Thank you!
Since it seems to be rather common among operators of the DB-powered Bf 109s flying today to use the manual control of the electric propeller for various stages of flight, this morning I've been playing around with the same manual override of the prop in the sim. The switch to change between the automatic system and the manual override is just below the throttle quadrant. On the Bf 109 there is a rocker switch on the end of the throttle which, with the prop set to manual, you use your thumb to increase/decrease the prop blade angle. There is a well-known gauge on the instrument panel that looks like a clock but actually indicates the amount of degrees of prop blade pitch (every 10 minute line indicating 1-degree of blade pitch). The max setting on the gauge is the 12:30 position, indicating full fine 22-degrees, with the lowest setting being the 4:30 position, indicating full coarse 70-degrees.
On the FlyingIron model, with the prop set to manual, the prop pitch increase/decrease function is tied to the propeller axis binding. On my X52 throttle controller, I've always had the prop axis tied to the slider switch that you use with your thumb, so this works out really well. As the product manual outlines, it functions with the sim model by putting the slider in three different positions - 0-30% is decrease, 30-70% is neutral/off, and 70-100% is increase. Once you reach the setting you want, you center the axis/switch.
Among the various modern pilot reports I've read, it is usually mentioned that current operators set the prop to manual for takeoff with the prop pitch indicator set to the 12:00 or 11:30 position (to ease the amount of torque/p-factor on takeoff). Dave Southwood, in his pilot report about flying the Bf 109G-2 "Black 6", mentions that for aerobatic display flying they would use 1.15 ata (max-continuous power) and would put the prop control to manual and set it for 2400-2500 RPM, so as to avoid overboosting the engine. According to Southwood, this would mean setting the prop to the 11:05 position at high speeds, such as prior to entering vertical maneuvers, but it would have to be increased to the 11:20 position over the top of a loop. This resulted in a lot of head-in-cockpit time and having to make propeller adjustments throughout an aerobatic display, greatly increasing the pilot's workload. Again, during the landing approach, I've read that the prop is commonly set to the 11:30 position, in-case of go-around. In cruise flight the manual control can come in handy too as you can lower the RPM farther than the automatic system will, which will save you a bit on gas (for instance, in automatic, standard cruise is 1.05 ata / 2100 RPM, but in manual you can fly with a more economical setting of 1 ata and 1800-2000 RPM).
Last year at Oshkosh, Bruce Winter and Mike Vadeboncouer mentioned that, with Bruce Winter's extremely accurate Bf 109G-6, they hadn't quite gotten the automatic prop control working properly yet, with some more tweaking still having to be done at the time, so the prop/RPM was always being controlled/adjusted manually. Because the engines are so rare and expensive to overhaul, it was mentioned that they were using reduced power settings across the board (probably matching up with what other operators have stated, such as using only 1.1 ata on takeoff).
