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VG's for AVID Flyer

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Posted

I finally got StolSpeed VG's installed on my wing 4 inches back and on the horizontal stab 4 inches from Gap.  The results are incredible.  Before installed my plane would start sinking drastically at 50 mph. With VG's it floats in nicely at 45.  I can slow fly at 35 to 38 and it feels stable.  The tail raises off the ground quicker.  With the 912 uls I can take off 3/4 throttle in 75 feet.  The torque is such that full throttle forces the plane to the left even with right rudder.  I have heard that installing vg's on the vertical stab eliminates this problem.  I am trying this next.  With the VG's the plane fells way less squirrely.  Definitely worth the investment.  If any of you are aware of different VG's that have an even better effect on the AVID let me know.  The slower the better landing backcountry.  The StolSpeed VG's seem very tiny compared to others and I wonder if the larger VG's create a stronger vortex over the wing to help lift.

Additionally I have seen some planes with what looks like wind dams at end of wing (using my terminology).  Do these do anything to improve slow flight?

 

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Posted

Could you post a few photos of the installed VG,s.      I had tested some many years ago on a low wing aircraft.   Regards Joe

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Posted

Sure.  ill take photos tonight.

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Posted

STOL or speed wing?

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Posted (edited)

STOL or speed wing?

its a stol HH wing.

 

When I repainted my wings last year I took the VGs off.  I can tell a big difference in them being gone and will be adding them back on when I get home.

 

Edited by akflyer

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Posted

I have not checked my stall speed yet.  Will be doing that this weekend.  My overall biggest problem before VG's was the sink rate on landing once the craft was below a certain speed. 

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Posted

Has anyone installed vg's on a speedwing ? Just wondering what it would do for me and the sink rate too .

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Posted

I agree it made me much more comfortable in landing as the wings quit the alternating dipping as my landing speed decreased. It is rock steady all the way down and dropped my stall about 3 mph. What I liked the best is the steadiness of the wings now as the speed decreased.:o

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Posted

It's good to hear some positive results. Most are pretty neutral on if they helped. 

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Posted

I had a couple of interesting conversations about VGs last week at OSH.  More Positive than Negative.  More work on placement than anything...

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Posted

I agree it made me much more comfortable in landing as the wings quit the alternating dipping as my landing speed decreased. It is rock steady all the way down and dropped my stall about 3 mph. What I liked the best is the steadiness of the wings now as the speed decreased.:o

Exactly!!! Now I feel much more comfortable pushing the speed envelope on landing because it feels solid.

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Posted

Ditto on all the positive changes above, huge improvement in my Mk IV on my 1000' strip with obstacles! Still need more practice and experimentation on the shedding altitude after 50' trees without splat.

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Posted

Sounds like my strip. Coming in to the south I have to slip hard over 20' power lines to land on 1000'. I give it a burst of throttle as I square up and flare just to cushion it about 5-10' off the ground and hit the brakes when I get down. Some times it cushions better than others lol. Some times I tail hook a little and sometimes I bounce enough to need a go around. It is a very slight down hill that direction with a barbed wire fence at the end. Its kind of hairy but I am learning each and every time I get in and out. Some day maybe all the learning will corispond with the environmental factors at the same time for more than an occasional greaser landing lol

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Posted (edited)

I have an old, but unused set of, I think 120 STOL VGs for wings and 80 for HS, in boxes with templates.  Haven't put them on the For Sale list yet, so if anyone wants them just check new prices and make me an offer and I need an address to send them to.   EDMO

Edited by EDMO

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Posted

Remember, when landing short strips throttle controls sink rate, elevator controls speed.  These planes will sink like a rock at 45 with the nose up carrying power.  Go to altitude and spend lots of time driving it around doing slow flight and become one with your plane at an altitude you can recover from.  1000' agl gives you time for a couple oh shits.  Once you are comfortable using half a stick of up and lots of power to hold level flight then you can practice from a higher altitude getting the max sink rate at say 45 mph.  Start off at 2k and have your landing at 1k  Get the feel, sight picture and tuned into the sound of the engine as you establish max sink at 45 using the elevator to control speed.  Figure out at what point you have to come in with the power to arrest the sink rate and "touch down" at 1K.  This gives you lots of time and altitude to get the nose down and fly out of your virtual runway in the sky.  If you have short places you are going into and out of you need HAVE to be completely comfortable and CONFIDENT with yourself and the plane.  Practicing this at altitude and getting the sights feel and sounds in your brain will go a very long way in keeping us from ready an accident report, sending flowers to your widow or helping you in quest to rebuild your plane after you recover from the learning experience.

I was very fortunate to have started off flying from day one with a crusty old bush pilot up here that knew what I would be doing so from day one it was slow flight, uncoordinated stalls, accelerated stalls and landing on the number each and every time.  The short and soft field "techniques" that are taught by most pavement pounding instructors do not go very far in the real world.  I can promise you that the soft field "technique" on a 152 or 172 that is practiced on a hard surface runway will not even come close to giving you a feel for what its like when the ground really is soft or when in high grass.  The additional drag etc will blow your mind how much slower it will actually accelerate and just how much more room it is going to take to get the bird in the air.  I had more than my share of oh shit moments when I first took a 152 off airport.  I ate up almost 3500' of soft runway trying to get the plane in the air.  Same thing on a hard gravel runway with 6" of fresh snow on it.  I used up most of the 5000' runway as I could not eek out that last 5 mph I needed to fly no matter what.  I just happened to hit the blown out part where a few runups had been done and was able to horse it off right there and stagger into the air.  Lots of lessons were learned very quickly by a cocky 20 yr old that first few years after the ink dried on the ticket and I thought I was a hot shit invincible bush pilot... Some didnt turn out as well as I had hoped :lol:  26 yrs later I am still learning new things or being reminded of old lessons long forgotten. 

Bottom line, get 100% comfortable with the absolute slowest flight you can achieve and maintain.  That extra 5-10 MPH your carrying going into a short strip is the difference between hitting the numbers and floating past them then either hitting the ditch after you jam on the brakes and go out of control or roll off the end and spend some time picking willows and alders out of your radiator and prop.

:BC:

 

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Posted

Thats good advice Ak. I trailered and practiced for months on the grass strip next tp the paved runway at the airport and measured out 1000' out of the 3000 available . I didn't even try my own strip until I was landing within that 1000' each and every time. My strip has trees down half of the east side so any kind of easterly wind will play a little with my sink rate when I drop below 20'. I have had times where I have a NE wind of 12 or so and come in as pretty as you please then out of nowhere you sink like a rock only 15' off the ground due to the lost wind. It is  great training and I get more comfortable each time. It took me a while to realize exactly where to plant my landings on 36 because there is a very slight dip over a 100' area that doesn't look like much but when you hit it at touch down and then hit the slight rise on the other side you get bounced enough to eat up alot of run way. Now I fly past the dip and can stop within 400' all day every day pretty much. The hairier side is 18 because I have to slip over power lines. The more experience you gain from every circumstance the better pilot you will become. You can read all day long but until you go out and do it over and over you just won't commit it to muscle memory. 

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Posted

Ok Ak, I re-read your post. Obviously you can't give advice on landing in a strip you have never seen and I understand that. My strip of land is 1093' with 20' power lines on the 1093' line and a barbed wire fence on the other.It is fairly open farm land with a big power line size tree on the NE end of runway and trees  about midfield to the south end on the East side of the runway (plays with the sink rate moving between the open area to the treed area when any easterly wind is there.) Essentially 800+ usable runway coming in from the north or taking off toward the north. I have practiced the slow flight you speak of but not sinking in a nose high attitude the way the STOL guys do it in OSH or Valdez. I come in rather flat with a little bit of power about 15' over the power lines shooting for 60 to account for any drop in wind gusts. As I come over the power lines I chop power and I kick hard right and drop the left wing. I flare and straighten at about 5-10' and add a burst of power to stop decent and cushion the sink. From power lines to touch down eats up 200-300 feet leaving me 700+ of very slight down hill to brake and stop. I can see coming in at 45 nose high would reduce my role out some but not sure I would be able to judge coming down over the power lines in that attitude to be able to get it down and stopped like that.  My thinking is that would be better suited for coming across a river bed clear of obsticles and holding a lot of power to get you to touch down on a stream bed. How do others land short coming in over obsticles? Always looking for new ways of doing things and I would definately go back to the airport and try in the open first.

Mark

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Posted

my way you can come in over the powerlines at a higher altitude and fall out of the sky without picking up any extra speed you will then have to bleed off.  The down side is if you loose power your going to be in the trees.  Always have that hand on the throttle and be ready to go wide open if needed. 

Landing a short strip with obstacles is landing a short strip with obstacles.  Doesn't really matter if its powerlines or 100' tall trees, you have to clear the obstacle and still get it stopped in the runway you have.  People tend to use the runway they have available.  Instead of marking out 1000', mark out 500'.  If a strip is 100' wide and 8000' long people will use the whole damn thing from time to time.  If its 20' wide and 400' long they will somehow be able to keep it within those confines.  Lots of the places I land is much less than 20' wide and at the end of the 400' serious consequences, not just a little scratched paint.

:BC:

 

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Posted

Good to know I will start practicing that.

Thanks Mark

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Posted

I finally got StolSpeed VG's installed on my wing 4 inches back and on the horizontal stab 4 inches from Gap.  The results are incredible.  Before installed my plane would start sinking drastically at 50 mph. With VG's it floats in nicely at 45.  I can slow fly at 35 to 38 and it feels stable.  The tail raises off the ground quicker.  With the 912 uls I can take off 3/4 throttle in 75 feet.  The torque is such that full throttle forces the plane to the left even with right rudder.  I have heard that installing vg's on the vertical stab eliminates this problem.  I am trying this next.  With the VG's the plane fells way less squirrely.  Definitely worth the investment.  If any of you are aware of different VG's that have an even better effect on the AVID let me know.  The slower the better landing backcountry.  The StolSpeed VG's seem very tiny compared to others and I wonder if the larger VG's create a stronger vortex over the wing to help lift.

Additionally I have seen some planes with what looks like wind dams at end of wing (using my terminology).  Do these do anything to improve slow flight?

 

 

 I have a set of Stolspeed VG's and was wondering if you could share your placement information with me?

 

 

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Posted (edited)

I finally got StolSpeed VG's installed on my wing 4 inches back and on the horizontal stab 4 inches from Gap.  The results are incredible.  Before installed my plane would start sinking drastically at 50 mph. With VG's it floats in nicely at 45.  I can slow fly at 35 to 38 and it feels stable.  The tail raises off the ground quicker.  With the 912 uls I can take off 3/4 throttle in 75 feet.  The torque is such that full throttle forces the plane to the left even with right rudder.  I have heard that installing vg's on the vertical stab eliminates this problem.  I am trying this next.  With the VG's the plane fells way less squirrely.  Definitely worth the investment.  If any of you are aware of different VG's that have an even better effect on the AVID let me know.  The slower the better landing backcountry.  The StolSpeed VG's seem very tiny compared to others and I wonder if the larger VG's create a stronger vortex over the wing to help lift.

Additionally I have seen some planes with what looks like wind dams at end of wing (using my terminology).  Do these do anything to improve slow flight?

 

 

 

 I have a set of Stolspeed VG's and was wondering if you could share your placement information with me?

 

 

Wind dams, commonly called "fences" are sometimes installed about 3/4 of the way to the tip of the wing, causing a blockage of the under-flow and a vortex to form where it cant get over the top of the wind, supposedly reducing drag - My design book says that "flat plates on the end of the wingtip would have to be chord height to be effective", but don't hold me to that because I am sure that more research has been done since the book was written 50 years ago.  Hoerner or other modern squared tips angled up from the bottom are supposed to increase lift and reduce drag a lot better than rounded tips.  Just look at the results on the Short Wing Piper site, and I copied some results from there and posted it somewhere on this site comparing "Droop tips and Others", I think.  Winglets are the proven maximum tip design, I guess, They add virtual wing span without making the wings longer - just look at all modern passenger planes.  This still takes some good engineering and testing to be effective.  My 2c worth.  EDMO

Edited by EDMO

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Posted

I put mine on this time 3.25" back from the leading edge.  That is, the front of the VG starts at 3.25" back.  I went with 60mm spacing the whole wing.  Last time I went ti the 4.1" at the 10% recommended and feel they do more good at around 7%.  I have the VGs under the tail as well and they help.  Using clear tape to seal the elevator gap is a BIG help and very noticeable. 

:BC:

 

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Posted

Thank you very. I will work on getting them added this weekend. Would like more detail on the clear tape gap seal too. What did you use and how did you apply it. I assume it goes on the bottom.

  :BC:

 

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Posted

Regular clear packing tape on the top and bottom . make sure you deflect the stab each way while installing so it can attach in the middle . It's the one thing I've been meaning to do but keep forgetting.

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Posted

Clear gorilla tape this time.  Last time I used the thick clear tape that snow boarders use on the top of the boards, that lasted about 5 yrs.  Getting the remnants off was a pain but with a heat gun set on low it was not too bad of a job.  If you are keeping your bird in a hangar it should last a long time!  I just put the tape over the gap on the top side with the elevator in the full down position.

 

:BC:

 

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