Often this is indeed trust-based, but the trust isn't due to you having a card issued by a trusted bank (most airlines accept debit cards too), but rather due to passengers being extremely visible and well-identified:
In-flight credit card fraud is an incredibly bad idea, given that most countries check your ID at least at some point during getting on the plane, and seats are usually assigned as well. (Doesn't mean that nobody tries, of course [1]).
Sometimes airlines also use ACARS (basically airline-specific telex over VHF, HF, or satellite) to send the card number to their backoffice for authorizations of large amounts, such as business class upgrades.
These days, of course, Internet connectivity is getting more common, and with that the problem will likely go away.
Not that I disagree, but it does make me wonder if this would be one rare instance where American Express which I know is notorious for siding with their customers (at least for a time? - my father worked as an accounts payable accountant at a big hotel in Orlando near Disney World and he said American Express was notorious at not paying even with signature if their customer claimed it was fraud) would still side with their customers. Leaves one to wonder if they even take Amex on flights.
I still remember them taking my card which I think was a debit card on a flight and shoving it into carbon copy paper and basically billing me whenever we landed. This was late 2000s. From Puerto Rico to Florida.
I doubt you'll see any bank not siding with the cardholder in an offline or deferred-online scenario, since they're usually not liable for any ensuing fraud and accordingly can just charge the transaction back from the merchant.
In-flight credit card fraud is an incredibly bad idea, given that most countries check your ID at least at some point during getting on the plane, and seats are usually assigned as well. (Doesn't mean that nobody tries, of course [1]).
Sometimes airlines also use ACARS (basically airline-specific telex over VHF, HF, or satellite) to send the card number to their backoffice for authorizations of large amounts, such as business class upgrades.
These days, of course, Internet connectivity is getting more common, and with that the problem will likely go away.
[1] https://www.sunderlandecho.com/news/pair-spared-jail-after-a...