For a number of reasons, airlines obviously must keep detailed archives about every individual aircraft they operate.
~How detailed are such records? Presumably all maintenance info is kept, but how about other things, such as flight numbers, e/r info, pax loads, delays, incidents, squawks, etc?
~How long is the information kept? I imagine these days it could be kept forever, but what about records from pre-computer times?
~Does the level of detail vary by airline, or is it a matter of official regulation?
~Is it possible to trace which particular aircraft/tail number operated a particular service on a particular date? How?
For a writing project I'm about to start I will probably find myself needing to find records of first/last services to particular destinations; but I'm intrigued by the subject generally. All help gratefully received!