Tigger said
Between 10,000 and 15,000 ft the ability to perform skilled tasks such as aircraft control and navigation are impaired
I've been at 14K feet on Mount Rainier. The above description is accurate, especially when happening almost instantaneously. While climbing from 10,000 feet for 6 to 8 hours allows one to sort of acclimate- most first timers( like myself years ago ) start to have a hard time doing all but the most simple tasks-or concentrating. While one would think you would be gasping for breath above 12K or so, you do NOT notice that effect other than the exertion issue which **seems** to be moderate. IMHO- those who think they can remember a multi step procedure under more severe cases ( above 25 to 30 K feet for example ) are simply kidding themselves. Any such response will probably be from " memory' - muscle memory- or similar. Which requires practice, practice, practice. I'm sure a condensation ( moisture smoke) filled cockpit does not help ..