Chamber At MCAS Miramar Simulates Low-Ox Environment

Some of the Navy and Marine Corps' toughest and stealthiest fighters play patty cake when they come to California's Marine Corps. Air Station Miramar, to train at the Aircraft Survival Training Center.

Reconnaissance Marines along side Navy SEALs play this childhood game in a simulation chamber that duplicates the conditions they would endure in a hypoxic environment -- an environment lacking oxygen.

The training familiarizes the service members with the way their bodies will respond at high altitudes where high pressure reduces the availability of oxygen.

Before entering the hypoxic environment, trainees sit in the chamber and breath 100-percent oxygen. This decreases the nitrogen concentration in their blood and helps prevent decompression sickness, Petty Officer 1st Class R. D. Nay, a corpsman at ASTC explained.

During the training the students are taken to a simulated altitude of 35,000 feet. The simulation represents the environment the trainees will experience when parachuting from extreme altitudes.

Once the service members reach 35,000 feet, the simulated drop in pressure begins and students fall at a rate of 5,000 feet per minute until they hit 25,000 feet. The drop in altitude effects the pressure in the chamber and the trainees remove their masks creating a controlled state of hypoxia.

As hypoxia takes over students lose the coordination and mental function needed to complete the simplest tasks such as playing patty cake with their neighbors or read color charts. As the time pressed on and with the low-oxygen saturation, the skin of the service members then began to turn blue and their motor skills decreased drastically.

Hypoxia can cause a person to feel euphoric, turn blue and lose the ability to perform simple actions. Often the individual suffering the symptoms of hypoxia is unaware of their mental and physical state. This can result in disaster in emergency situations at high altitudes. With this in mind, instructors at the chamber focus much of their training on teaching service members how to identify and treat hypoxia early on.

"I felt like I was doing good for a while," said Petty Officer 2nd Class Richard Munoz, a SEAL student. "I didn't even realize I was messed up until I tried focusing on the charts on the wall."

After approximately four minutes with no oxygen, the students descend to 18,000 feet to simulate night parachuting and navigating in a hypoxic state.

The room goes black. The red glow of flashlights illuminates darkness revealing small maps being held by shaking hands. The students focus their efforts on steadying their hands and eyes to properly identify a safe landing zone.

"There is a four-minute maximum that we can leave them without oxygen," said Navy Lt. Cmdr. Rebecca Bates, director, ASTC. "Between three and five minutes the service members become too impaired to treat themselves."

The goal is to train them to identify and self-treat hypoxia in the event they find themselves in an emergency situation at high altitudes, explained Bates. The strictly monitored time limit ensures the trainees are familiar with their reaction to a lack of oxygen, but not injured by the training.

"We want them all to feel the hypoxic symptoms, explained Bates. "The symptoms are not always the same so some people react different."

It's not until the oxygen masks return to the faces of the trainees that their eyes lose their dopey glaze and the service members regain control of their limbs. With the oxygen flowing again, a light goes on in the minds of the students as they realize the significance of this often comical, yet potentially lifesaving training.

"It was some good training and I learned a lot," said Munoz. "At first, it was a bit scary. Once we got used to the feeling our class room knowledge kicked in. This training will help out with situational awareness when it is the real deal.

The ASTC at Miramar is one of two in California. The other at Naval Air Station Lamoore, houses up to 4,000 students per year for various types of aviation survival training.

(ANN salutes Lance Cpl. George J. Papastrat, MCAS Miramar)

FMI: www.miramar.usmc.mil