LAUGHLIN AIR FORCE BASE, Texas -- Being above 10,000 feet in altitude can have unpredictable effects on the human body; some people get delirious, others get nauseous, and some experience hot or cold flashes. Knowing how a pilot’s body will react to changes in altitude is a crucial part of pilot training.
This is where the 47th Operations Support Squadron (OSS) hypobaric chamber comes into play, allowing pilots and aircrew to experience the sensation of low oxygen in a safe environment on the ground. This training is mandatory for pilots and aircrew and not available at every base.
While in the chamber, aircrew and pilots will begin by testing their equipment, making sure the mask seals to their faces and does not leak air. Instructors will go to each trainee, ensuring a proper fit before starting the denitrification process where excess nitrogen is purged from the body’s bloodstream.
Then chamber technicians will begin taking the chamber “up” to altitude, reaching as high as 25,000 feet in simulated altitude. Technicians will raise and lower the chamber for various tests, allowing participants to practice the Valsalva maneuver to equalize the pressure in the pilots ear canals, swapping to emergency oxygen, and practicing paper tests while under the effects of oxygen deprivation. During these tests, students in the chamber are closely monitored by observers that are in and outside the chamber, helping them correct if needed.
“The mission of aerospace physiology with the chamber is to teach pilots about hypoxia and what they might feel when they go up in altitude,” said Airman 1st Class Bridgette Counter, 47th OSS aerospace physiology technician. “We want them to recognize the symptoms and recover.”
Recovering students must realize they are under the effects of oxygen deprivation, reapply their mask, and turn their oxygen up to 100% before they are forced to undertake these actions. Instructors guide these procedures in and out of the chamber and monitor their overall status.
During the training, aircrew and pilots also practice for other situations, undergoing night training in the chamber, where chamber operators will block out the windows and turn off the lights in 0and around the chamber, allowing members inside to get used to operating in darkness.
Once this task is completed, trainees move on to the final task, training for a rapid decompression emergency.
Chamber operators will remove students from the main chamber and seal the door, which will allow the chamber to rise to 17,500 feet. Students are then brought into the smaller secondary chamber which is closed and brought up to 2,000 feet. While inside, an instructor will go over the procedures for rapid decompression, during the instructions they will say a key phrase, alerting the lock operator on the outside of the chamber to fire a switch.
When the switch is thrown, fog rapidly fills the chamber due to the pressure equalizing. Students must then rapidly attach their breathing apparatus and turn their oxygen flow up to 100 percent.
“It’s important that these pilots get to know their hypoxia symptoms in the chamber,” Airman 1st Class Crystal Arrendondo, a 47th OSS aerospace physiology technician, said, “This is a controlled environment, so they know when they are going to get hypoxic. We tell them to drop their masks and then they know to pay attention to their body and to ask ‘what am I feeling right now?’ They can then use that when they’re flying to rely on recognizing those symptoms they felt in the chamber.”
With pilots and aircrew now knowing their own symptoms they can continue to the next stage of their training and get hands-on experience in the aircraft.
Technicians like Counter and Bridgette help prepare pilots and aircrew for their missions. These missions will develop combat ready Airmen and the best pilots in the world.