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Turboprop-handling

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Guest janpfs

Hello.Hope there are some "turboprop-fans", who can help me here:I would like to know more about "Prop Sync" and "Autofeather". Sure the names say what they`ll do, but I would like to understand more about "when to use, and why"??I`m sure someone can explaine me this better than what I can read inside FS?Regards, JP

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>I would like to know more about "Prop Sync" and "Autofeather".>Sure the names say what they`ll do, but I would like to>understand more about "when to use, and why"??>>I`m sure someone can explaine me this better than what I can>read inside FS?>>Regards, JPThe autofeather feature, when armed, automatically feathers (i.e. puts blades pitch at about 90 degrees) the prop of the failed engine. This way, minimizes prop drag and therefore decreases yawing moment and total drag due to windmilling prop. A feathered prop stops windmilling.The Prop Sync syncs the spinning of the 2 props, this way the discomforting rrrrRRRRrrrrrRRRRRR sound is removed.Marco


"The problem with quotes on the Internet is that it is hard to verify their authenticity." [Abraham Lincoln]

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Guest allcott

Generally, prop sync is OFF for takeoff and landing, ON in climb, cruise and descent. Gives the passengers an easier time.Autofeather will be ON for takeoff and landing and OFF for climb, cruise and descent. Gives the pilot an easier time when workload is highest.I don't think asynchronous props are modelled in FS. Least, I've never found an aircaft where it makes the slightest difference to noise.Allcott

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Guest Peter Sidoli

>I don't think asynchronous props are modelled in FS. Least, I've never found an aircaft where it makes the slightest difference to noise.Allcott

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Guest janpfs

Thanks to you all.That was just what I needed to know!:-)I totally agree with you, about the sounds in FS. But maybe payware models have these options? I also miss a larger turboprop with a prop-brake system. Just love to see a plane with one engine started, but no propellers spinning.But I guess I can have this with payware-models too. By the way, what payware turboprops would any of you recommend? Anyone better than others? I have thougth about the Flight1 ATR, as one of the better models.Happy flying, JP

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>But maybe payware models have these options? I also miss a>larger turboprop with a prop-brake system. Just love to see a>plane with one engine started, but no propellers spinning.Well then get the Flight1 ATR.

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Guest enave

>I would like to know more about "Prop Sync" and "Autofeather".>Sure the names say what they`ll do, but I would like to>understand more about "when to use, and why"??Hi. I would just add the following to what other people have said: There is a principle of physics, I forget the name, but it states that a free-spinning propeller generates as much resistance (that is, drag) as a solid disc of the same diameter. That's a lot of drag! Imagine mounting a four foot diameter solid disc out on one of your wings. You'd never get the plane off the ground, and even if you did, you'd have to keep one foot on the rudder to keep from going into a flat spin.It is this principle of physics that makes auto-gryos work.So anyway, if you are coming in for a landing and you lose an engine, you need to turn the blades into the wind (that's called feathering them) and you need to do it really fast. This is in addition to all the other things you have to do, like making sure the engine isn't on fire, compensating for the reduced power, and generally taking extra care not to become a dirt dart.Auto-feather reduces your workload in an emergency. It's just one less thing you have to think about.

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Ditto to the previous posters. The only reason to have the prop sync in fs is to have the button there. When you are selecting engine RPM via the keyboard, the engine parameters are identical. It's not always so IRL. And, like everyone else said, you sync the props for the sake of your ears, usually not until the plane is cleaned up and you don't have any very pressing navigation issues to attend to first. The autofeather is a great workload saver on takeoff when workload is extreme. It is also a safety bonus because it helps eliminate the possibility of feathering the wrong engine. The autofeather is there to handle the preliminary workload for us if the engine fails during t/o, just long enough for us to establish best single engine rate of climb, contact the tower, and then we secure the engine.The autofeather isn't as useful unless you have failures programmed into fs, which you should try some time. :-)

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The autofeather system is armed prior to every takeoff. Its purpose is to detect a failing engine and minimize its propeller drag. Should the system sense a drop in torque

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Guest

Since the question seems to have been answered, I was wondering about something else. How do I use the cowl flaps? I noticed them in a few aircraft I have purchased, the Carenado 182, Dreamfleet A36, etc

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Guest allcott

High power settings + low IAS = HOT engine = open cowl flapsThe cowl flaps are just an optional cooling door, to be used when you need it because airflow over the cooling fins is low. Hot ambient temperatures are another time when extra cooling may be required. Generally, unless the ambient is cool or the manual says otherwise, always use cowl flaps for full power takeoff and climbs.Allcott

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Guest

Thanks for the info, how much drag do these flaps produce?

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Negligible. In the 182 I fly, you'll lose maybe 3 or 4 knots when the flaps are open.


John Howell

Air Traffic Controller - Houston, TX

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Guest Ozark Dogfighter

I may be completely wrong here, but it's not life or death and I like this discussion..I believe I read somewhere that the DC3 has some issues with the cowl flaps interrupting airlow over the control surfaces. It's negligable I'm sure, but in certain conditions could be dangerous. Also, there is some talk amongst the older fellers that leaving the cowl flaps closed at start-up can actually make engine warm-up faster. I've heard the arguments against that too, namely creating too much heat in the cowling and frying the ignition wiring. I imagine those engine harnesses are NOT cheap for a Wright radial. Don't forget to keep 'em closed while parked over time so the birdies won't build nests in them! And always check 'em with a can of Raid before start-up. Pesky wasps and hornets!http://home.earthlink.net/~dawgfighter/sit...es/swvasig1.gif-Jeremy BurchSWVA4806 http://www.virtualswa.com/home.phpThe Ozark Dogfighter http://forums.avsim.net/images/wedge.gifHappy Flying!

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I do know that in twins, they say to drop the cowl flap on the working engine and raise the flap on the dead engine to help yaw the aircraft a little, and cool the working engine that is now having to operate at a higher power.----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach


John Morgan

 

"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach

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