In the preamble to the final Respiratory Protection Standard, OSHA discussed extensively its rationale for requiring that employees breathe air consisting of at least 19.5 percent oxygen. The following excerpt, taken from the preamble, explains the basis for this requirement: Human beings must breathe oxygen . . . to survive, and begin to suffer adverse health effects when the oxygen level of their breathing air drops below [19.5 percent oxygen].
- The Tu-144 supersonic transport was the fastest commercial jet plane at Mach 2.35 (1,555 mph, 2,503 km/h). It went into service in 1975, but soon stopped flying. The Mach 2 Concorde aircraft entered service in 1976 and flew for 27 years..
Long considered the fastest passenger plane, the Boeing 747 has several variants, each with slightly different speeds. The fastest of them are the 747-400, 747-400ER and 747-8L, all of which can cruise at Mach 0.855ish, and have top speeds of Mach 0.92. So close! Then we look at Airbus.