Prop...

[MachFly]

You don't see this everyday.

larger version

 

[Sac Arrow]

It's slightly better than looking forward and seeing the same thing.

 

[Ted]

It appears the prop isn't feathered. Curious, are the DA42s built that way?

 

[bluesky74656]

It appears the prop isn't feathered. Curious, are the DA42s built that way?

The first question would be is the prop actually stopped, or did the shutter speed match the prop speed exactly. I've been pretty close before.

 

[airguy]

It appears the prop isn't feathered. Curious, are the DA42s built that way?

Yup - that was my immediate reaction too.

 

[timwinters]

The first question would be is the prop actually stopped, or did the shutter speed match the prop speed exactly. I've been pretty close before.

Huh?

I guess a photographer will have to explain that one to me 'cause I don't see how it's possible...unless you're spinning the camera on your finger at 2400 RPM or so.

 

[fgcason]

I guess a photographer will have to explain that one to me 'cause I don't see how it's possible...unless you're spinning the camera on your finger at 2400 RPM or so.

Fast shutter speed. It's the same thing as freezing individual drops of water during a splash or a bullet coming out of a barrel.

 

[timwinters]

Fast shutter speed. It's the same thing as freezing individual drops of water during a splash or a bullet coming out of a barrel.

Oh, I fully understand how that works. That's not what I couldn't understand though. What was said was:

The first question would be is the prop actually stopped, or did the shutter speed match the prop speed exactly. I've been pretty close before.

"Shutter speed match the prop speed exactly" is what I had problems wrapping my brain around. I gotta feeling there's no such thing but am certainly willing to learn if there is.

 

[Ted]

The prop is not feathered because the picture was taken right before the restart, it was feathered a few seconds before that. On that picture the prop is windmilling, so it's not actually stopped (but it is on this one).

Feathered:

larger version





It feathers automatically when you shut down the engine while being airborne.

Gotcha! Unfeathering accumulators, I'm guessing?

Is yours the Thielert or Austro variant?

 

[Ted]

That's the thing that releases pressure to unfeather the prop (when the engine is off) so it would start windmilling, right?

Correct. Twins that have unfeathering accumulators (many don't) will use them to get the prop windmilling, thus making a mid-air restart easier.

 

[MachFly]

Correct. Twins that have unfeathering accumulators (many don't) will use them to get the prop windmilling, thus making a mid-air restart easier.

Right, was not sure that I'm associating the term to the right system. So yeah, that's what it has.