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  #1  
Old 06-11-2018, 09:34 PM
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Dugaru Dugaru is offline
 
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Default Osprey question

So I returned to my home base at New Kent (W96, Richmond, VA USA) the other day to find that a V-22 Osprey was doing touch-and-goes. Or whatever you would call it when a tilt-rotor aircraft practices landings.

The V-22 is just a flat-out amazing aircraft. I was going to join the pattern and land so that I could watch it in action, but then it occurred to me: what is the wake turbulence like from those things?!?

Fearing it might be extra nasty, I motored on for some additional sight-seeing elsewhere.

Any theories on how much room to give to a V-22?
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  #2  
Old 06-11-2018, 10:37 PM
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KRviator KRviator is offline
 
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Quote:
Originally Posted by Dugaru View Post
So I returned to my home base at New Kent (W96, Richmond, VA USA) the other day to find that a V-22 Osprey was doing touch-and-goes. Or whatever you would call it when a tilt-rotor aircraft practices landings.

The V-22 is just a flat-out amazing aircraft. I was going to join the pattern and land so that I could watch it in action, but then it occurred to me: what is the wake turbulence like from those things?!?

Fearing it might be extra nasty, I motored on for some additional sight-seeing elsewhere.

Any theories on how much room to give to a V-22?
Without having anything scientific to base this comment on: A LOT.

IIRC I read somewhere they have quite a high disc loading, compared to a standard fling-wing. Check out this video of a Blackhawk-induced wake vortex crash in Colorado.
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Old 06-12-2018, 03:01 AM
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Beagle Beagle is offline
 
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+1. To quote one of the Indiana Jones movies - You chose wisely.
I was an engineer on the V-22 program in the 80s (yes it has been around that long). Based on its weight and disk loading give it a good amount of time. A few minutes at least.
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  #4  
Old 06-12-2018, 07:15 AM
TS Flightlines TS Flightlines is offline
 
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But you have to admit---its a cool thing to watch!!
Tom
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  #5  
Old 06-12-2018, 07:28 AM
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Low Pass Low Pass is offline
 
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Quote:
Originally Posted by Beagle View Post
+1. To quote one of the Indiana Jones movies - You chose wisely.
I was an engineer on the V-22 program in the 80s (yes it has been around that long). Based on its weight and disk loading give it a good amount of time. A few minutes at least.
For practical purposes, wouldn't the rotor wash be pretty much proportionate to the flying weight of the aircraft? I understand disk loading, but it's really about moving air mass equal to the weight being lifted more-or-less, right? Or is there something about the tiltrotor that would make it significantly different than say, a Sea Stallion. (I'm lucky enough to see all of these things occasionally at my home field. So there's a practical side to the question.)
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  #6  
Old 06-12-2018, 07:30 AM
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I remember the first time I came across one in horizontal flight.
Seeing the size of the props (rotors) my first thought was, "Man, I can't wait to see the landing gear come down!"
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  #7  
Old 06-12-2018, 09:11 AM
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nigelspeedy nigelspeedy is offline
 
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Default Treat rotorcraft with respect

The down wash from a helicopter or tilt rotor is nothing to be trifled with in an RV size aircraft. I treat the wake turbulence from a helicopter like I would that from an airplane 5 times larger. Just like airplanes the wake turbulence from a helicopter is worst when heavy and slow, i.e hovering. Anything the size of a Huey or larger needs to be given a wide berth and/or a couple of minutes after it's departure/landing for the wake to dissipate.
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  #8  
Old 06-12-2018, 02:44 PM
BobTurner BobTurner is offline
 
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Location: Livermore, CA
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Default Bad physics

Quote:
Originally Posted by Low Pass View Post
For practical purposes, wouldn't the rotor wash be pretty much proportionate to the flying weight of the aircraft? I understand disk loading, but it's really about moving air mass equal to the weight being lifted more-or-less, right? )
Its the force-momentum per second-that needs to equal the aircraft weight. This could be a large air mass moving slowly, or a smaller air mass moving quicker. Same as standing behind a jet or prop plane, when both are producing the same thrust. The jet blast can be felt much further away. Since the design constraints on an Osprey (forward propulsion) drive it toward shorter blades, one can expect significant downward air velocities when landing.
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Old 06-12-2018, 06:18 PM
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The V-22 is built in Amarillo, Texas and some of them occasionally come to our airport during cross country flight testing. They are really interesting to watch. The downside for us is they throw serious FOD everywhere! They seem to be worse in that regard than the heavy lift fire fighting choppers that utilize our airport, including Blackhawks and CH-47 Chinooks. Their exhaust is also very hot and can start fires in wooded areas.

The wife and I flew to Amarillo for a weekend get away several years ago and as we were flying over Palo Duro canyon we saw a strange looking aircraft at a distance. It took a minute to register what we were looking at. Later as we were taxiing to the runway at KAMA an Osprey came near us and to say the RV was rocking and rolling was an understatement. I was very concerned because I had seen on the news that several people had been injured by one when it knocked down tree limbs in a park it was flying over.

I have great respect for their rotor wash and wouldn't fly anywhere near one!

Here's a video: https://www.youtube.com/watch?v=i4iw2-n-Uzc
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  #10  
Old 06-12-2018, 07:19 PM
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Default V22 flyby at Sedona

Agree with recommendations above. Here is one passing through Sedona last year.

https://youtu.be/kQXrUhNU2Ao
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