Or look at the plate in the L1 door frame as you enter the aircraft. (for many airliners: https://www.airliners.net/forum/viewtopic.php?t=755373 https://www.ai

Or look at the plate in the L1 door frame as you enter the aircraft. (for many airliners: https://www.airliners.net/forum/viewtopic.php?t=755373 https://www.airliners.net/forum/viewtopic.php?t=755373 )