Peterson AFB high altitude chamber prepares aircrews for flight

by Senior Airman Rose Gudex
21st Space Wing Public Affairs

12/15/2015 - PETERSON AIR FORCE BASE, Colo.  -- Whether a pilot in training or a veteran taking a refresher course, service members from all around the Unites States come to Peterson Air Force Base to experience the high altitude chamber and learn how to recognize the effects lack of oxygen has on their body.

The Aerospace and Operational Physiology Flight offers training for personnel to learn and understand the human challenges inherent to military operations and increase the overall readiness and mission effectiveness.

"We train aircrew about how the human body is affected by flight," said Maj. Nathan Maertens, 21st Aerospace Medicine Squadron aerospace and operational physiology flight commander. "The reason for the high altitude chamber is because at high altitude there is not a lot of oxygen and there's less pressure. We want them to experience that in a safe training environment."

Any operational aircrew and special operations personnel must go through the training to be able to recognize how their body reacts to low oxygen should their pressurized aircraft become unpressurized at a high altitude, he said. Those needing training must be initially qualified and receive a refresher course every five years.

At the beginning of the course, students have a classroom session going over a variety of topics, depending on what their course is based on, said Airman 1st Class Ben Clark, 21st Aerospace Medicine Squadron aerospace and operational physiological technician.

"Everyone gets the same initial training," he said. "Everyone is going to run through the chamber the first time and get a rapid decompression. The basic information will be the same across the board, but then we tailor information specifically to each mission."

Topics covered include cognitive performance, situational awareness and shortcomings on decision making, spatial disorientation and how a person's body can lie to them while in flight, Maertens said.

"We also talk about the physical limitations one may have to deal with, whether that be fatigue due to a high ops tempo or (failing) to appropriately prepare for the mission and skipping breakfast," he said. "All those different things can have an effect on how we perform."

To begin, students are fitted with a mask and file into the high altitude chamber, which is essentially a metal box that the air gets pumped out of to simulate the low oxygen and decreased pressure found at high altitudes, said Clark.

Students first get taken up to a simulated 1,000 feet to get the feel of the chamber and brought back to ground level while three AOP technicians watch closely. Then, the technician acting as the crew chief controlling the vacuum and altitude of the chamber takes the students up to 25,000 feet. The instructor speaks over a headset about what each student could be feeling and what to look for as the altitude gets higher and the monitor records visible reactions students have and time spent at the high elevation.

Maertens said students remove their masks and are off oxygen briefly while at 25,000 feet to help students get a feel for how their body reacts to the hypoxic environment.

"They can recognize, 'wow, I'm not feeling quite right. My pressurization system looks like it's working right, but something's not right,'" he said. "They can start cross checking other things and determine the origin of the problem."

A small inverted flask in a beaker filled with red fluid sits next to the window as a visual representation of the pressure changes taking place, Maertens said.

"As we ascend in altitude, the pressure decreases and therefore the additional pressure inside your middle ear wants to correlate with the pressure outside. Then the additional pressure will vent out, like the bubbles we saw," he said. "Conversely, on descent, we have relatively high pressure outside us and low pressure inside. That's what draws the fluid up into the beaker."

The AOP high altitude chamber is one of only 11 chambers in the Air Force. With a flight of only 14 Airmen to train aircrew on high altitude and the dangers of hypoxia, Clark said roughly 50 service members come through each week to be qualified.

The family-like unit works hard to complete a mission essential to ensuring all service members are fully aware of the effects their bodies experience at high altitudes.

"I get a lot out of this job," Clark said. "This is what I love. It's awesome getting to keep people out of really serious mishaps. That means a lot to me."