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Introduction to RVSM

Welcome to the sixth installment in our Air Medical Resource series about the Air Ambulance. One acronym you may hear brought up often in regards to air medical services is RVSM. It may sound like an esoteric medical acronym, but it actually has to do with the ability of an aircraft to fly within optimal airspace. Read on to learn more about RVSM and how it relates to air ambulances.

What is RVSM?

RVSM stands for Reduced Vertical Separation Minimum. It is essentially the reduction of the amount of vertical distance required between aircraft flying between 29,000 ft – 41,000 ft and from 1000 ft – 2000 ft under normal circumstances. RVSM increases the number of aircraft that can safely fly within this particular part of airspace. This reduction is made possible because modern equipment is far more accurate and reliable when it comes to calculating distances than the older altimeters.

RVSM and Air Ambulances

787 cockpit

Air ambulances that have been certified for RVSM can fly more optimum profiles; thereby using less fuel on long-distance transports. Transports conducted within this optimal altitude range also take less time.

For safety reasons, to be permitted to fly within the more fuel-efficient RVSM airspace, an air ambulance needs to be equipped with certain certified altimeters and autopilots. Generally, an air ambulance without RVSM certification is required by the FAA to fly above or below RVSM designated airspace.

Air ambulance services must also receive specific approval from the state to operate aircraft in RVSM airspace, unless the aircraft belongs to the state (such as a rescue medevac helicopter operated by the military or a police department). These latter types of aircraft are still requested to be adapted to RVSM requirements as much as possible.

On a long distance medical transport, an aircraft will not only use less fuel if it is allowed to fly in RVSM airspace, but will therefore need to make fewer fuel stops (especially important in the case of international air medical transports). Fuel stops are time consuming, and can be frustrating for patients and family members who are eager to reach the destination facility.

Reduced vertical separation minimum - Learjet 60

In general, operating at the higher RVSM altitudes rather than at low altitude will produce an overall smoother flying experience with less turbulence. This is not a hard and fast rule, but flying within RVSM airspace will generally result in less “chop.”

Experiencing strong turbulence is uncomfortable and can be very stressful for patients and families during an time when they already have enough on their minds. Thus, being able to operate within RVSM airspace directly affects the comfort level of the patient during the transport.