REFLECTOR: Trailing Edge Aileron Fence and door open emergency procedures

Scott Derrick reflector@tvbf.org
Fri, 01 Aug 2003 18:31:53 -0600


Hay Greg!

Soon as I finish my exhaust system upgrade which is requiring a major 
cowling redesign I may give um a go!

You know I'm always looking for ways to reduce my hot and high altitude 
takeoff distances!

Scott



Greg Poole wrote:

> Hi Scott,
>  
> You're flying & obviously a motivated soul....when you going to put this 
> information to the test and report back to all us curious builders? ;^ )
> Greg in Sydney.
> STD RG Elite
>  
> ----- Original Message -----
> From: "Scott Derrick" <scott@tnstaafl.net <mailto:scott@tnstaafl.net>>
> To: <reflector@tvbf.org <mailto:reflector@tvbf.org>>
> Sent: Friday, August 01, 2003 12:07 PM
> Subject: Re: REFLECTOR: Trailing Edge Aileron Fence and door open 
> emergency procedures
> 
>  > Rodney,
>  >
>  > Thanks a bunch for the info and pics!
>  >
>  > Scott
>  >
>  > Rodney Brim wrote:
>  > > Hi,
>  > > Sorry I'm a month late in responding.  Am fighting cancer and low 
> energy and
>  > > don't get to the plane much to measure or take pictures.  But I 
> recently did
>  > > and here they are.  I also looked up my original research.  The 
> take-off
>  > > roll was reduced by over 20% not 15%.  Actually at the time I 
> measured it,
>  > > it was roughly 22%.
>  > >
>  > > Before I do the numbers and picture story I want to suggest you all 
> add a
>  > > comment to your emergency procedures.
>  > >
>  > > 1. If the door pops open fully, DO NOT TURN AWAY FROM THE OPEN DOOR.
>  > >
>  > > If you, like I, ever have that experience.  You will start a rapid 
> roll away
>  > > from the door to an inverted position.  For me the door opened 
> slightly as I
>  > > departed... with the gear coming up it pressurized the cabin and 
> pops the
>  > > door wide open, and then if you turn away from the door (to head 
> back to the
>  > > airport) it wants to roll and spin into the ground, in my case at 
> about 200
>  > > feet.  Opposite rudder and aileron will hold you at a 60 degree 
> bank angle,
>  > > but won't get you out of the fix as you're going to stall in that
>  > > configuration.  There is a way out, but that's another 
> conversation.  OK
>  > > back to trailing edge fence.
>  > >
>  > > I've attached a couple of pictures.  They are located on the 
> inboard side of
>  > > the ailerons.  They point directly into the wind.  If you are 
> testing, you
>  > > can cut them out of plexiglass clipboards and hot glue them in 
> place.  I did
>  > > for all of my testing.  I also wrote this up in an article in 
> Velocity Views
>  > > a couple of years ago.
>  > >
>  > > Specs:
>  > > 1. Position.  They are located on the inside of the aileron, but face
>  > > directly into the wind, not the angle of the aileron.
>  > > 2. They extend back from the trailing edge 1.5 inches, and 5 inches 
> above
>  > > the trailing edge and 2.5 inches below.
>  > > 3. From that position the top and bottom dive into the wing.  The 
> length of
>  > > the top (from wing to end of trailing edge) is 12 inches.  The 
> bottom is 9
>  > > inches, but note that's because the trailing edge of the stall 
> fence is not
>  > > perpendicular to the ground.  Instead of dropping at a 90 degree 
> angle at
>  > > the top (which may be a preferable design), I slopped mine forward 
> at a 70
>  > > degree angle.
>  > >
>  > > |---- 12 "------------------  70
>  > >                           -
>  > >                          -
>  > >                         -
>  > >       |--- 9" ----------|
>  > >
>  > >
>  > > That's roughly the shape in a text format, except the bottom slopes 
> up to
>  > > meet the underside of the wing and the top slopes down to meet the 
> top.  But
>  > > both of those may be better served by having a longer run into the 
> wing.
>  > > Klaus was the one who helped me with this and it wasn't a value at 
> the time.
>  > >
>  > > Hope that helps.  Fly safe.
>  > >
>  > >
>  > >
>  > > Rodney Brim,
>  > >
>  > >
>  > > -----Original Message-----
>  > > From: reflector-admin@tvbf.org <mailto:reflector-admin@tvbf.org> 
> [mailto:reflector-admin@tvbf.org]On
>  > > Behalf Of Rene Dugas
>  > > Sent: Thursday, May 29, 2003 3:24 PM
>  > > To: reflector@tvbf.org <mailto:reflector@tvbf.org>
>  > > Subject: RE: REFLECTOR:Aileron Fence
>  > >
>  > >
>  > > I would be interested in dimensions and locations  of fences.
>  > > Thanks,
>  > > Rene'
>  > > XL RG
>  > > rdugas@bayou.com <mailto:rdugas@bayou.com>
>  > >
>  > > -----Original Message-----
>  > > From: reflector-admin@tvbf.org <mailto:reflector-admin@tvbf.org> 
> [mailto:reflector-admin@tvbf.org] On
>  > > Behalf Of Rodney Brim
>  > > Sent: Thursday, May 22, 2003 9:12 PM
>  > > To: reflector@tvbf.org <mailto:reflector@tvbf.org>
>  > > Subject: RE: REFLECTOR:Aileron Fence
>  > >
>  > > Hi Chuck,
>  > >
>  > > 1. I got a >15% reduction in take-off roll on my final version of the
>  > > fences.  Looks like that is attributable to driving the air more
>  > > directly
>  > > over the wing at slower speeds and not having it slide down the wing,
>  > > which
>  > > if you do some dirty oil tests you will see that it is doing.
>  > > 2. It doesn't effect your stall, that's all governed by the canard.
>  > > 3. It feels like it reduces roll rate slightly.  I didn't measure it,
>  > > but
>  > > you can tell the plane has more tail feathers, especially as you move
>  > > the
>  > > fences out along the wing, which I would not suggest.  To me it makes
>  > > the
>  > > plane feel more stable.
>  > > 4. Reduction in cruise speed is dependent upon height of the fences and
>  > > location.  At the location and height I have them, I have no reduction
>  > > in
>  > > cruise speed.
>  > >
>  > > 5. I think they should be standard on the kit... but then what do I
>  > > know.  I
>  > > think everyone should move to forward hinging doors;)
>  > >
>  > > Rodney Brim,
>  > > PS I have a picture and dimensions if you want them.  They probably
>  > > helped
>  > > save my neck as I had an ugly door pop, going inverted stall at 200 
> feet
>  > > coming off a runway a couple of years ago... sometimes you can use all
>  > > the
>  > > stability and directional control you can get your hands on.
>  > >
>  > >
>  > > -----Original Message-----
>  > > From: reflector-admin@tvbf.org <mailto:reflector-admin@tvbf.org> 
> [mailto:reflector-admin@tvbf.org]On
>  > > Behalf Of Chuck Jensen
>  > > Sent: Thursday, May 22, 2003 7:30 AM
>  > > To: 'reflector@tvbf.org' <mailto:'reflector@tvbf.org'>
>  > > Subject: REFLECTOR:Aileron Fence
>  > >
>  > >
>  > >>From the Newsletter, some preliminary flight testing seemed to show
>  > > than an
>  > > inboard aileron fence had merit for reducing takeoff distance,
>  > > increasing
>  > > climb rate and perhaps reducing stall speed while not affecting cruise
>  > > performance and turning characteristics.  Has this become a 
> concensus or
>  > > is
>  > > the jury still out?  And, is there a standard template for such a 
> fence?
>  > >
>  > > Chuck Jensen
>  > > XL RG
>  > >
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