that there are two complete, independent VOR systems in the aircraft — not one system with two displays.
Why Pilots Care
Confirms that both VOR receivers are accurate enough for reliable navigation.
Intuition Check
A dual system VOR does not mean one extra-accurate VOR unit. It means two separate VOR units whose indications are compared against each other.
Example Sentence 1
Before departing IFR, the pilot used the aircraft's dual system VOR to perform the required accuracy check, confirming the two receivers agreed within 4°.
Example Sentence 2
The dual system VOR check showed the bearings agreed within two degrees so the equipment was considered serviceable.