@whitequark it *should* be about the weight rather than the volume because thrust overcomes drag, and induced drag originates from the lift vector being in slightly the wrong direction, which must counteract the total wet and dry mass of the plane
this was also the rationale given for trying to overcharge overweight passengers. it was a more woke time though, so as far as i remember those kinds of surcharges fell out of favor (?)
@estelle yeah i don't think anybody tried it since, and even at the time it was probably a publicity stunt? wasn't it done by ryanair
@whitequark i had to look it up, it appears to have been started by samoa airlines in around 2013 (has it been that long?), and cnn circa 2023 says united airlines and others require buying two seats, but may refund it if empty seats are available
fox news (ugh) outright states in their article that "1% reduction in weight would save 0.75% the fuel consumption"
canada appears to have a "one person, one fare" law for airliners
(i have not flown in an airliner for a very long time)
