posted 04-27- 11:03 AM               

Enlighten me please.

posted 04-27- 03:28 PM               

I was puzzled because I saw in OPS that most aircraft had 4500 as the highest RPM, but they never seemed to run as high as that.

posted 04-27- 03:29 PM               

You can see this at work a little bit: take your throttle, pull it back about half way, and then slam it to max. You'll see the RPM jump up a tiny bit, then come back to what it was at. The only way to actually vary the RPM is to pull the nose way up and pull the throttle to idle. As the speed bleeds off, the prop will reach its minimum pitch trying to get back to full RPM, and once it can't decrease pitch any further, the RPM will "decay." You can also see this on landing when you slow down to taxi speed.

The manifold pressure guage is also screwed up. It is set up to read "cylinder head temp" or something like that, so it works more or less like an on/off switch with the engine.

Now, how is it REALLY supposed to work? In a piston-engined light aircraft with a "constant-speed" prop, the prop is really only constant-speed AFTER you select your desired RPM. AFAIK, this is how the fighters with constant-speed props were set up in the war. You set an RPM, and then vary your manifold pressure for power. The regulator in the prop varies the blade angle to maintain the SET RPM, not max power. If you wanted max power (speed) you'd set max RPM on the prop, and max boost on the manifold press. If you wanted best climb, that would be a combination of RPM and boost for long-duration, max climbing efficiency, and would vary from aircraft to aircraft.

Interestingly enough, while the Spit, F4U, P-51, and I think the 190 had constant-speed props, the Bf-109 had instead a "variable-pitch" prop. On this prop you set the desired pitch, and allowed the RPM to vary with airspeed and power. If you slowed down, the RPM would slow down. Speed up, and the RPM would follow. You'd have a whole slew of prop and power settings for takeoff, climb, combat, landing, cruise, etc.

The only combat sims I've seen where you can actually control the prop are CFS and Aces High.

The Corsair model was originally set up to mirror throttle position on the RPM guage and the boost guage. This is pretty much correct for the boost guage (as long as the engine is running) but not really correct for the RPM, since the guage IS set up correctly to show engine RPM, it's just that the prop and engine aren't really as adjustable as they should be. The next version of the Hog will be set up with boost guage mirroring the throttle, and RPM guage back to normal, monitoring the mostly-unchanging engine RPM. The Jug is also set up this way, and IMO that should probably be the standard as we refine the airplanes.