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VGs feathers on an 801

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keystone(at)gci.net
Guest

Posted: Sun Jan 28, 2007 9:54 pm Post subject: VGs feathers on an 801

Hi



I got about 30 minutes of weather good enough to fly this afternoon.  The 

leading edge slats are off and the feather VGs are on.  It seemed to want to 

climb like a home sick angel.  I was light (1600 lbs), 30 gallons of fuel 

and 230 pounds of me with nothing else.  I saw 900 FPM at 80 MPH.  Density 

altitude on the ground was -1500'.  The plane flew good I did not notice any 

CG issues.



                                  Before                         After

Cruise                        103 MPH                   111 MPH both 

adjusted to 4500' standard temp at 85% power 10.5 GPH leaned to 150 ROP

No flaps stall               None                          Buffet at 58, 

stall 50 indicated and GPS

Full flaps stall              None I assumed 38    45 indicated 49 GPS (only 

done once)

Approach speed         50                              58

Take off run                Very short                    Much longer

                                  250'                            350'

Landing distance: the breaking action was poor so I did not measure.



I need to fly more in this configuration.  The fog moved in and I was going 

to bust FARs so I landed.



It is weird flying a plane that will actually stall!  I think it may be a 

better plane to teach the kids to fly.  They would learn what stalls feels 

like.  The flaperons are effective even in the stall.



The VG spacing for the outboard 3' is at 60 MM and the rest are at 90 mm 

spacing.  I may change the spacing to 60 MM for the length of the "aileron". 

This hopefully will still give aileron control and inner part of wing 

stalling first but still lower speeds.



Bill Wilcox

N801BW

Valdez, Alaska

280 hrs

Waiting for a flying day.  Going to replace the VGs on the tail with more, 

smaller VGs with less angle.



---

n801bh(at)netzero.com
Guest

Posted: Mon Jan 29, 2007 6:08 am Post subject: VGs feathers on an 801

Good info Bill. Thanks for the feedback.

 

do not archive



Ben Haas

N801BH

www.haaspowerair.com



-- Keystone Engineering LLC <keystone(at)gci.net> wrote:

--> Zenith-List message posted by: Keystone Engineering LLC <keystone(at)gci.net>



Hi



I got about 30 minutes of weather good enough to fly this afternoon.  The 

leading edge slats are off and the feather VGs are on.  It seemed to want to 

climb like a home sick angel.  I was light (1600 lbs), 30 gallons of fuel 

and 230 pounds of me with nothing else.  I saw 900 FPM at 80 MPH.  Density 

altitude on the ground was -1500'.  The plane flew good I did not notice any 

CG issues.



                                  Before                         After

Cruise                        103 MPH                   111 MPH both 

adjusted to 4500' standard temp at 85% power 10.5 GPH leaned to 150 ROP

No flaps stall               None                          Buffet at 58, 

stall 50 indicated and GPS

Full flaps stall              None I assumed 38    45 indicated 49 GPS (only 

done once)

Approach speed         50                              58

Take off run                Very short                    Much longer

                                  250'                            350'

Landing distance: the breaking action was poor so I did not measure.



I need to fly more in this configuration.  The fog moved in and I was going 

to bust FARs so I landed.



It is weird flying a plane that will actually stall!  I think it may be a 

better plane to teach the kids to fly.  They would learn what stalls feels 

like.  The flaperons are effective even in the stall.



The VG spacing for the outboard 3' is at 60 MM and the rest are at 90 mm 

spacing.  I may change the spacing to 60 MM for the length of the "aileron". 

This hopefully will still give aileron control and inner part of wing 

stalling first but still lower speeds.



Bill Wilcox

N801BW

Valdez, Alaska

280 hrs

Waiting for a flying day.  Going to replace the VGs on the tail with more, 

smaller VGs with less angle.



---

pacificpainting(at)comcas
Guest

Posted: Mon Jan 29, 2007 7:58 am Post subject: VGs feathers on an 801

Bill,

  

 So, you're saying the before is with slats and the  after is without slats but with VG's? Correct?

  

 Dave in Salem

  

  

 [quote]   ---

vgstol(at)bigpond.net.au
Guest

Posted: Mon Jan 29, 2007 2:01 pm Post subject: VGs feathers on an 801

Gday Bill,



Well, that's interesting......

Yeh, one of the first things you do notice from removing slats is the 

increase in climb - all that power (about 23% measured on the Savannah) that 

was used to overcome the drag is now available for climb.



A bit disappointed in the stall characteristics tho - our 701's and 

Savannahs just get back to a high descent mush, much like with the slats. 

What's the position of your Feathers now??  It sounds like they could be

better even farther forward - I'd try them at 7%.



Wishing you some good weather for further experimenting.  Here we have lots 

of 37*C (99*F) weather  to spare, but even if we could send some of it to 

you, I guess it would be a mess on top of  20 ft of snow.......



JG

---

keystone(at)gci.net
Guest

Posted: Tue Jan 30, 2007 2:24 pm Post subject: VGs feathers on an 801

Hi

  

 I moved the feathers VGs about an inch farther  forward.  The chord is 57".  The front of the VG is at 3" and the back  is at 4" behind the leading edge of the wing (along the chord).  3.4" is 6%  of the chord.  

  

 I also installed more Vgs.  I continued the 60  mm spacing to the second leading edge slat bracked from the wing tip.  The  rest of the wing is on a 90 mm spacing.

  

 The density altitude was -2500' at take off.   I was light about 1600 lbs.  Again it climbed like a home sick angle.   I was getting 800-900 FPM at 80 mph.

  

 The stall speed are the same as they were in my  report on Monday.  

  

 Flaps up 50

 Flaps down 45

  

 The flaperons were effective even when the wing is  stalled.

  

 I may move them to 5% or I may change the VGs  on the tail to see if that changes anything.  

  

 Any suggestions? 

  

  Bill Wilcox

 N801BW

 Valdez,  Alaska

 280 hrs

 Slats still off

 Doing some head scratching, trying to figure out what to do next.

  

  

  

 

Time: 02:01:08 PM PST US

From:  "JG" <vgstol(at)bigpond.net.au (vgstol(at)bigpond.net.au)>

Subject: Re: Re: VGs feathers  on an 801

Gday Bill,



Well, that's interesting......

Yeh,  one of the first things you do notice from removing slats is the 

increase in  climb - all that power (about 23% measured on the Savannah) that 

was used to  overcome the drag is now available for climb.



A bit disappointed in the  stall characteristics tho - our 701's and 

Savannahs just get back to a high  descent mush, much like with the slats. 

What's the position of your Feathers  now??  It sounds like they could be

better even farther forward - I'd  try them at 7%.



Wishing you some good weather for further  experimenting.  Here we have lots 

of 37*C (99*F) weather  to  spare, but even if we could send some of it to 

you, I guess it would be a  mess on top of  20 ft of snow.......



JG

----- Original  Message ----- 

From: "Keystone Engineering LLC" <keystone(at)gci.net (keystone(at)gci.net)>

Sent: Monday, January 29, 2007 4:54 PM

Subject:  Re: VGs feathers on an 801

[quote] <keystone(at)gci.net (keystone(at)gci.net)>



 Hi



 I got about 30 minutes of weather  good enough to fly this afternoon.  The 

 leading edge slats are off  and the feather VGs are on.  It seemed to want 

 to climb like a  home sick angel.  I was light (1600 lbs), 30 gallons of 

 fuel and  230 pounds of me with nothing else.  I saw 900 FPM at 80 MPH. 

  Density altitude on the ground was -1500'.  The plane flew good I did not  

 notice any CG  issues.



                                   Before                          After

  Cruise                         103  MPH                    111 MPH both 

 adjusted to 4500' standard temp at 85% power 10.5 GPH  leaned to 150 ROP

 No flaps  stall                None                           Buffet at 58, 

 stall 50 indicated and GPS

 Full flaps  stall               None I assumed 38    45 indicated 49 GPS 

 (only done  once)

 Approach speed          50                               58

 Take off  run                 Very  short                     Much  longer

                                   250'                             350'

 Landing distance: the breaking action was poor so I did not  measure.



 I need to fly more in this configuration.  The fog  moved in and I was 

 going to bust FARs so I landed.



 It  is weird flying a plane that will actually stall!  I think it may be a  

 better plane to teach the kids to fly.  They would learn what  stalls feels 

 like.  The flaperons are effective even in the  stall.



 The VG spacing for the outboard 3' is at 60 MM and the  rest are at 90 mm 

 spacing.  I may change the spacing to 60 MM for  the length of the 

 "aileron". This hopefully will still give aileron  control and inner part 

 of wing stalling first but still lower  speeds.



 Bill Wilcox

 N801BW

 Valdez,  Alaska

 280 hrs

 Waiting for a flying day.  Going to replace  the VGs on the tail with more, 

 smaller VGs with less  angle.

 ---

pacificpainting(at)comcas
Guest

Posted: Tue Jan 30, 2007 2:40 pm Post subject: VGs feathers on an 801

Bill,

  

 I've kind of been keeping up on the slat issue.  Does anyone use VG's with slats? Does the slat change the airflow over the wing  where the VG's have effect? These are just questions I don't really know  anything about. I plan on using my slats anyway, but I'm curious  about  this issue.

  

 Thanks,

  

 Dave in Salem - almost done with the  wings.

  

  

 [quote]   ---

vgstol(at)bigpond.net.au
Guest

Posted: Tue Jan 30, 2007 3:01 pm Post subject: VGs feathers on an 801

Dave,

  

 Yeh, I tried the VGs with  slats.  They make no difference in that situation because the  slats already give the accelerated airflow that stays attached at high  AoA.  The slats do that job well, it's just that they bring a very high  drag that stays at all speeds including climb - note Bill's observation about  "climbing like an angel" - it's the reduction in drag by removing the slats that  gives the improvement.

  

 JG

 [quote]   ---

pacificpainting(at)comcas
Guest

Posted: Tue Jan 30, 2007 3:15 pm Post subject: VGs feathers on an 801

THANKS. THAT CLEARS THINGS UP.

  

  

 [quote]   ---

keystone(at)gci.net
Guest

Posted: Tue Jan 30, 2007 4:57 pm Post subject: VGs feathers on an 801

Dave

  

 My understanding is "stacking" high lift devices on  top of each other does not add significantly to the performance.   

  

 I plan on putting the slats back on over the  VGs.  I'm planning on having the take off and landing distances  measured in both configurations at the Valdez May Day Fly-in.   

  

 Bill

  

  

[quote][b]Bill,  I've kind of been keeping up on the slat issue. Does anyone use VG's  with slats? Does the slat change the airflow over the wing where the  VG's have effect? These are just questions I don't really know anything  about. I plan on using my slats anyway, but I'm curious  about this  issue.  Thanks,  Dave in Salem - almost done with the wings.     ---

pacificpainting(at)comcas
Guest

Posted: Tue Jan 30, 2007 7:32 pm Post subject: VGs feathers on an 801

Bill,

  

 Be sure and post what your results are for the take  off and landings. I'm more interested in those numbers than anything else. I  think my plane will be configured similar to yours when I'm finished. I have a  picture of you and your plane on the wall in the shop. It's nice to see what the  finished product will look like. Keeps me motivated. 

  

 Dave

  

  

 [quote]   ---

keystone(at)gci.net
Guest

Posted: Fri Feb 09, 2007 11:37 am Post subject: VGs feathers on an 801

I finally  got time to add 100 VGs to my tail to see if that makes a difference.  It  did not seem to make a difference.  Here is a summary of my testing.   I only stalled the plane 3 or 4 times in each configuration.  The numbers  should be within a mile an hr or two.  The winds have been light when I  have done the testing.  I used GPS speeds.  To calculate air speeds at  high altitudes I assumed the plane's speed would increase 3% per 1000' rise in  altitude.   

  

Removed Leading Edge Slats off  the CH 801 

 <?xml:namespace prefix = o  ns = "urn:schemas-microsoft-com:office:office" /> 

Installed home made VGs 10% of  chord and at a 45 degree angle 

Stall clean             55 

Stall dirty             43 

Cruise              I 108 MPH GPS 103 MPH  

Density altitude at 3000’             +500’  

Cruise at 4500’ Standard day                  115 MPH 

  

Installed feathers at 10% of  chord at 12 degrees 

Stall clean             51 

Stall dirty             45 

Cruise I 110 MPH    GPS 104 MPH 

Density Altitude at 3000’             +1500 

Cruise at 4500’ Standard day                  113 MPH 

  

Installed Feathers at 6% of chord  at 12 degrees 

Stall clean             50 

Stall dirty             45 

Cruise not measured 

  

Installed Feathers at 6% of chord  at 12 degrees 

Removed large VGs from tail  installed 100 smaller home made VGs at a 15 degree angle 

Stall clean             50 

Stall dirty             45 

Cruise I 105 MPH    GPS 103 

Density altitude at 3000’              +1000’ Cruise  at 4500’ standard day                   114 MPH

 Take  off and landing distances are definitely  longer.  They are a lot shorter than a Cessna but...

  

 If you factor the cruise to 6000' you would be 122 MPH.   The plane seems slipperier.  Not like a Bonanza or Mooney but more slippery  that it was.  

  

 Before VGs I used 50 as my final approach speed now I need to  use 58 mph.  

  

 Is loosing 8 mph on the bottom end worth gaining 10 mph  on the top end?

  

 Bill Wilcox

 N801BW

 280 hrs

 Valdez, Ak

 Scratching head contemplating installing fairings to lift  struts, fixing gas tank leak and installing new engine driven fuel pump and  electric fuel pump.  Does maintenance ever  end?

pilot4pay

Joined: 01 Jan 2007
Posts: 171
Location: Louisville, KY

Posted: Fri Feb 09, 2007 2:37 pm Post subject: VGs feathers on an 801

Aren’t VGs on the tail surfaces used for correcting control issues, not for changing stall speeds?  

Craig Smith  

         

  

From: owner-zenith-list-server(at)matronics.com [mailto:owner-zenith-list-server(at)matronics.com] On Behalf Of Keystone Engineering LLC

 Sent: Friday, February 09, 2007 2:36 PM

 To: zenith-list(at)matronics.com

 Subject: VGs feathers on an 801  

  

   

I finally got time to add 100 VGs to my tail to see if that makes a difference.  It did not seem to make a difference.  Here is a summary of my testing.  I only stalled the plane 3 or 4 times in each configuration.  The numbers should be within a mile an hr or two.  The winds have been light when I have done the testing.  I used GPS speeds.  To calculate air speeds at high altitudes I assumed the plane's speed would increase 3% per 1000' rise in altitude.    

   

Removed Leading Edge Slats off the CH 801  

   

Installed home made VGs 10% of chord and at a 45 degree angle  

Stall clean        55  

Stall dirty        43  

Cruise              I 108 MPH GPS 103 MPH   

Density altitude at 3000’        +500’   

Cruise at 4500’ Standard day                         115 MPH  

   

Installed feathers at 10% of chord at 12 degrees  

Stall clean        51  

Stall dirty        45  

Cruise  I 110 MPH      GPS 104 MPH  

Density Altitude at 3000’       +1500  

Cruise at 4500’ Standard day                         113 MPH  

   

Installed Feathers at 6% of chord at 12 degrees  

Stall clean        50  

Stall dirty        45  

Cruise not measured  

   

Installed Feathers at 6% of chord at 12 degrees  

Removed large VGs from tail installed 100 smaller home made VGs at a 15 degree angle  

Stall clean        50  

Stall dirty        45  

Cruise I 105 MPH       GPS 103  

Density altitude at 3000’        +1000’    

Cruise at 4500’ standard day              114 MPH  

    

Take off and landing distances are definitely longer.  They are a lot shorter than a Cessna but...  

    

   

    

If you factor the cruise to 6000' you would be 122 MPH.  The plane seems slipperier.  Not like a Bonanza or Mooney but more slippery that it was.    

    

   

    

Before VGs I used 50 as my final approach speed now I need to use 58 mph.    

    

   

    

Is loosing 8 mph on the bottom end worth gaining 10 mph on the top end?  

    

   

    

Bill Wilcox  

    

N801BW  

    

280 hrs  

    

Valdez, Ak  

    

Scratching head contemplating installing fairings to lift struts, fixing gas tank leak and installing new engine driven fuel pump and electric fuel pump.  Does maintenance ever end?  

  

       [quote][b]

_________________
Craig Smith
CH640 builder
SN: 0078

"Just think how stupid the average person is,
and then realize that half of them are even stupider!"
--George Carlin

n801bh(at)netzero.com
Guest

Posted: Fri Feb 09, 2007 4:20 pm Post subject: VGs feathers on an 801

115 mph in cruise out of a 801... WOW !!!!!!!!!!!!! you are the man, !!!!!!!!!!!  With one stout engine for sure... 

do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- Keystone Engineering LLC <keystone(at)gci.net> wrote:

 

I finally got time to add 100 VGs to my tail to see if that makes a difference.  It did not seem to make a difference.  Here is a summary of my testing.  I only stalled the plane 3 or 4 times in each configuration.  The numbers should be within a mile an hr or two.  The winds have been light when I have done the testing.  I used GPS speeds.  To calculate air speeds at high altitudes I assumed the plane's speed would increase 3% per 1000' rise in altitude.   

  

Removed Leading Edge Slats off the CH 801 

 <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> 

Installed home made VGs 10% of chord and at a 45 degree angle 

Stall clean            55 

Stall dirty            43 

Cruise             I 108 MPH GPS 103 MPH  

Density altitude at 3000’            +500’  

Cruise at 4500’ Standard day                115 MPH 

  

Installed feathers at 10% of chord at 12 degrees 

Stall clean            51 

Stall dirty            45 

Cruise I 110 MPH    GPS 104 MPH 

Density Altitude at 3000’            +1500 

Cruise at 4500’ Standard day                113 MPH 

  

Installed Feathers at 6% of chord at 12 degrees 

Stall clean            50 

Stall dirty            45 

Cruise not measured 

  

Installed Feathers at 6% of chord at 12 degrees 

Removed large VGs from tail installed 100 smaller home made VGs at a 15 degree angle 

Stall clean            50 

Stall dirty            45 

Cruise I 105 MPH    GPS 103 

Density altitude at 3000’             +1000’ Cruise at 4500’ standard day                 114 MPH

 Take off and landing distances are definitely longer.  They are a lot shorter than a Cessna but...

  

 If you factor the cruise to 6000' you would be 122 MPH.  The plane seems slipperier.  Not like a Bonanza or Mooney but more slippery that it was.  

  

 Before VGs I used 50 as my final approach speed now I need to use 58 mph.  

  

 Is loosing 8 mph on the bottom end worth gaining 10 mph on the top end?

  

 Bill Wilcox

 N801BW

 280 hrs

 Valdez, Ak

 Scratching head contemplating installing fairings to lift struts, fixing gas tank leak and installing new engine driven fuel pump and electric fuel pump.  Does maintenance ever end?

   [quote][b]

keystone(at)gci.net
Guest

Posted: Mon Feb 12, 2007 9:15 am Post subject: VGs feathers on an 801

Craig

  

 The suggestion was made that the tail was stalling  before the wing.  Adding more smaller VGs tested this  theory.

  

 You are correct the stall speed did not change but  I already had VGs on the tail.  The VGs on the tail give you more  elevator authority at very little cost.  For example adding VGs to the  "original" small tail for the 801 gives you more elevator authority than  changing to the larger tail.

  

 15 years ago everyone "knew" the only reason to use  VGs was to correct design mistakes.  Today they are used as a high lift  device and to direct vortexes when desired to reduce drag.  

  

  

 Bill Wilcox

 N801BW

281 hrs

Valdez, Ak

  

  

  

  

 Time: 02:37:33 PM PST US

From: "C Smith" <pilot4profit(at)sbcglobal.net (pilot4profit(at)sbcglobal.net)>

Subject:  RE: VGs feathers on an 801



Aren't VGs on the tail surfaces  used for correcting control issues, not for

changing stall  speeds?



Craig Smith

  _____  



From: owner-zenith-list-server(at)matronics.com (owner-zenith-list-server(at)matronics.com)

[mailto:owner-zenith-list-server(at)matronics.com]  On Behalf Of Keystone

Engineering LLC

Sent: Friday, February 09, 2007 2:36  PM

Subject: VGs feathers on an 801

I finally got time  to add 100 VGs to my tail to see if that makes a

difference.  It did not  seem to make a difference.  Here is a summary of my

testing.  I  only stalled the plane 3 or 4 times in each configuration.  The

numbers  should be within a mile an hr or two.  The winds have been light

when I  have done the testing.  I used GPS speeds.  To calculate air  speeds

at high altitudes I assumed the plane's speed would increase 3% per  1000'

rise in altitude.  

Removed Leading Edge Slats off the  CH 801

Installed home made VGs 10% of chord and at a 45 degree  angle



Stall clean         55



Stall dirty         43



Cruise               I 108 MPH GPS 103 MPH 



Density altitude at  3000'        +500' 



Cruise at 4500'  Standard  day                          115 MPH

Installed feathers at 10% of chord at 12 degrees



Stall  clean        51



Stall  dirty        45



Cruise I 110  MPH      GPS 104 MPH



Density Altitude at  3000'       +1500



Cruise at 4500' Standard  day                          113 MPH

Installed Feathers at 6% of chord at 12 degrees



Stall  clean        50



Stall  dirty        45



Cruise not  measured

Installed Feathers at 6% of chord at 12  degrees



Removed large VGs from tail installed 100 smaller home made VGs  at a 15

degree angle



Stall  clean        50



Stall  dirty        45



Cruise I 105  MPH       GPS 103



Density altitude at  3000'        +1000'



Cruise at 4500'  standard  day               114 MPH



Take off and landing distances are definitely longer.  They  are a lot

shorter than a Cessna but...

If you factor the cruise to  6000' you would be 122 MPH.  The plane seems

slipperier.  Not like  a Bonanza or Mooney but more slippery that it was.  

Before VGs  I used 50 as my final approach speed now I need to use 58 mph.   

Is loosing 8 mph on the bottom end worth gaining 10 mph on the top  end?

Bill Wilcox



N801BW



280 hrs



Valdez,  Ak



Scratching head contemplating installing fairings to lift struts,  fixing gas

tank leak and installing new engine driven fuel pump and electric  fuel pump.

Does maintenance ever end?

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