High-altitude hypoxia likely caused the crash of a small private plane (N900KN) last Friday, according to the North American Aerospace Defense Command (NORAD). The flight was en route from Rochester, New York, bound for Naples, Florida.
#NORAD F-15 fighter jets are currently escorting an unresponsive small aircraft over the Atlantic, possible hypoxia. More to follow.The Federal Aviation Administration (FAA) says the plane became unresponsive and failed to respond to air traffic controllers for several hours. Bloomberg reports the plane was flying at 25,000 feet (7,600 meters), where oxygen is more thin than at sea level. Such an altitude can cause hypoxia.
— NORAD & USNORTHCOM (@NoradNorthcom) September 5, 2014
Hypoxia is a fancy term for low (hypo-) oxygen (-oxia) in the body. Hypoxia can effect your entire body (like at high altitude) or just a part (like if you had a tourniquet). Your brain is particularly susceptible to hypoxia and can only function for a couple of minutes once hypoxia sets in. Because more brain activity causes more oxygen demand, when your brain detects hypoxia, it shuts down to conserve energy and avoid serious brain damage.
Your brain needs oxygen to function. Brain cells are particularly vulnerable to a lack of oxygen [hypoxia]. Without it they can die off and cause permanent brain damage. When a brain goes without oxygen [hypoxia] for too long, it can stop you from breathing, or may stop your brain from working altogether.Hypoxia resulting from a cabin pressure leak likely caused the crash of N900KN.
Low cabin pressure can cause hypoxia by slowly leaking oxygen. Normal air is about 20 percent oxygen. At high altitudes, air is less dense and you become hypoxia because each breath contains less oxygen. High altitude hikers wear oxygen and plane cabins are pressurized to avoid such hypoxia.
According to a former FAA chief, hypoxia resulting from decreased cabin pressure is pernicious,
The problem is the insidious undetected loss of cabin pressure where it just creeps up and pilots doze off before they realize what's happening[.]Detecting hypoxia in yourself is tricky because its onset is slow and relatively undetectable. According to CNN,
In the beginning, pilots may experience an increase in the rate at which they breathe. They also may feel lightheaded or dizzy. Eventually, they will start to lose coordination. They will experience tunnel vision and their judgment would become impaired.