Hypoxia demonstration an eye

Mar 22, 2024

By Frederick Johnsen · August 31, 2023 · 1 Comment

General aviation pilots at EAA AirVenture Oshkosh 2023 volunteered to sustain oxygen deprivation, turn blue, and emulate barely-sentient zombies in the interest of flight safety — their own flight safety.

The opportunity came in the form of a Plexiglas box that seated about five pilots, plus an FAA monitor. Called the Portable Reduced Oxygen Training Enclosure (PROTE), it’s an ingenious little room that has pumps to evacuate oxygen down to about 7% and replace it with nitrogen, simulating an altitude of 25,000 to 27,000 feet without the pressure changes associated with old-school iron altitude chambers.

Because there is no pressure variable, the introduction of nitrogen into the body does not produce negative effects like decompression sickness, FAA instructor J.R. Brown explains. He is part of the FAA’s Civil Aerospace Medical Institute (CAMI), an organization that provides, among other things, medical research and education of use to pilots.

Especially for GA pilots, the portable set-up offers a realistic simulation of oxygen deprivation as a gradual phenomenon, not the rapid-decompression bang that traditional chambers produce.

Within seconds of entering the box, pilots are beginning to exhibit reduced capabilities associated with oxygen deprivation. Vision degradation and mild headaches are frequently felt first.

Knowing your symptoms is a life-saver. The FAA team gives each pilot a clipboard on which they write down their symptoms as they feel them.

Brown tells the pilots to look at each other to see if anyone shows signs of turning blue — cyanotic — as their access to oxygen wanes. He says this can be a way for people in multi-seat aircraft to detect the presence of hypoxia by seeing it in others.

And then the zombie games begin. With oxygen masks at the ready, the unmasked pilots are asked to perform simple math tasks.

“Reciprocal heading from 125. Give me that heading,” Brown asks over a PA system.

Some of the pilots feel symptoms quickly and don their oxygen masks, which quickly return their blood oxygen levels to normal. Others soldier on without masking until their answers no longer make sense and their cognitive functions slow to a halt. Some of these pilots need to be helped putting their masks up to their faces.

The lessons are evident. Hypoxia is an insidious phenomenon that will rob anyone of the ability to function.

Aime Fauchon, a 10-year VFR pilot, who flew to AirVenture from Edmonton, Alberta, said he was having a harder time concentrating the longer he went unmasked in the simulator. He compared it to the mental fog that comes at the end of a four-hour exam.

Towards the end of the session, he was performing tasks requested by Brown that he did not remember after leaving the portable chamber. Fauchon commented on the dangers of “hypoxic amnesia.”

Seated next to Fauchon was college senior Dana Rose from Ohio, where she is working toward a career as a commercial air cargo pilot. She experienced a dizzying lightheadedness, noting that she found the session helpful.

The ticket for admission to the hypoxia demonstrator is a current medical certificate. The FAA takes its box on the road, supporting about a half-dozen events a year across the country.