Drifting off course (thread). In terms of flight time the Qantas Catalina WWII flights from Koggala Lake (Sri Lanka) to Perth, Australia would count as the longest. An average of 28 hours for the trip, the longest being 32 hours 9 minutes. The fact you couldn't rock up and buy a ticket puts it out of the commercial category though. Payload three pax and 69 Kg of mail, no single engine performance (except down) for the first ten hours (never had a failure - love P & W?), and no crew relief.
Us youngsters got it easy or what?