Sorry Flyboyj,I meant I couldn't see why he'd need to crank it through its entire range,all 5 and 3/4 turns,in normal flight conditions.12 degrees would be an enormous change in trim!
That trim wheel lies right next to the flap wheel and allied test pilots flying the Bf109 liked the ability to turn the two together hence simultaneously compensating for changes in trim as the flaps were lowered or raised. Still had to take their left hand of the throttle to do it though.
Cheers
Steve
Sorry Flyboyj,I meant I couldn't see why he'd need to crank it through its entire range,all 5 and 3/4 turns,in normal flight conditions.12 degrees would be an enormous change in trim!
That trim wheel lies right next to the flap wheel and allied test pilots flying the Bf109 liked the ability to turn the two together hence simultaneously compensating for changes in trim as the flaps were lowered or raised. Still had to take their left hand of the throttle to do it though.
Cheers
Steve
The biggest trim changes in the planes I have flown, occur when dropping the flaps, especially the final or greatest setting. I think that is why the trim wheel was designed as such on the 109. Also realize that aircraft designers usually give you just enough to get done what the design specs called for. Willy "giving" the amount of trim that he (or his designers did) was to cover the expected trim problems to be encountered. The centerline tank, bomb or bombs, trapped fuel, flaps / slats fail to operate, battle damage, all will induce abnormal trim settings compared to usual.
As for taking your hand off the throttle while trimming the horizontal tail, that's not a big deal. On take off the power is set and will most likely be unmoved until in the clean configuration and at climb speed. During approach, you most likely are not flying close formation (requiring lots of little power changes), so can again set the power, and as the speed bleeds off adjust your configuration and trim.
Having never ridden in or flown a WW2 combat aircraft, the above is just a guess on my part.
As for taking your hand off the throttle while trimming the horizontal tail, that's not a big deal. On take off the power is set and will most likely be unmoved until in the clean configuration and at climb speed. During approach, you most likely are not flying close formation (requiring lots of little power changes), so can again set the power, and as the speed bleeds off adjust your configuration and trim.
Standard procedure for everything I've flown has been:
Airborne - gear up, set climb power, then trim for the climb
Approach - downwind, set approach power, trim, gear down, flaps down (order depends on speeds), re-trim. If you get it right, you can get away with not touching the power again until short finals, when pushing the prop to full RPM (full fine). Depending on the aircraft and approach, I may or may not re-trim at this time.
The trim is largely to reduce pilot fatigue, so an approach and landing can be done without it (as long as it's somewhere near right).