canberra wrote: Back in the early eighties Boeing brought out the 757 and 767 which fly at around 40000feet. Why does the Airbus family fly lower??????
My understanding is that it will all come down to fuel consumption. Someone, something, somewhere calculates the optimum flight envelope for a given aircraft type on a given route to use minimum fuel. And that is what they will fly to if at all possible. I'm not sure getting up in the 40'000 feet plus is fuel efficient for the latest high bypass turbofans.