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CapnOz

How to use Feathering

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This subject doesnt seem to be covered well.Could some one please explain " feathering" ?When how where ..all that good sttuffThanks

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I will try to answer a complex question with a short answer. The variable pitch on a propellor can rotate the blades of the prop to get the best performance. On takeoff and landing you will have the props full forward. As you take off you will adjust the manifold pressure/torque to a set amount depending on the aircraft and adjust the props to a specific RPM. The same goes for cruise. These will normally be in the POH. In the Seminole I got my rating on it was also located on the sun visor. The propellors are "feathered" when you have an engine failure or when you need to shut down an engine. The drag created by a windmilling engine is enormous and by feathering the blades so the are straight into the wind they will cease spinning. Some aircraft will autofeather when the props decrease below a certain RPM. This would normally be in turboprops. Light reciprocating twins will not do this because they are unable to come out of feather when the aircraft is restarted. In fact after an engine is shut down in a light twin in the feathered position the only way to take them out is to use a tool called a spreader and the maintenance engineer has to manually rotate the prop. I hope this has helped you understand a little about the variable pitched propellor and feather.Richard Rowe

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Hi Peter,I'm not exactly sure what you mean, but if you're asking what feathering is in general, it's when, in the instance of an engine failure or the like, the propeller blades are turned so they are parallel with the flow of the air.For instance, say if the normal blade angle is like this: , feathering would have the blade like so |In flight simulator you either move the prop speed all the way down to "feather" and or hit CTRL+F2 until it is feathered.

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Hi Andreas,No you cannot see them move. It's explained in the manual that the blade angle is controlled by engine oil pressure and therefore, when the engine is off, the blades cannot be controlled, so they opted to have them always look feathered when off.

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Hi, as imoore explained Andreas, the PT6 turbine which the Beech 1900 is equiped with and so is the king air, are called "free" turbine, they use differential air pressure from the turbine to spin the props, and when the engines are not running, they are always in the "feather" position. Other kind of turbines such as the geared ones (Garret TPE series) dont feather when they arent running, and the operation is rather different and more delicate. I hope this little information was of some help of you. Greetings

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>...I hope this little information>was of some help of you. GreetingsYes! Thank you both for the explanation!-Andreas

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