[1] There's two metrics airlines report: Cost per Available Seat Mile and Passenger Revenue per Available Seat Mile.
This is the cost/revenue for flying a seat, which may or may not be occupied by a person, to a destination. If the seat is empty it gets $0 in revenue but still costs money.
You can calculate the profit made from selling tickets per seat mile by PRASM - CASM.
United is the closest, with only a 0.04¢ loss on every seat mile.[1] the other airlines lose 1-2¢/mile.
The jets are a loss leader for credit cards.
https://finance.yahoo.com/news/big-airlines-lost-money-flyin...
[1] There's two metrics airlines report: Cost per Available Seat Mile and Passenger Revenue per Available Seat Mile.
This is the cost/revenue for flying a seat, which may or may not be occupied by a person, to a destination. If the seat is empty it gets $0 in revenue but still costs money.
You can calculate the profit made from selling tickets per seat mile by PRASM - CASM.