Newswise — It only takes a few seconds for the heads-up — if you know what you’re feeling.And in an airplane, those few seconds spell the difference between getting back safely or not.

We’re talking decompression, one of the things the flight attendants tell you about when they’re demonstrating the use of those bright yellow oxygen masks.

“It can happen real fast,” said Warren Jensen, a flight surgeon and a Chester Fritz Distinguished Professor of Aviation in the University of North Dakota's John D. Odegard School of Aerospace Sciences.

Jensen also runs the school’s “altitude chamber” where students learn to deal with decompression and hypoxia, when the body is deprived of oxygen as an airplane loses cabin pressure.

“You want to deal with it before the hypoxia impairs you,” said Jensen, who in 2012 ran more than 200 altitude chamber classes for 850 students. “The goal of our altitude chamber training here is to teach students to recognize the symptoms of hypoxia — and they’re different for each person — and to deal with them immediately.”

In an aircraft, decompression-induced hypoxia at high altitude can be fatal, as was likely the case with a Lear 35 that crashed in South Dakota with famed golfer Payne Stewart, friends and crew aboard. As experts such as Jensen attest, hypoxia can quickly lead to confusion and blackout, but not if the crew has been trained to recognize what’s going on and takes appropriate action immediately.

The altitude chamber — a unique asset at UND — is used for both aviator training and research, including Fortune 500 corporate pilots. It’s capable of simulating altitudes in excess of 80,000 feet and is used to teach flight crews the physiological effects of high-altitude flight in a safe training environment. Subjects presented in the Aerospace Physiology courses include hypoxia, hyperventilation, cabin decompression issues, visual and spatial disorientation, and several other related topics.Altitude chamber training works. Ask Dan Fluke.

An airline pilot and 2009 graduate of UND Aerospace, Fluke always knew he wanted to fly. He also knew he wanted the best training available and all the safety courses available.

This is why he enrolled at UND and, as part of his training, took Jensen’s altitude chamber course.

Recently, while flying a commuter jet with 40 passengers aboard, Fluke noticed a familiar and ominous sensation: a numbing feeling, a kind of tingling, that he recognized only because of his UND altitude chamber training.

“I knew what it was right away,” said Fluke, who also runs a business in Florida, writing and publishing aeronautical training guides. “That sensation is what triggered me to look at the indicators, which told me that the aircraft, in fact, was depressurizing. It rang a lot of bells for me, back to my training at UND. I went for my (oxygen) mask. We had to make a quick decision to make a descent to the closest airport.

“Basically, what you get is a sensation happening in your core progressing outward toward your arms. You know to go for the mask first rather than fumble with the instruments or worry about other things. You want to get ahead of the situation.”

Jensen, himself a UND alumus and Air Force veteran, earned a master’s degree in aerospace medicine from Wright State University in Dayton, Ohio, in 1993. Today, he serves as UND Aerospace director of aeromedical research.

Jensen’s research includes human flight performance, decision-making in emergency settings, and oxygen delivery systems. He also teaches courses in human factors in aviation and aerospace physiology.

Unmanned Aircraft Systems (UAS), for which the aerospace program at UND has become a world leader, is another area in which Jensen has begun to collaborate with others on campus.

Jensen is an academic advisor for 25 to 30 aviation undergraduate and graduate students. He also is the aviation medical advisor to students, flight instructors and faculty for medical certification issues.

The UND altitude chamber is run by a team that, in addition to Jensen, includes Joe Schalk, with 47 years of chamber experience, and Steve Martin — both Air Force altitude chamber training veterans. Also, Janelle Johnson, a finance associate for the UND Aerospace Foundation, works part-time with the altitude chamber crew.

Fluke previously worked at recruiting events and in other capacities with assistant dean Ken Polovitz and academic advisors Kim Higgs and Amy Sand, all with UND’s John D. Odegard School of Aerospace Sciences.

But among his most valued experiences at UND, Fluke notes, were the critical minutes of instruction with a flight surgeon and crew in a big steel box in Odegard Hall.

“I called Doc a couple of days after my decompression incident and thanked him,” Fluke said. “The first signal I felt in that airplane was what I’d felt in Dr. Jensen’s class.”