What Is RVSM? Definition & Meaning in Aviation
RVSM (reduced vertical separation minimum) allows aircraft to fly 1,000 feet apart vertically, instead of 2,000 feet, between about 29,000 and 41,000 feet.
In plain language
It doubles the number of usable cruising altitudes, so more aircraft can use busy airways. Aircraft and crews need special approval to fly in RVSM airspace.
Example
Aircraft crossing Pakistan between Europe and Asia fly at assigned flight levels spaced 1,000 feet apart.
Why it matters
RVSM allows more aircraft to use busy airways, which is essential over crowded corridors such as those crossing Pakistan. Aircraft without RVSM approval must fly below or above the band.