RVSM Aircraft Monitoring and How it Enhances Airspace Safety

With air travel and airspace usage demand increasing each year, the airspace rules are in transition to keep pace. Reduced Vertical Separation Minima (RVSM) was implemented in our airspace to accommodate increased air traffic and utilize enhanced safety features brought by modern aviation technologies. But what does RVSM do?

Separation change in RVSM Airspace Stratum

Safety Focus of RVSM Implementation

Any change to the airspace rules must keep the same or better target level of safety. There must also be a way to confirm that safety is maintained after the change.

Long-Term RVSM Monitoring

After RVSM was implemented, a recurring long-term RVSM monitoring plan was enacted to keep the airspace safe. Aircraft operating in RVSM airspace must complete an RVSM Monitoring flight test every 2 years or 1,000 flight hours (whichever period is longer) to maintain RVSM approval.

Altitude-Keeping System

The Altitude-Keeping System is the feedback control system that keeps the aircraft flying a specific pressure altitude as commanded by the flight crew. This control system displays the pressure altitude flown and that pressure altitude can be observed by both the flight crew (at the altimeter reading) and the Air Traffic Control (at the secondary surveillance radar of the aircraft reported MODE C).

Altimetry System

The Altimetry System is regulated by a barometric pressure sensor/transducer that translates ambient static air pressure at the port opening on the aircraft. This port translates ambient static air pressure into geopotential feet (pressure altitude) by means of ICAO Standard Atmosphere.

Monitoring the RVSM Airspace: Measuring the Aircraft Performance

The Regional Monitoring Agencies use the RVSM Monitoring tests to calculate the aircraft Altimetry System Error stability and error tolerance to provide evidence for safety. The RVSM Monitoring is a performance check on the effectiveness of Altimetry Systems installed to meet the RVSM certification and to certify as safe.

An RVSM Monitoring Tool independent GPS system antenna inside an aircraft

Total Vertical Error

We have already discussed the Altimetry System Error and how it covers the errors in the altimetry pressure altitude control system.

Flying a pressure altitude
GPS Height Estimate from the Target Air Pressure Flight Level

Error Values

If the aircraft values from the RVSM monitoring test results are withing the accepted tolerance range, the aircraft is considered in compliance for RVSM flight.

Determining the Aircraft Height-Keeping Performance

Questions on RVSM Monitoring?

CSSI, Inc. RVSM Services are proud to support the RVSM Monitoring mission around the world. Our team has experience supporting RVSM all aircraft types and have helped more that 20,000 RVSM Monitoring Flights succeed.

CSSI’s RVSM Monitoring Tool

Bobby Miller III Aviation Safety RVSM at CSSI, Inc.