Dangers at high altitudes, preparing fliers for the worst

  • Published
  • By Airman 1st Class Ryan Lackey
The KC-135 Stratotanker and the C-130 Hercules operates at altitudes over 25,000 feet, an environment that presents aircraft crews and free-fall parachutists with environmental challenges and subsequent dangers not found at the ground level, such as a thinner atmosphere that makes it harder to breathe and sub-zero temperatures. All Airmen that operate in high altitudes undergo specialized training to prepare them for their unique workplaces.

Hypoxia Training:

Aircraft pressurize their interiors for the comfort and safety of the crew and passengers. An aircraft that loses interior pressure can quickly put fliers into a state of hypoxia, or oxygen deprivation, a life-threatening condition that pilots and free-fall parachutists are trained to recognize and signal for help if they experience its symptoms.

“Not getting enough oxygen to your lungs causes hypoxia,” said Tech. Sgt. Oscar Pena, 92nd Aerospace Medicine Squadron physiology technician. “It's a condition that can put a jumper or aircrew member in danger of passing out within seconds.”

All pilots, aircrew and jumpers are required to undergo simulations in a hypobaric or altitude chamber during initial training before qualifying to fly or jump. Renewal of this qualification is required every few years.

“Rather than send our crews on costly training deployments, we have specialized equipment to keep them ready to fly right here at Fairchild,” Pena said. “This equipment requires only one instructor versus nine to crew an altitude chamber, so it saves a lot of time and money.”

The 92nd AMDS uses two machines to train Airmen on the effects of hypoxia: the Reduced Oxygen Breathing Device and the Hypoxia Familiarization Trainer.

The breathing device connects directly to an oxygen mask and can physiologically put an Airman at any simulated altitude, allowing them to experience hypoxia symptoms in a safe environment on the ground.

The hypoxia trainer builds upon the breathing device by letting pilots and aircrew experience hypoxia symptoms while attempting to operate a flight simulator.

“It makes it more real to do it this way,” said Capt. Brian Pillers, 384th Air Refueling Squadron KC-135 pilot. “When you’re sitting in the simulator with the mask on and attempting to fly the aircraft, it’s making you hypoxic and forcing you to learn how to recognize what those symptoms feel like.

“This is a much more effective training environment than an altitude chamber,” Pillers added.

Anyone unable to get sufficient oxygen may experience air hunger or gasping for breath, increased heart rate, diminished visual acuity, cognitive difficulty and unconsciousness. Oxygen deprived pilots may find their instruments impossible to read, become confused or unresponsive.

“Lack of oxygen will also affect your vision and change how you perceive things,” Pena said. “Colors will look different, objects are darker and will lose detail, and you may lose peripheral vision. Eyes are directly connected to the brain, so your vision diminishes when the brain is deprived of oxygen.”

The atmospheric pressure at sea level makes breathing easy as the pressure pushes air into our lungs, but at 30,000 feet, it’s just under half as much pressure, forcing the body to work harder by gasping for air.

“Your body metabolically doesn't feel the same way at high altitudes,” said Master Sgt. Eric Icenhower, 141st Air National Guard Survival Evasion Resistance and Escape liaison. “You try to breathe and stay calm, but you feel like you have a cold that affects your whole body, making you weak. When I tried to exert myself, that feeling became overwhelming and my focus went out the door. My mind just blanked and I couldn't help but space out.”

Knowing how to deal with physical symptoms that may cause an Airman to lose control during flight is a critical skill that can save a mission, an aircraft, but most importantly: it can save lives.

“There are procedures for pilots who feel hypoxic to follow, guidelines that allow them to abdicate control to a co-pilot, assess their condition and recover,” Pena said. “Symptoms can be helped by getting oxygen, but hypoxia will ultimately win every time. It doesn't matter how fit you are or what preparations you do on the ground, nobody can function for long without oxygen.”

Night Vision Training:

Night missions are a common working condition that presents specific hazards for pilots and parachutists, as low visibility can affect depth perception, induce vertigo and cause the aircrew to miss vital details. Nighttime para-jumpers run the risk of colliding with each other and pilots may lose sight of the ground in dark or foggy conditions.

Alongside hypoxia training is the night vision training room, a facility that gives Airmen the opportunity to familiarize themselves with night vision equipment and test its use in a number of simulated environments.

“It's a big benefit for us to be able to see the differences in using night vision goggles in all kinds of different situations, because it's not always the best equipment to use or may be rendered ineffective by changing conditions,” Icenhower said. “SERE trainees need to know what people and environments look like when using NVGs, so they know how to remain undetected when an enemy is using them.”

While NVGs allow Airmen to see better in low-light environments, they do have limitations. All aircrew will use night vision equipment at some time, so the training provided is to acquaint aircrews and jumpers with what they can expect when using it.

“It is an outstanding tool,” Pena said. “However, many think that it can work in total darkness or in poor weather conditions, so this training helps Airmen judge how best to use it.”

From using simulators to help pilots and aircrew recognize hypoxia to gaining experience working with NVGs in low-light conditions, the 92nd Aerospace Medical Squadron provides vital training that helps keep Fairchild’s Finest safe and allows us to continue fulfilling Rapid Global Mobility … Now.