With a starting altitude of 11,505 feet, it not only provides an easy entree to Aspen's highest terrain, it also affords the chance to speed acclimatization to the thin air by following the mountaineering adage to "climb high, sleep low".
However, for the present case, the starting altitude of the daytime irregularity structure is near/above the F-region peak (~ 360 km) where the background plasma density gradient is usually not favorable for plasma instability.
They start at altitudes of 4,300 to 4,600 feet, and in the northeast they ascend to 6,200 to 6,600 feet.
Last January, for instance, China's aviation authorities allowed a few private helicopters to start low-altitude flights over Hainan, the southeastern island that is a popular tourist destination.
It was here, 8,000ft above sea level, that Britain's double Olympic and world champion Farah started comprehensive altitude training in 2010 and it is here Britain's finest distance runners test their stamina and souls.
In quick succession the B-17 lost two more engines and started losing altitude very rapidly.
Three of the Olympic contests start at higher altitude, where the conditions are fine, but their courses finish at the base of the mountain where the other three contests take place.
In October, on the twentieth anniversary of Erowid's launch, I travelled to the home of its founders, in the Gold Country of northeast California, where the Central Valley gives way to the Sierra Nevada and road signs along I-80 start marking the altitude.
"I think, generally, we've come out of the dive and we're starting to gain altitude," Powell told CBS This Morning, adding that "housing is now starting to pick up" and "consumer confidence is rising".
