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aeolus

Odd engine RPM Behavior

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I'm no longer getting full engine RPM on take off in just about all of my non constant prop RPM single engine aircraft (default c172, DF ArcherIII, etc...). I am using the default flight at KSEA, so altitude is not a problem. I'm using a old tried and true CH Yoke of which I have checked the calibration. This problem hasen't occured in any other type of aircraft in the sim. I am at a loss as to what would cause this. Anyone have a clue?Thanks, -R.

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Not on all aircraft? Anyway, be sure controls sensitivities sliders for joystick (CH yoke) throttle axis is full right for sensitivity and full left for null zone.

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>Not on all aircraft? Anyway, be sure controls sensitivities>sliders for joystick (CH yoke) throttle axis is full right for>sensitivity and full left for null zone.Thanks. I've checked the axis's for Throttle, prop, and mixture within the sim and through FSUIPC (I use this for calibrating the yoke) and there all fine. I've also deleted and had the sim rebuild the FS9.cfg file, -no joy! I've noticed that on constant speed prop aircraft, on take off, I can reach full MP no problem, but the last quarter of max prop RPM is acheived slowly, bearly in time to meet rotation speed. What ever this problem is, it seems to be effecting all of my aircraft. :-(

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>I've noticed that on constant speed prop aircraft, on take>off, I can reach full MP no problem, but the last quarter of>max prop RPM is acheived slowly, bearly in time to meet>rotation speed. What ever this problem is, it seems to be>effecting all of my aircraft. :-(I never performed a takeoff with a real life airplane and fixed pitch prop at sea-level, but I can tell you that a fixed pitch prop and engine capable of 2700 rpm will only achieve around 2300 at our 4600' msl. airport on the takeoff roll.A fixed pitch prop is usually a compromise between takeoff/climb thrust & cruise settings. A C/S prop's governor can be set to achieve much higher rpms on takeoff, using fine pitch, and they will increase as you've mentioned. Generally, the full redline RPM will never be reached during a static (non-moving) runup. These props are adjusted for full RPM (redline) while at level flight, and prop control pushed full forward.L.Adamson

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>I never performed a takeoff with a real life airplane and>fixed pitch prop at sea-level, but I can tell you that a fixed>pitch prop and engine capable of 2700 rpm will only achieve>around 2300 at our 4600' msl. airport on the takeoff roll.>>A fixed pitch prop is usually a compromise between>takeoff/climb thrust & cruise settings. A C/S prop's governor>can be set to achieve much higher rpms on takeoff, using fine>pitch, and they will increase as you've mentioned. >>Generally, the full redline RPM will never be reached during a>static (non-moving) runup. These props are adjusted for full>RPM (redline) while at level flight, and prop control pushed>full forward.>>L.AdamsonThanks for your response and what you have said makes perfect sense.I'm beginning to doubt my memory on what I used to get in the sim, but if you were to load up the default c172 (or the RealAir c172) at KSEA, give it full throttle, and on the take off roll, would you achieve around 2600 RPM (red line)? At best I'm only able to get around 2200 to 2300 RPM, and I might get 2400rpm by the time I get to 2000 feet. Is this normal for the sim?

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L.Adamson is correct. An engine with a fixed pitch prop will not reach redline at full throttle when the plane is stationary (Cessna 172). A constant speed prop changes pitch to maintain a selected rpm (Cessna 182). Your simulator is working correctly.

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Thanks, guys! This gives me great peace of mind and has been very informative at the same time.:)Regards, -Robert.

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