• In the late 50ís, due to the reduced precision of pressure altimeters as a result of increased altitudes, it was concluded that the prescribed 1000-ft Vertical Separation Minimum (VSM) had to be increased above a given flight level.
  • In 1960, an increased VSM of 2000 ft was established between aircraft operating above FL 290, except where regional air navigation agreements prescribed a lower level.
  • In the late 70ís, in face of increasing fuel costs and growing demands for a more effective use of available airspace, ICAO began a complete program of studies to examine the possibility of reducing the 2000-ft VSM applied above FL 290 to 1000 ft.

Reduced Vertical Separation Minimum (RVSM)

The concept of RVSM has been introduced and applied to the airspace between flight level (FL) 290 (29,000 feet) and FL 410 (41,000 feet), inclusive. In this regard, the vertical separation minimum (VSM) between aircraft has been reduced from 2,000 feet to 1,000 feet as shown below:

While the airspace capacity has almost doubled, an aircraft flying in the RVSM airspace could also operate at its optimum flight level, enabling fuel efficiency as well as reducing flight delay resulting in less operational costs for aircraft operator. The RVSM airspace is considered to be the special qualification airspace. The operator and aircraft used by the operator need to be inspected and approved by the State Civil Aviation Authority before conducting flight in the RVSM airspace.

RVSM Current Implementation

The following map shows the current RVSM implementation worldwide.