19.06.2008, 02:15
I'm pretty sure I've figured out all the propellers lately.
The De Havilland prop is a three speed variable pitch type, where many contemporaries are two speed variable pitch types and earlier ones were fixed pitch. In il2 these transitional propeller types are modelled as simply a variable pitch requiring constant manual pilot adjustment. An example would be the Hurricane Mark I (modelled with a Finnish made variable pitch type, probably a two-speed historically as most were, that is Cruise/Climb and Take-off/combat settings historically but in the sim there is the full range of pitch available by manual pilot selection). Another example would be the Ki-43-I which I know was fitted with a two-speed variable pitch type historically (so were many Ki-27).
The Rotol Constant Speed propeller is a totally different kettle of fish historically, but it is not so much different in Il2 modelling. You have the full range of pitch available by pilot selection, but constant adjustment is not required because the pitch control limits engine speed. But there is one difference in types of Constant Speed propellers: the electric (Rotol, Curtiss) and the hydraulic (used in MiGs and Tempests for example). With hydraulic or "hydromatic" constant speed types there is a slight lag before the propeller gearing limits engine speed, so you need to throttle back a little in dives for those aircraft types and apply power gradually coming out of dives to avoid engine damage. I believe the hydraulic system is more robust however.
The German aeromechanical screw is different again, because it uses weights and mechanics to optimise propeller pitch for engine speed settings using the throttle alone. It is a far more advanced system and was adopted by most well budgeted civilian manufacturers post war. The Piper I learned to fly in for example had an aeromechanical screw just like a 1941 Messerschmitt and had great power efficiency from it (performing much as a model with a 30% more powerful engine without one).
Just to recap, in il2 modelling, the fitment of a De Havilland variable pitch propeller would be the same as fitting the Hurricane Mark I FM for propeller pitch, or the Ki-43. It would be pretty much the same as the existing Rotol but would no longer adjust or limit engine speed without manual pilot adjustment. To get a truly historical feel you would need a new propeller pitch modelling in a new FM containing only two or three selectable propeller pitches for those models which had variable pitch and not Constant Speed types. It is a bit of a fault in the sim. Unfortunately this would require FM modification for a wide variety of early war aircraft, and FM modification is not done here or even discussed. I'm not discussing it by the way, simply mentioning the site rule.
At any rate since the De Havilland was introduced in 1938 and the Rotol by 1940 relatively few Mark I Spits probably used it anyway, especially by September '40. You'd probably want the De Havilland more for the Hurricane, even then only for overseas service or exports, and the Mark I already has it. Well, Il2's version of it.
The De Havilland prop is a three speed variable pitch type, where many contemporaries are two speed variable pitch types and earlier ones were fixed pitch. In il2 these transitional propeller types are modelled as simply a variable pitch requiring constant manual pilot adjustment. An example would be the Hurricane Mark I (modelled with a Finnish made variable pitch type, probably a two-speed historically as most were, that is Cruise/Climb and Take-off/combat settings historically but in the sim there is the full range of pitch available by manual pilot selection). Another example would be the Ki-43-I which I know was fitted with a two-speed variable pitch type historically (so were many Ki-27).
The Rotol Constant Speed propeller is a totally different kettle of fish historically, but it is not so much different in Il2 modelling. You have the full range of pitch available by pilot selection, but constant adjustment is not required because the pitch control limits engine speed. But there is one difference in types of Constant Speed propellers: the electric (Rotol, Curtiss) and the hydraulic (used in MiGs and Tempests for example). With hydraulic or "hydromatic" constant speed types there is a slight lag before the propeller gearing limits engine speed, so you need to throttle back a little in dives for those aircraft types and apply power gradually coming out of dives to avoid engine damage. I believe the hydraulic system is more robust however.
The German aeromechanical screw is different again, because it uses weights and mechanics to optimise propeller pitch for engine speed settings using the throttle alone. It is a far more advanced system and was adopted by most well budgeted civilian manufacturers post war. The Piper I learned to fly in for example had an aeromechanical screw just like a 1941 Messerschmitt and had great power efficiency from it (performing much as a model with a 30% more powerful engine without one).
Just to recap, in il2 modelling, the fitment of a De Havilland variable pitch propeller would be the same as fitting the Hurricane Mark I FM for propeller pitch, or the Ki-43. It would be pretty much the same as the existing Rotol but would no longer adjust or limit engine speed without manual pilot adjustment. To get a truly historical feel you would need a new propeller pitch modelling in a new FM containing only two or three selectable propeller pitches for those models which had variable pitch and not Constant Speed types. It is a bit of a fault in the sim. Unfortunately this would require FM modification for a wide variety of early war aircraft, and FM modification is not done here or even discussed. I'm not discussing it by the way, simply mentioning the site rule.
At any rate since the De Havilland was introduced in 1938 and the Rotol by 1940 relatively few Mark I Spits probably used it anyway, especially by September '40. You'd probably want the De Havilland more for the Hurricane, even then only for overseas service or exports, and the Mark I already has it. Well, Il2's version of it.