Squawk Codes Explained: 1200, 7000, 7400 and 7777

Squawk Codes Explained: 1200, 7000, 7400 and 7777

Type “what does squawk 7700 mean” into a search box and you get a correct answer in five seconds. Type “what does squawk 2303 mean” and you get a page of confident nonsense. That asymmetry is the most interesting thing about transponder codes....
FAR 91.211: How Long Can You Fly Without Oxygen?

FAR 91.211: How Long Can You Fly Without Oxygen?

Ask how long a pilot can fly without oxygen and you get two answers that do not resemble each other. The legal answer lives in 14 CFR 91.211, and at 12,000 feet it is remarkably relaxed: fly all day. The physiological answer comes from the FAA’s own aeromedical...