> If there's a manual up there, then maybe that will have info?
Many (most?) airlines have abandoned printed manuals and paperwork in cockpits and have switched to tablets - often iPads - for weight considerations and because they are easier to just keep updated, and those are usually non-accessible to random passengers. Notable exception are emergency checklists.
All planes are required to have the original POH onboard. However those don't really tell you how to fly the plane it's more focused on things like Vspeeds minimum flap extension speeds etc..
That varies based on the certification rules. My older 182 only had to have the operating limitations and weight and balance info (“O+W” in ARROW), but they did not have to be original.
My later year A36, I believe needs the original AFM/POH. (In any case, I do carry it.)
If you didn’t know how to fly, you couldn’t read enough of the book to figure it out before the aircraft departed controlled flight (if not on at least a wing-leveler autopilot).
As noted, on an airplane without an AFM (Approved Flight Manual) the POH does not need no be on-board, only a placard with the operating limitations. The cutoff for the AFM requirement are individual aircraft that had their first flight after 1 March 1979.
As the owner/operator of an early 1979 build aircraft that does not have an AFM, I’ve had this discussion with maintenance/airworthiness inspectors so frequently that I keep a printout of 14 cfr 21.5 in my POH.
I'm also an owner of an older 182 (1966 - 182K) I agree with you the POH won't really teach someone enough about the aircraft to fly it let alone operate the radios.
Many (most?) airlines have abandoned printed manuals and paperwork in cockpits and have switched to tablets - often iPads - for weight considerations and because they are easier to just keep updated, and those are usually non-accessible to random passengers. Notable exception are emergency checklists.