Co-pilot seat is not available in the Tante Ju. Once in the gunner seat, press the key for 'AutoPilot' to get control over the gun. (Will depend on the current state of the 'Toggle Level Autopilot' control. If it's on, autopilot will switch automatically off for the gunner and on for the pilot - in single player, not in coops/df's - when you jump to the gunner seat. It switches gunnerAP back on when leaving the seat, and PilotAP back off when returning to Pilot seat. Yours appears to be off, check what key has been assigned to it, press it once and it's all automatic. But, like I said, it works differently online, when in Coops.) I'm not in the know with switching of mixture at all... the times I've flown it, to save fuel, I think I even set it as low as 60% ... even at lower altitudes. One more Ju52 tip: Taxi by only using the center engine. If you try it with all three selected, or the outer ones, it gets very weird. When running up only the 1 (left) engine, one would expect the aircraft to turn to the right. But no, it turns left. Same with right hand engine (3#), spool it up and the thing turns right.