Mailing List flyrotary@lancaironline.net Message #48830
From: Al Gietzen <ALVentures@cox.net>
Subject: RE: [FlyRotary] Re: off subject - RV spin characteristics
Date: Wed, 21 Oct 2009 15:59:53 -0800
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

This is a man of TALL confidence!

 

Anyone want to come along and hold the camera?

 

Ah-h-h; maybe not.

Al

 

 

Fun Stuff. 

 

I have pretty well explored the spin characteristics of my RV-6.  Every RV is different.  You never really got one going in that video, not even a full rotation best I could tell.  Mine are different depending on whether I spin toward the normally heavy wing, or the light wing.  They are steeper toward the heavy wing and also steeper with a pax.  Much better toward the lighter wing - makes for a nice flat spin.  I have not tried aileron in the direction of spin - it is fast enough without it.

 

Gradually approach the stall in level flight.  Some slight rudder and aileron to partly compensate for the heavy wing.  At stall buffet, throttle to idle, stick full aft and full rudder.  At first it is steep pitch down and bobble like what you show.  After about 2 turns it flattens out and the rate of turn increases.  After about 4-6 turns it is fully developed and the centrifugal force is quite noticeable, turn rate seems about 1.5 seconds per rotation, pitch down is about 20 deg. and I am loosing about 400 feet per rotation (the first couple turns and last couple turns it is more than that).   At about 6-8 turns I get oil pressure and fuel pressure low alarms from the gas and oil all being flung outboard away from the pickups.  That is the farthest I take it.

 

It takes me 3-5 turns to get out of a fully developed spin (before the spin develops, it is nearly instant).  Start with opposite rudder and stick to neutral, I have to forcibly hold the stick in the neutral position.  As the rotation slows and starts to reverse direction I need to smartly but not too fast apply forward stick.  Too fast, and the elevator stalls and mushes.  Too slow and I have missed the window of opportunity and the spin reverses direction.  I can help by easing the rudder a little when the rotation is slow.  The Idea is to get the rudder and elevator flying again, then get the nose down while flying strait. It is sort of a feel thing, but it is a little scary, disorienting, and the trees are getting bigger and engine alarms are going off.  I did quite a few spins working up to this point.  It was a lot of practice getting used to the feel of the airplane and how it responds and getting comfortable with the sights and sounds.

 

Once that elevator catches, it pitches down and out.  I hold the pitch down a couple seconds because there is not power from the engine yet and I want to keep it at idle while the oil system re-pressurises.

 

Probably not really smart, but a whole lot of fun. 

 

Sorry I don't have any video.  Anyone want to come along and hold the camera?


--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net

On Wed, Oct 21, 2009 at 10:13 AM, kevin lane <n3773@comcast.net> wrote:

one day I video recorded what happens in my RV-6A when I attempt to stall/spin.  with the stick held full back and neutral, rudders neutral, power off, you can see the ride I get.  it is actually a lot more bouncy and shaking than the video portrays.  I would never do this with say, my wife, on board.  eventually the left wing drops a lot, speed picks up and the plane dives and pulls up, ready to start this routine all over again.  at this point I give full right rudder to initiate a spin, recovering several thousand feet below the 5000' starting altitude.  I have tried the "flying leaf" maneuvers [only rudder corrections to a stall] before, and again, never get into a full stall.   

 note - RV spin recovery requires neutral or forward stick along with opposite rudder.  this is not like the T-craft I learned to fly in.  pushing the stick in the direction of the spin will really wind it up.  don't do this!  Van himself told me that! [afterwards]   stick to 1 or 2 revolutions[ not 6], that's all Vans has ever tested.     kevin

 



 

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