Welcome to IVAO Tunisia

RVSM airspace was introduced throughout Europe in January 2002. It has also been implemented in North America, South America, Australia, Middle East, Africa, Parts of Asia and the Atlantic and Pacific Oceans.

RVSM means Reduced Vertical Separation Minima - or in plain english the reduction of the vertical separation required between FL290 and FL410 from 2000ft to 1000ft. By doing this you double the amount of airspace available, therefore doubling the traffic capacity. With the skies getting busier and busier every day the need for more room has become more and more important.

In the real world aircraft must have the following equipment aboard to be RVSM certified and therefore take advantage of the reduced separation minimum:

  • Two primary altitude reporting systems;
  • One automatic altitude-keeping device;
  • One altitude-alerting device.
  • In addition, while changing altitudes, the altitude holding device must not overshoot an assigned level by more than 150 feet.
  • Also, to gain certification for RVSM, each aircraft must overfly a stationary Height Monitoring Unit (HMU) or a portable Ground Monitoring Unit (GMU) unless flight test evidence can be supplied to the regulator that the airframe is compliant with Altimeter System Error (ASE) targets.

Aircraft who do not meet the standards are excluded from RVSM airspace except for the purpose of climbing or descending to/from the CVSM airspace above FL410. (Exceptions do exist though, see bottom of page for complete listing.)

In the real world this was a costly affair for operators who still had older aircraft in their fleet. On IVAO there isn't much to it, as any aircraft can be considered RVSM, or non-RVSM. There are however a few important procedures for pilots and ATC to follow. They are detailed below.

Altitudes

Pilots flying through RVSM airspace continue using the Odd-East / West-Even rule up to FL410, after which the airspace becomes CVSM.

Use the following table for reference:

RVSM airspace (the new way)
West track (180°-359°)
Even Altitudes
East track (000°- 179°)
Odd Altitudes
4,000 ft
6,000 ft
8,000 ft
10,000 ft
12,000 ft
14,000 ft
16,000 ft
FL 180
...
FL 280
-------------
FL 300
FL 320
FL 340
FL 360
FL 380
FL 400

FL 430
FL 470
FL 510
...
5,000 ft
7,000 ft
9,000 ft
11,000 ft
13,000 ft
15,000 ft
17,000 ft
FL 190
...
FL 290
-------------
FL 310
FL 330
FL 350
FL 370
FL 390
FL 410

FL 450
FL 490
FL 530
...
CVSM airspace (the old way)
West track (180°-359°)
Even Altitudes
East track (000°- 179°)
Odd Altitudes
4,000 ft
6,000 ft
8,000 ft
10,000 ft
12,000 ft
14,000 ft
16,000 ft
FL 180
...
FL 280
-------------
FL 310
FL 350
FL 390

FL 430
FL 470
FL 510
...
5,000 ft
7,000 ft
9,000 ft
11,000 ft
13,000 ft
15,000 ft
17,000 ft
FL 190
...
FL 290
-------------
FL 330
FL 370
FL 410

FL 450
FL 490
FL 530
...

Changes to cruise direction from the old system to the new RVSM system are highlighted in red.

Pilot Guidelines

All pilots operating within RVSM airspace are to comply with the following guidelines:

  • Pilots flying RVSM certified aircraft are expected to file altitudes appropriate for the direction of flight in compliance with the previous table.
  • The equipment suffix W shall be filed in the flight plan to indicate RVSM certification.
  • Autopilot must be used to maintain altitude in level cruise flight. Manual trimming of the aircraft is not acceptable. If the autopilot does not work or the altitude hold mode is known to be inaccurate, the aircraft will be considered non-RVSM, and therefore not allowed into RVSM airspace. The equipment suffix "W" is not to be used on such aircraft.
  • If a pilot notices his aircraft is unable to accurately maintain altitudes with the autopilot altitude hold he/she is to consider the aircraft as not up to RVSM standards and notify ATC at once. This applies regardless of whether the aircraft is already in, or cleared to enter RVSM airspace. ATC may instruct pilots of such aircraft to leave RVSM airspace if traffic requires.
  • Pilots are to report any encounters with turbulence greater than moderate. By its nature, severe turbulence means that control of the aircraft is affected, and RVSM procedures can no longer be maintained.

ATC Guidelines

All controllers operating positions involving RVSM airspace are to follow the following guidelines:

  • All aircraft having filed /W equipment suffix will be considered RVSM certified and equipped, unless there it is apparent that the aircraft is unable to hold altitude with reasonable accuracy.
  • Aircraft not having filed /W equipment suffix, will not be cleared to enter RVSM airspace except for those aircraft meeting the conditions described in the exceptions listed below.
  • Aircraft operating in RVSM Airspace who indicate an inability to maintain altitude correctly shall be considered non-RVSM compliant. Separation for such aircraft shall be immediately increased to 2,000 feet vertically, and the aircraft shall be cleared to climb or descend out of the RVSM airspace as soon as practicable. Aircraft who are unable to make destination due to fuel requirements at lower levels will not be required to descend below RVSM airspace, but 2000ft separation will have to be maintained at all times. The idea is to remain within the rules of RVSM while not creating a fuel shortage for the aircraft involved. It is essential to pass this information to adjacent sectors/units.
  • Use of altitudes inappropriate to direction of flight (wrong-way) in RVSM airspace remain the same as outside of RVSM airspace. Aircraft cruising at such altitudes should be cleared back to correct altitudes as soon as practicable.
  • If an aircraft reports greater than moderate turbulence, use of 2,000 feet vertical separation will be required. Immediate action must be taken to provide another form of separation, including changing of altitudes, use of speed control, or re-routing.

Exceptions

There are a few exceptions which may allow a non-RVSM certified aircraft to operate with RVSM exclusionary airspace. For those who do get clearance into it, the following rules apply:

  • RVSM certified aircraft will receive priority for altitude assignment over non-RVSM aircraft. (see example above)
  • Vertical separation of 2,000 feet will be maintained between non-RVSM aircraft and all other aircraft.
  • Aircraft wishing to climb or descend through RVSM airspace are to be granted clearance provided they do not level off within RVSM airspace, should maintain a normal rate of climb or descent (no cruise climbs/descents allowed).
  • Aircraft used by military, police and customs services are exempt from RVSM certification requirements, do not require advance approval, and will be provided with 2,000 feet separation from all other aircraft in RVSM airspace.

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