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xkcd #3124: Grounded
(imgs.xkcd.com)
Title text:
We should have you at the gate in just under two hours--two and a half if we get pulled over.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3124/
7000 ft is relatively common for small planes like cessnas, they don't even keep pressurized cabins, but It's fine if you stay low. So there's nothing wrong with that altitude, but it's awfully low for a jet. The jet will be flying at low fuel efficiency the whole way and it certainly won't have much wiggle room if something really goes wrong. (You can lose 7000 ft of altitude very quickly)
ah, I wasn't sure because I was reading this:
https://en.m.wikipedia.org/wiki/Effects_of_high_altitude_on_humans
it seemed like between 7,000 and ~~8,000~~ 26,000 the air is not suitable, but I figured the pilot wasn't likely to be taking risks like that, so there must be some explanation
edit: mixed up feet and meters
You're mixing up feet and meters. The death zone is at 8 km, i.e. 26k ft.
2100m is barely mountaineering, you can bring grandma and the newborn hiking there and at most you'll notice a mild shortness of breath.
In fact normal cabin pressure at cruising altitude is equivalent to 7000 ft. Besides a lot of ear popping most people don't even notice it, though mild altitude sickness (i.e. a small headache) is possible, but ultimately harmless.
ah, that explains my confusion - thank you for clearing that up!