@whitequark arguably a far better metric for the denominator in that calculation would be the number of bags you took. mean passenger mass probably doesn't vary that much for any given route, whereas bag count is probably a fairly accurate proxy for 15-20 kg of carried mass each.

@whitequark although even then the calculation has major uncertainty factors for reasons you don't even control as a passenger, like "did the flight sell out?" (since you're then dividing the constant mass of the aircraft by fewer passenger)

@chrisvest @gsuberland for a B737-600, the empty jet weighs 36t and the passengers would weigh ~13t if i go with the "dense but still realistic" seating. so it's not an order of magnitude

edit: fixed typo (767->737)

@whitequark @chrisvest and even just from passive consumption of ACARS Drama it seems clear that aircraft are fuelled to significantly different levels depending on the passenger load.

(although I did also know this from other sources)

@whitequark @gsuberland I looked at the 787 on wikipedia and its in a 200t-250t weight class, with the 787-10 carrying up to 310 passengers. I picked 85kg per passenger+luggage ( maybe that’s low) which gave me 26.3t

@whitequark @gsuberland I think your numbers are off, though I can’t find the 767-600 specifically. A 767-300 has max take-off weight of 158t and max payload of 40t. I can’t imagine the fuel makes up the difference.

@chrisvest @gsuberland source

@chrisvest @gsuberland oh, sorry, i made a typo. it's 737, not 767

@whitequark @gsuberland ooh, yes, tracks. Seems like, the smaller the plane, the bigger a percentage of the take-off weight the passengers can take.

@chrisvest @gsuberland that is an even stronger argument against making a single pair of figures for economy/business: it strongly depends on the composition of the fleet!

@gsuberland @chrisvest meatbags: fuckin heavy, actually

@gsuberland @chrisvest i was curious and did some calculations, apparently if you go with some reasonable assumptions (158 cm max linear dimension for checked bags, 30 kg max weight) then the checked bag density must be no more than 1/5 of passenger density

@whitequark @chrisvest related: a lot of lift weight capacities are actually pretty terrifying when you do the numbers. very easy to overload a lot of them with just a few tall heavily built people. and the safety margins on a lot of them are... uh... degraded.

@gsuberland @chrisvest huh. well, that's one more thing i'll proceed to not think about

@whitequark @chrisvest the good news is that there are like 4 redundant safety mechanisms to prevent plummets, and a couple of them are effective far beyond the stated weight capacity, even with worst-case dynamic loads. but the experience of stepping into an aging lift that barely had the capacity for two people when first installed, and feeling it drop a full 6 inches, is deeply alarming.