Originally posted by Angus
Yes, the 109's flaps were lowered by turning a wheel. I have not seen any data about it being hydraulic though, always thought it was a gearing issue. Same as the UC of the 109, and the Spitfire Mk I.
Don't know about the Mustang, it was just a lever, so it was definately not physical/geared. Rather electrical/hydraulical/pneumatic. Well, HiTech flew a P51, I am sure he can tell us!
Yep it's correct that the 109 had mechanical gearing to the flaps, operated by the pilots muscles. But you guys miss a point about flap lowering times..
From the data we see it says that full lowering would take ca25 seconds on the 109 and 15 secs on the P-51. But... that's the fully deployed flaps, for landing, 40-60 degrees, which is a LOT; we are talking here about combat flaps, which only mean small deployment, 5-10 degrees only. On the P-51 with hydraulic operation, the deployment was most likely constant speed, ie. say 4 secs (1/4 time) required to deploy combat flaps by pressing the switch. On the 109 the time is less linear, since with more flap deflection, more airflow pushing against it and the forces getting higher towards the end of the path, slowing it down - you can turn less fast the wheel with your muscles. You only put out landing flaps when landing, when the speed is not an issue.
When you lower them only a little, ie. combat flaps, the forces are less and could be applied more quickly.
That's not the whole issue however, with flap deployment you also have to change the trim of the aircraft, which could be done simultaniously on the 2-axe wheel (trim and flaps), whereas on the P-51 you first put the flaps out, and then adjusted the trim with another switch.
All in all it's not a major difference in practice imho.