Passengers with severe allergies?

[MARC Rider]

Another thing of relevance to transcontinental travelers is that nearly all commercial airplane cabins are pressurized to the equivalent of an altitude of 8,000 feet. I even checked this once, taking an altimeter aboard and getting a readout of about 8,000 feet when the pilot told us we were at 35,000 feet. So unless you can get a ride on a ship passing through the Panama Canal or around the Horn, you will have to deal with an altitude of at least 5,000 feet or its equivalent if you want to travel from the east coast to the west coast of North America.

Actually, if you want to take a roundabout route through Canada, one can go via Edmonton and Yellowhead Pass topping out at 3,700 ft.

 

[jis]

Actually, if you want to take a roundabout route through Canada, one can go via Edmonton and Yellowhead Pass topping out at 3,700 ft.

If you can find an A350 or 787 flight you could get cabin pressure altitude of 5,500-6,000 feet and incidentally higher humidity too. It actually does feel different if you are sensitive to such things. A380s also fall in the same category but not too many of those provide cross continent flights in the US.