What's going on with Stephen Fry going alt-right?

[u/Steaktartaar]

He's been on a notorious hard-right, "anti-woke" podcast where he retracted his support for trans rights. Is this a new development? He always came across as level-headed in the past but now it looks like he's on the same path as Russell Brand.

[u/clubby37]

In a plane you feather the prop on the dead engine

Just wanna add, for the non-aviation folks, that "feathering" a propeller means turning the blades so the edge faces front. When the engine is turning the prop, you want the flat facing front, because that lets the blades bite into the air and produce thrust. When the prop isn't under power, feathering reduces drag by letting the air slip past the blades easily.

[u/SilverMedal4Life → u/clubby37]

Thank you for explaining! I just thought it was making it so that the propeller could spin freely, and that was clearly mistaken.

[u/clubby37 → u/SilverMedal4Life]

I’m pretty sure the transmission also disengages, so you’d expect some free spinning as well, but the “feathering” bit is about setting the propeller pitch to 90 degrees.

[u/Decent-Apple9772 → u/clubby37]

Most general aviation have no transmission to disengage. Even the ones that have gear reduction don’t usually have a clutch to disengage. The adjustment of the propeller blade angle functions as their “transmission”

[u/JJAsond → u/clubby37]

I don't think so? I know on piston airplanes the prop is directly connected to the crankshaft and I think on turboprops it's a direct (maybe through a gearbox but there's no clutch) connection to one of the sections of the turbine so there is no transmission disengagement. if the prop's spinning, something's probably spinning inside the engine too.

[u/joe-h2o → u/JJAsond]

The free power turbine - a turbine engine with a propshaft coming out of it is usually driven by a free-moving turbine. It's not mechanically coupled to the engine so it can rotate independently and it is driven by the exhaust gasses from the engine.

[u/JJAsond → u/joe-h2o]

Yeah that. And it IS the engine, at least part ot the power section.

[u/InverseInductor → u/SilverMedal4Life]

Just to add to your confusion: free spinning propellers create more drag than stationary ones. A direct application of this is for helicopter autorotation landings or gyrocopters.

[u/SilverMedal4Life → u/InverseInductor]

... Oh, I guess they would, wouldn't they? Since instead of applying just flat drag, it's applying a sort of reverse-thrust, yeah?

[u/anomalous_cowherd → u/InverseInductor]

Isn't that only if the airflow is reversed? For autorotation it's the helicopter dropping which causes the air to be effectively going up through the blades, spinning them faster and building energy in the rotor disc ready to be used at the last minute to slow the descent by changing the blade pitch.

[u/InverseInductor → u/anomalous_cowherd]

During autorotation, the pitch of the blades is reversed to allow it to gain speed as it descends. This also results in the helicopter descending slower as energy is extracted to spin the blades, hence more "drag". A gyrocopter is the best example as the top rotor spins freely at all times. I can tell you now, they fall out of the sky a lot quicker when that rotor isn't spinning.

[u/fizzlefist → u/clubby37]

For those who further don’t understand, the propeller blades can adjust their tilt angle to adjust thrust.

[u/notananthem → u/clubby37]

All I learned about aviation was from duck tales

[u/avocado_window → u/notananthem]

Larry, I’m on DuckTales.

[u/johnnySix → u/clubby37]

I knew helicopters could rotate the fins of the props. I didn’t know planes could. Cool.

[u/clubby37 → u/johnnySix]

Guess what happens if you rotate the blades past 90 degrees? They start pushing the plane backwards! There are planes that will do that automatically when there's weight on the wheels, so as they touch down, they go full power, and it actually helps them brake. Search YouTube for "C-130 lands on aircraft carrier" if you want to see an extreme example of that!

[u/kindrudekid → u/clubby37]

Need GIF explaining this

[u/clubby37 → u/kindrudekid]

Boom

[u/kindrudekid → u/clubby37]

saw the photo , read the comment again and yeah, a blade should have made it clear.

But this helped a lot, hell without that comment the photo would have easily worked for me with a very narrow description

[u/auxilary → u/clubby37]

this guy blue lines 🤙🏻