Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: 1K3 on October 06, 2005, 07:49:51 PM
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Ok i just found the command on how to variably control the RPMs separately to MANIFOLD.
what does variable control RPM do to the plane?
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btw is this the same command that gives 109s and other german planes in IL-2FB sim more artificial and unrealistic performance by manipulating the rpm control?
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If you look in E6B it will show you different rpm settings for the plane you are in. Saves on gas if you set it to max cruise. Most ppl who fly LA7's do this to conserve gas but still get to where they want to be quickly
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I do believe it controls the prop rpm
Less rpm = better gas mileage, but less thrust from the prop.
make sure you turn it back up in a fight.
I just hit wep on/off and it sets it back to max
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WWII planes had variable-pitch propellers with control systems that maintained a given RPM. So, you could control RPM and, with the throttle, manifold pressure. It's the same as, in a car, having gears, which adjust RPM, as well as a throttle.
Max power is generally high RPM and high throttle (sort of like in a car keeping max throttle but shifting as needed to optimum RPM), and max efficiency (for maximum range) would generally be lower throttle and also lower RPM (sort of like in a car having lower throttle, higher gear, and lower RPM).
As already mentioned, the E6B shows for each aircraft what RPM and manifold pressure to set for max cruise and so on.
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/just for a test grab 10k in an la7 300 mph then chop rpms..u can fly forever..la7 limited range is complete bs
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People are finally catching on.
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i believe it also feathers the prop. When trying to nurse a radiator hit Dora, shutting down engine then reducing RPMs allows for a better glide.
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Note that, with alot of early-war planes, the manifold pressure reduces when the rpm is reduced.
Aircraft with turbo-charchers (or compressors, not sure) do not do this, they can maintain MP while reducing the rpm
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Originally posted by JB42
i believe it also feathers the prop. When trying to nurse a radiator hit Dora, shutting down engine then reducing RPMs allows for a better glide.
Yes, reducing rpms to minimum prolongs glide time considerably, since prop produces less drag.
For oil hit, you can also climb to alt, shut off engine (oil loss stops), glide till your low (rpms down), restart eng to climb back up.... rinse and repeat.
Same works for radiator hits. Watch temperature carefully, just before engine dies, shut it off, glide (eng cools slowly)....
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Could the propellors on WWII-planes be turned into the wind, so they wouldn't cause any drag? (like modern prop-planes) Or did they just turn down rpm as low as possible
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Originally posted by frank3
Could the propellors on WWII-planes be turned into the wind, so they wouldn't cause any drag? (like modern prop-planes) Or did they just turn down rpm as low as possible
Id guess from the fact that they are still moving (assuming AH is modelled correctly concerning that) that they are not turned completly into the wind when reduced to min.
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Ah ofcourse! Thanks Schatzi
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Originally posted by frank3
Could the propellors on WWII-planes be turned into the wind, so they wouldn't cause any drag? (like modern prop-planes) Or did they just turn down rpm as low as possible
There aren't many singles out there with full feathering propellers. The ones that do have them are 99.99% of the time turboprops. In fact I can't think of any off hand that I've seen or flown that are piston powered with feathering propellers.
Multiengine airplanes (two or more engines) are equipped with full feathering propellers because when you lose an engine you have already lost 50% of your power. Because they are wing mounted (with very few exceptions A500, C-337) they have this lovely thing we like to call Asymmetric thrust. Because of this we lose 80% of our performance. Think about this...if you lose an engine you're down 80%! That's 20% left. Unless the airplane weighs over 6000 lbs (not typical of a light twin) or stalls at an airspeed higher than 61 kts (also not common) there is no FAA requirement for the airplane to have any single engine rate of climb for certification purposes.
The FAA requires of me that I perform a drag demo for all of my multiengine students prior to them going for a multiengine check ride (private, commercial or instructor add-on ratings). What this does is demonstrates to them the loss of performance in various configurations with an engine out.
(Keep in mind these numbers still have your good engine operating at full power!)
For instance:
Critical engine (if applicable) windmilling... -600fpm Penalty
Full Flaps........................ ............................. .. -800fpm Penalty
Gear Down......................... ............................-500fpm penalty
Add those together and that's a total of 1900 Feet/Minute in the wrong direction. If the airplane climbs at 1500 ft/minute with both engines operating then you lost an engine most light twins are doing quite well to get 250 ft/min on the remaining engine. If you left the propeller to windmill without feathering it then you're going down at 350 Ft/Minute.
That's a long ado about nothing except that the drag is modeled in the game...and if you're just now 'discovering' the propeller control then prepare for a brand new experience. In the single engine fighters if you use the - key on the numpad to pull the prop back following an engine failure or simply run out of fuel...prepare to be pleasantly surprised when you see how far you can stretch your glides.
Also take note, that the P-38 and other multiengine airplanes have full feathering propellers and this too is modeled in the game. If you shut them down in flight...they don't windmill.
Good Luck!