At 14,500 ft due to the bloods inability to carry oxygen, there is dramatic drop in oxygen saturation, which will be approximately 80% - or fully hypoxic. A person left at this altitude may experience: vertigo, nausea, weakness, increased breathing, decreased eye-hand coordination, slowed decision process and compromised vision. "You know, I think if you could package hypoxia, you could it and make a fortune. That's how good it feels. That's also how dangerous it is." (They called it Pilot Error, True Stories Begin General Aviation Accidents, by Robert L. Cohn; quote by Burt Roberts, p.113) Hypoxia is an insidious and progressive condition, and is undetectable by the pilot. You should always be aware that without supplemental oxygen at a sufficient flow, you will gradually and progressively lapse into incompetence while maintaining an absolutely euphoric faith in your own ability. A pilot's decision-making process would depend on the oxygen saturation level in his or her body. The less oxygen in one's body, the greater the chance the pilot may make the wrong decision.

According to most expert estimates, the accident rate in general aviation would drop by more than 60 percent if all aircraft were pressurized because pilots would not be hypoxic, and clear decision making would not deteriorate as a result. This would eliminate most fuel carefree attitude, most alcohol, drug and substance accidents (alcohol and drug effect are greater when oxygen level is lower); most spatial disorientation accidents (pilots would be more aware of their surroundings and would avoid becoming disoriented in the first place); most poor judgment accidents and most weather accidents. In other words, 'pilot error' accidents, which account for approximately 90 percent of all recorded accidents and incidents.