Why Feather a Windmilling Propeller

This video explains why it is beneficial to feather a windmilling propeller.

[@AdamCourville]

There are so many misconceptions about the “rotating disc” that aren’t true and this video is the only one I’ve found that actually shows the real reason for the drag of a windmilling propeller!

[@pejmanjavaheri9758]

Great video! Thank you so much for such a good and thorough explanation!

[@johnroberts7529]

Knockout stuff! Very clear and well thought-out instruction. Many thanks.

[@domnicfernandes5723]

Good 👍 explanation of feathering and reverse thrust..

[@PH-GUS]

Clear video, thanks for the explanation.

[@rajgill1216]

Superb explanation, very clear and concise. Thank you sir!

[@zhihenglou]

great videos, thanks!

[@Liber112]

Thanks mate!

[@abdurrahmanbukhari8114]

Thank you sir🫡

[@kunwarvyomesh6616]

Thank you so much

[@RoddyMcNamee]

You’re very welcome.

[@kunwarvyomesh6616]

It is coming in my exam

[@RoddyMcNamee]

@@kunwarvyomesh6616 Best wishes for your exam.

[@kunwarvyomesh6616]

Are you aeronautical engineer? Or anything else related to aviation

[@RoddyMcNamee]

@@kunwarvyomesh6616 I graduated as an Electronic Engineer, and have worked in aviation for over 20 years. Still learning. Aviation is a strong mix of Aeronautical, Mechanical and Electronic Engineering, exploring each of these subject areas is very fulfilling and interesting. It’s a career you’ll enjoy and the knowledge and skill sets are very transferable to other industries.

[@TheKarinvt]

If the aircraft has lost an engine, in the case of a constant speed propeller, would it be there enough oil pressure present in the governor to being able to change the prop pitch?

[@RoddyMcNamee]

No there wouldn't. Hence the propeller may have a Feathering Spring to push the blades to the Feather position when oil pressure is lost (e.g in the event an engine is lost) or the propeller may have an electrically operated feathering pump that will supply oil at the necessary pressure to move the blades to the feather position.

[@URKAEGEORGEJOY]

can propeller windmilling be used to generate power in electric prop driven engines

[@RoddyMcNamee]

Yes. In fact Pipistrel aircraft have allowed for that in the design of their training aircraft. As the aircraft descends, the prop windmills and recharges the battery. www.pipistrel-aircraft.com/aircraft/electric-flight/alpha-electro/

[@dkoz8321]

After typing in "what is feathering the propeller" in YT search and watching 10 videos on feathering propellers, I am still left with no answer to my question. 'What is feathering the propeller?' Why is the basic definition absent? This is the definition I found on obscure website. "On many variable pitch propellers, the blade pitch can be increased to the point that the chord line of the blade is approximately parallel to the on-coming airflow. This process is referred to as feathering."

[@Mikinct]

Wonder if it’s good to also feather the good engine in twin prop engine?

[@benwilms3942]

But why does windmilling cause more drag? Rotationg or not the prop still must displace the same volume of atmosphere at the same rate, other than profile drag reduced, how would spinning or not spinning change that?

[@RoddyMcNamee]

@Ben Wilms a windmilling prop will have a negative angle of attack. A negative angle of attack will create negative thrust I.e drag.

[@monolith1337]

Primarily because of the work the propeller must do to turn the engine over, since the engine is an air pump when it's not running, you're just using your airspeed to turn the engine over while the prop is wind milling.

[@rohvlogs8232]

Hi

[@Mikinct]

I imagine one turns off prop sync once loss off one engine?

[@RoddyMcNamee]

Once the RPM of engines varies by an amount e.g difference of 50 RPM or 100 RPM the system will disengage.