Originally Posted by
artee
This bear of little brain does not understand. Surely if the 777 has a max cabin alt of 8,000 ft, and the 787 has a max cabin alt of 6,000 ft, even if the 777 "cruises significantly lower", cruise alt will be significantly higher than 8,000 ft, so that the cabin pressure will be 8,000, vs the 787 at 6,000. What have I missed?
The "8000 feet cabin altitude" figure is a maximum number on most planes, if they're cruising below the max altitude then your actual cabin altitude can and will be lower than 8000 feet. It’s dependent on max PSID (differential pressure between outside and inside). So the lower you fly, the lower the cabin can be.