RVSM refers to Reduced vertical separation minima or minimum.
It is defined as the reduction of the Vertical Separation Minima (VSM), from 2,000 feet to 1,000 feet, between flight level 290 (29,000 ft) and flight level 410 (41,000 ft).
To enter such airspace, there are a few requirements that need to be met, particularly concerning RVSM equipment requirements.
What Equipment Is Needed for RVSM Airspace?
The required equipment to operate in RVSM airspace includes:
- 2 Independent Altitude Measuring Systems
- A secondary surveillance radar (SSR) Altitude Reporting Transponder
- An Altitude Alert System
- An Automatic Altitude Control System
Is Autopilot Required in RVSM Airspace?
Yes, autopilot is required in RVSM airspace, which is what an Automatic Altitude Control System refers to.
It must also be operable from either of the two independent altitude measurement systems.
Is TCAS Required for RVSM?
A traffic collision avoidance system (TCAS) is not required to enter RVSM airspace.
The only requirement is that if TCAS II is already installed, it must be updated to TCAS II Version 7.0 or later.
What Error Tolerance Is Allowed for Required RVSM Equipment?
The error tolerance for an Altimetry System Error (ASE) is 75 m or 245 ft. These RVSM altimeter requirements concern the difference between the displayed pressure altitude and actual altitude.
The error tolerance for a Total Vertical Error (TVE) is 90 m or 300 ft. This is the difference between the assigned pressure altitude and actual altitude.
The error tolerance for an Assigned Altitude Deviation (AAD) is 90 m 300 ft. This is the difference between the altitude assigned by ATC and the altitude provided by the onboard equipment.
As long as the expected error tolerance is within range, an aircraft can safely fly within RVSM airspace.
What Are the Rules Concerning RVSM Monitoring and ADS-B Out?
The FAA requires every aircraft that has ADS-B installed to perform a separate RVSM Monitoring flight test. This must be done 24 months prior to installation to remain in compliance.
After installation, a separate RVSM Monitoring flight test is still required every 24 months, or if it’s been 1,000 flight hours since last monitored.
What Happens if the Equipment Fails Prior to Entering RVSM Airspace?
If any of the equipment fails prior to entering RVSM airspace, a pilot should request new clearance and not enter the airspace.