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Settling with Power
#31
flaxen, that is great that you are able to practice and experiment with SWP/VRS with the sim. The bad part about it is that you don't have any depth perception being 2 dimensional and you don't detect closure rate as easily but there is actually a good side to that. Since you don't have the depth perception or peripheral vision you have to pay more attention to the instruments and will learn the airspeeds, decent rates and power settings that will get you into SWP. See, the simulator us a good thing. Keep practicing.
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#32
True, 2D depth perception isn't as good but it's not debilitating either in my opinion because I have a TrackIR5 head tracking device and I love it! Without tracking, the perspective is limited to looking forward or at 45° angles w/ the hat switch on my cyclic, yuck! With tracking, I can comfortably and smoothly look around with complete freedom.

That helps a lot with the "look and feel" of the sim and minimizes the fact it's just a 2D image. For example, I can look out the windows to see my LZ and setup the final leg of my approach more accurately, and looking down & around while making the approach gives me a pretty fair idea of closure rates (tho I watch airspeed too). Finally, while ending the flare I see the shadow of my skids coming closer and can judge exactly how much collective to pull for a feather-soft landing... All of which is nearly impossible with the fixed / forward-looking perspective.

I also have Alfredo's Mosquito XE model for X-Plane which doesn't use X-Plane's 3D cockpit features (which is good thing). Instead, the actual model includes the cockpit with working instruments and everything, making it the best model for this TrackIR device in X-Plane hands-down because there's no sudden end to the cockpit graphics no matter where you look (unlike all included models). Alfredo's model is nearly perfect but did require some tweaks to get flying accurately.

I've racked up almost 90 hours in simulation so far (40hrs w/ the Pro Flight Trainer + TrackIR setup) and I judge that experience as invaluable. I recommend this setup to others in a similar situation too. I've learned to fly with the correct controls including manual throttle and even conquered my deathgrip before ever sitting down to fly for real... Man-oh-man do I ever look forward to that day!
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#33
flaxan,

That is really cool man. I have never seen the X-Plane program but it sounds like it is really pretty good. I talked to Fly Guy a few days ago and he said he really likes it as well. I'll have to look into it. Thanks for the info.
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#34
Ray W. Prouty's "Helicopter Aerodynamics Vol. 2" Ch53, Pg 197-200, covers this. He says this:

"Thus it is not the action of pulling up on the collective pitch that triggers the phenomenon. It is that a modest control input is incapable of changeing the final result. Only when he applies enough collective pitch to reduce the rate of descent to a stable region will he be able to recover (providing there is enough engine power to keep the rotor speed up)."

I to like bryancobb had learned it as if you had greater than 100% power available, then you could get out of it. Most designers never want to give more power than needed for the customer so greater than 100% almost never applies. If the designers did, it would be heavier than needed or fuel burn would be higher than needed. When i say heavier, its not only the weight of the engine, but all the components that will be driven by the overly powered engine. On the UH-60L model, we have 120% TQ available to us assuming the enviornmental conditions allow the power production.

"Only God understands turbulance"- Theodore von Karman, famed aerodynamicist
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#35
during my r-22 training we practiced swp. you need three things to get into swp. speed less than 30 kts, decent rate higher than 300 fpm, and power on. remove any one to get out of swp. we would increase speed during ower demonstrations. 
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#36
Thanks TurboEddy, I didn't realize removing power would get you out also. Maybe that is why it's called SWPower, duh me. My instructor said "Notice the shudder" ... yeah, that part is scary and memorable. The fix was easy, lower collective, forward cyclic, and fly out of it into clean air. If I remember right. Maybe he said reduce power? No, need to keep RPM, but then when you lower collective RPM goes up, forward stick RPM goes down, balance? Reduce power if RPM gets too high - but I guess getting out of the SWP and maintaining RPM is first priority.

HAS ANYONE practiced SWP in a Mosquito??????

Does it shudder like a R22?

Do other helicopters shudder like an R22?

Is lowering collective together with forward stick the right way to get out?
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#37
larry, the problem is you cant reduce your rate of descent!!!!!! so increase airspeed and/or lower collective. in other words fly out or auto out of swp. this is a good discussion of heli aerodynamics. 
im sure it would shudder like a r-22. 
when you lower the collective to the bottom rpm is based on weight. higher weight = higher rpm. if i have 4 persons in the r-44 i better during auto i know i will need some pitch on the blades to keep the rpms from going into the red.  in a turn you will spin up more rpms so a bit more pitch on the blades is needed too. 

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#38
Correct me if this is wrong, but, I believe someone said earlier that SWP is a TRUE emergency and it is not advisable to practice in a Mosquito.  You have a lot invested (including you life) to practice a situation that my not be recoverable.
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#39
Hey guys, this is a good discussion but I would like to add a little more helpful insight. The corrective action for getting out of SWP is to lower the collective and then apply forward cyclic to attempt to fly out of it. I know you guys are all straight on that. Here's the problem. In the most likely of scenarios for getting into SWP you would be too low to successfully get out of it which is another reason to avoid it. Think about it, why would you be in a scenario where you have no airspeed and a high rate of descent from an altitude high enough to recover from entry into SWP unless you were just trying to get into it? How many of you are worried about going out and entering a vertical descent from a 100' hover? Exactly, you would never put yourself in that situation not just because of SWP but because you are way into the dead man's curve. This supports my point about not practicing SWP but having a full understanding of what it is and that it is a possibility that exists and knowing how to keep yourselves out of it.
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#40
Pfranc - 9/24/2010 1:33 PM

Thanks TurboEddy, I didn't realize removing power would get you out also. Maybe that is why it's called SWPower, duh me. My instructor said "Notice the shudder" ... yeah, that part is scary and memorable. The fix was easy, lower collective, forward cyclic, and fly out of it into clean air. If I remember right. Maybe he said reduce power? No, need to keep RPM, but then when you lower collective RPM goes up, forward stick RPM goes down, balance? Reduce power if RPM gets too high - but I guess getting out of the SWP and maintaining RPM is first priority.

HAS ANYONE practiced SWP in a Mosquito??????

Does it shudder like a R22?

Do other helicopters shudder like an R22?

Is lowering collective together with forward stick the right way to get out?

Don't confuse that "Shudder" with the onset of SWP! You will feel shuddering with SWP, but the shuddering most folks are feeling during SWP demonstrations in an R-22 is caused by being right AT ETL airspeed during the descent!
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