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  #11  
Old 07-05-2022, 03:35 PM
rv6n6r's Avatar
rv6n6r rv6n6r is offline
 
Join Date: May 2007
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Quote:
Originally Posted by RFSchaller View Post
Make sure you have a good story made up for the NTSB if there’s an issue!😝
If I'm not mistaken, in Hans's case that would instead be the RvTV.

If it were in the US I'd be recommending doing this over some place like the Black Rock or Alvord desert. Actually pretty fun and good practice to do real prop-stopped dead stick landings. I can't speak to the whole Rotax restarting bit however.
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  #12  
Old 07-06-2022, 06:34 AM
HansLab HansLab is offline
 
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Y'all were right: the Rotax did not start in dive. Tried it out today. Fairly good glide scope though, I feel confident when the thing stops. Hope I have the guts to slow down a bit to stop the prop (when heigh enough), for that makes a big difference.
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  #13  
Old 07-06-2022, 10:45 AM
RFSchaller RFSchaller is offline
 
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The ENGINE AIR RESTART emergency procedure in the POH says the prop will not windmill below 80 KTS. It doesn’t say whether it would start to windmill again by going above 80 KTS if it stops.
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  #14  
Old 07-06-2022, 11:50 AM
NinerBikes NinerBikes is offline
 
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11 : 1 compression ratio for the engine and the reduction gearbox is a lot of resistance to overcome to get the prop spinning again.

Maybe someone will try it this summer when the air density is low, and then again this winter on a cold day, when the air density is high.
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  #15  
Old 07-06-2022, 07:59 PM
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rtlongdon rtlongdon is offline
 
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Location: Stanwood, WA
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Default What was the glide ratio?

Quote:
Originally Posted by HansLab View Post
Y'all were right: the Rotax did not start in dive. Tried it out today. Fairly good glide scope though, I feel confident when the thing stops. Hope I have the guts to slow down a bit to stop the prop (when heigh enough), for that makes a big difference.
So what glide ratio did you have (I'll assume you were at best glide speed) with the prop windmilling and engine shut down?
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  #16  
Old 07-06-2022, 11:53 PM
NinerBikes NinerBikes is offline
 
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Originally Posted by rtlongdon View Post
So what glide ratio did you have (I'll assume you were at best glide speed) with the prop windmilling and engine shut down?
Best glide speed is 63 kts... well below 80kts to stop the prop from windmilling. It should be in your POH.
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  #17  
Old 07-07-2022, 11:48 AM
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rtlongdon rtlongdon is offline
 
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Quote:
Originally Posted by NinerBikes View Post
Best glide speed is 63 kts... well below 80kts to stop the prop from windmilling. It should be in your POH.

Quote:
Y'all were right: the Rotax did not start in dive. Tried it out today. Fairly good glide scope though, I feel confident when the thing stops. Hope I have the guts to slow down a bit to stop the prop (when heigh enough), for that makes a big difference.
I read the OP's post to mean that he had not yet achieved prop stoppage, but he hoped to once he "had the guts". Maybe I just misinterpreted what he was trying to say, the post was a little confusing for me, might just be my mistake! I'm well aware of best glide speed and where to find it, but thanks anyway!

I've seen Larry's video on his dead stick demo in a -12 and he had to slow to 65 knots to stop the prop- there goes the 80 knot thing! I've heard of "someone" that had to get to about 58 knots to stop it
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Last edited by rtlongdon : 07-07-2022 at 11:55 AM.
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  #18  
Old 07-07-2022, 09:29 PM
RFSchaller RFSchaller is offline
 
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Seems a moot point wondering at what airspeed the prop stops. If your engine fails you should pitch for best glide and try a restart with the starter. If that doesn’t work you probably won’t get it restarted with airflow. I had an engine stop once due to a carburetor that wasn’t seated in the socket properly. Fortunately it restarted with the starter.
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  #19  
Old 07-07-2022, 10:53 PM
seagull seagull is offline
 
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Why all the guessing and speculation? Did anyone watch this video?

https://www.youtube.com/watch?v=VwPAiuu1dxw
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