Definition
An airspace standard that allows aircraft to be separated vertically by 1,000 feet, instead of the previous 2,000 feet, between flight levels FL290 and FL410 inclusive. To operate in RVSM airspace, both the aircraft and the operator must be specifically authorized, and the aircraft must meet strict altitude-keeping performance and equipment requirements.
Plain English
A rule that lets approved aircraft fly only 1,000 feet apart vertically in the high-altitude band where they used to need 2,000 feet apart. It doubles the number of usable cruise altitudes up high, but only properly equipped and approved aircraft are allowed in.
Context Anchor
You will see RVSM in high-altitude flight planning, IFR clearances, aircraft equipment requirements, and discussions of operations above flight level 290.
Derivation
The name describes itself in plain terms: 'reduced' (the spacing was made smaller), 'vertical separation' (distance between aircraft measured up and down), and 'minimum' (the smallest legally allowed gap). The rule was introduced because more accurate altimeters and autopilots made the older 2,000-foot buffer unnecessary, freeing up more cruise levels for traffic.
Why Pilots Care
It creates more usable flight levels in busy high-altitude airspace, increasing capacity and reducing delays without reducing safety.
Grounding Statement
In RVSM airspace, two approved aircraft can safely use closer altitude spacing because their altitude-measuring and holding systems meet tighter standards.
Intuition Check
RVSM does not mean reduced safety margin. It means the required vertical spacing is reduced only for aircraft and operators that meet specific approval and equipment standards.
Example Sentence 1
The aircraft is RVSM-approved, so we can file for FL350 on tonight's flight.
Example Sentence 2
RVSM airspace allows more flights to use efficient altitudes between the East and West coasts.