Definition
The lowest altitudes, expressed in feet above mean sea level (MSL), at which an air traffic controller may radar-vector an IFR aircraft within a specified airspace sector around a radar facility. MVAs provide required obstacle clearance (typically 1,000 feet over flat terrain and 2,000 feet over designated mountainous terrain) and are depicted on a controller's MVA chart. They are not published on pilot charts.
Plain English
The lowest height a controller is allowed to send you to when steering you with radar headings in a given area. The altitude is set high enough to keep you safely above terrain and obstacles in that sector.
Context Anchor
Seen in radar control and TRACON discussions, especially when a controller gives headings and altitudes to aircraft near an airport.
Derivation
"Vector" comes from the Latin vehere, meaning "to carry." In aviation it refers to a heading the controller assigns to carry the aircraft along a desired track. A minimum vectoring altitude is therefore the lowest altitude at which the controller is permitted to carry the aircraft on assigned headings.
Why Pilots Care
MVAs let controllers give more direct routes and lower altitudes than published navigation altitudes while still protecting the aircraft from obstacles.
Analogy
Think of an MVA chart like a floor map for a building with different minimum safe floor levels in different rooms. The safe lowest level changes depending on where you are.
Intuition Check
Minimum does not mean “safe everywhere nearby.” An MVA applies only inside its defined area and only for radar vectoring by ATC.
Example Sentence 1
Approach descended us to 3,000 feet, which was the minimum vectoring altitude for that sector until we were established on the final approach course.
Example Sentence 2
Because the aircraft was inside the MVA sector, the controller could vector it at 2,300 feet without conflict with terrain.