prop feather?

[jlab58]

i flew the DC3 today and i notice these prop feather levers that i never used. what are they for? thanks.

[expat]

Feathering a propeller is used (mainly) when you have an inflight engine shut down, though many modern aircraft with props will auto feather at shut down in the air and on the ground. The propeller blades are then turned edge on to the on coming airflow. This is done for a couple of reasons. If a propeller windmills in flight, then the engine or gearbox will still be turning, and after all for what ever reason you have just stopped your engine. You may then have lubrication problems and  over heat and fire. A second important reason, is drag. A wind-milling propeller will cause a negative thrust. Someone else could maybe explain it better, but the one thing to know about propellers is, you could study the dam things for 20 years and still have no idea about them

Matt

[jlab58]

so, it's use to stop an unwanted action of the wind on a non fonctionning prop. that's clear... does that mean if i park my plane outside that i should use it to protect the prop.

[expat]

so, it's use to stop an unwanted action of the wind on a non fonctionning prop. that's clear... does that mean if i park my plane outside that i should use it to protect the prop.

No, if the wind is strong enough to turn the prop, then you have greater problems.....like finding your aircraft in the next field Saying that, as a rule turbo props will feather automatically on shut down on the ground. You need to ask further about piston aircraft, I have not worked on them.

Matt

[garryrussell]

The older turbo props don't auto feather on shutdown.

There are more that don't then those that do

[Fozzer]

For anyone using Aircraft fitted with Variable pitch, Constant speed, Feathering propellers, etc, this makes essential reading...>>>

http://www.thaitechnics.com/propeller/prop_control.html

The system is used on some piston engines, but more often on Turbo-prop, turbine engines (P&W PT6 etc).

Independent Propeller and Throttle Controls are often used.
Improper use of the Propeller controls can seriously damage an engine.
A careful study of the Aircraft Owners Handbook is highly recommended BEFORE using Aircraft fitted with this system of Propeller control.

It also makes interesting/educational reading!

Paul...G-BPLF...FS 2004...FS Nav... 8-)...!

[DenisH]

Brett: I've read your's and other  tutorials on prop control  and I have the impression the control's chief function  is to increase the prop's "bite" while reducing rpm's?  Is this an over simplification? I realize these are not the sole functions. 

[olderndirt]

you could study the dam things for 20 years and still have no idea about them

Matt

Well said.