Doug Huffman wrote:
Please do not give such nonsense currency.
The chances of a significant bullet strike from the inside is lower than in air combat and is easily calculated and vanishingly low. It is on the net, YMMV.
Pressure control in a turbo-whatever airliner is by bypass-air at a relatively constant pressure. Cabin pressure is regulated by a variable orifice in exiting air, that may be a foot in diameter. There is sufficient flow to maintain pressure through many bullet holes.
Believe nothing you read or hear without verifying it yourself unless it fits your pre-existing world view. The conspiracy of ignorance masquerades as common sense.
A foot in diameter is also somewhat misleading. I suspect that the orfice is fully open at Sea Level to prevent pressurizing the cabin well above sea level.
At altitude, you would probably have that orfice regulated down to a much smaller size.
The airlines care nothing about the effects on an airliner from a bullet hole. All they care about is fuel efficiency and meeting air replacement regulations.
Pressurized air is very expensive in fuel usage. So, if the inlet is a fixed size, which actually does make sense, then it would probably be sized to provide enough air for the minimum number of air exchanges needed for that airline, with a little extra margin.
I seem to remember a mid size jet, about 10-15 years ago had an accident where 8 feet of the top of the fusealage ripped off at about 20,000 to 30,000 feet. Passengers seated under that area could look straight up and see open sky. Basically the jet turned into a convertable. Memory is fuzzy but I think it was about 100 passengers onboard. No deaths. Although a lot soiled underware.
