Talking of long endurance flights, Guinness say that the longest ever (excluding space flight) was airborne for just under 65 days, from Dec 58 until Feb 59. It was a Cessna 172 with 2 on board, with long range tanks that allowed it to fly for about 24 hours between refuelling, which was done by flying at 20 ft above a fuel tanker and picking up a hose. Only saw a brief entry about it on the internet, so I don’t know how they managed for food etc, presumably that was also picked up in flight from a chase vehicle.