Vortex Generators

[J5Ron]

I know it has been discussed...but saw an add in Barnstormers about VG's built by a guy in Idaho...the VG Guy... He sells a complete set...with install plans for $95.00 .... His web site is www.landshorter.com
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Does anyone know of these being used on a cub( his VG's that is) ?

They are not STC'ed....so his web site claims a 337 and a field approval will be needed...however...is this something that the feds will field approve...

For 95 buck I would like to try them...but if I can't make them legal...I won't mess with it...

Ron

[cubunltd]

In todays world, I doubt you could get these approved very easily. they affect the flight characteristics of the aircraft and would require a DER or FAA engineer to approve.
cubsunlimited@verizon.net

[Tom Jones]

According to his web site, you need to do your own flight testing to determine "optimum placement". Lots and lots of work and time, presuming you have the skills and patience... probably more so than you think.

Spend the money for certified VG's. I have Micro Aerodynamics VG's and really like them. Beautifully done kit with templates, no guessing and no flight testing.

Better yet, no arguments from the Feds. File the 337 for the STC and you're done.

[Rookie]

Tom is right; the Micro Dynamics kit is really good. The instructions and templates make it easy to do the installation nice. I did it on my (certified) airplane, hired an IA to check my work and handle the paperwork, and couldn't be happier with the results.

If you really want experimental double plus secret technology, you could try talking to Jerry Burr. He did the flight testing for the Cub Micro Dynamics kit, and is working on some incremental enhancements that I've seen on his highly modified J3.

Also, I don't like the idea of the plexiglas that's being used in this kit without paperwork. The glue provided in the MD kit is strong enough so that a good whack on a VG during washing or something like that would probably result in bending of a VG. If they were made of plexiglas, they'd probably snap off instead. The STC includes a restriction that you can't fly if you're missing more than five VGs (they also give you a nice field kit to make repairs if needed, never heard of anyone needing to though).

If you don't like the idea of permanent installation, I know of a MD installation using double sticky tape that's holding up fine. MD has super support available on the phone too. (I didn't need any, the kit was very complete, but talking to them about painting was very helpful.)

The only thing I did a little different that what's written up in the kit, is when I'd completed placing VGs in a section, and before the glue had entirely set up, I went ahead and removed the contact paper template, using great care to not disturb the placement of the VGs, but also taking excess still soft glue away at the same time. I recommend being very careful to place the VG exactly in the center of the hole, the one VG I missed on just a tiny bit ended up with a nearly invisible sliver of (green) template contact paper in the glue bead that I wasn't able to trim out without undue risk to the fabric (only willing to cut so far with the provided exacto knife for clean up).

-->Aaron

[SJ]

I gotta agree, the templates and stuff in the Micro VG kit are worth a heck of a lot. Maybe this other guy has them too, and if you are experimental, go for it, but getting things field approved that "effect flight characteristics" is gonna cost a LOT more than the $675 for a set of Micro's...

BTW, nothing wrong with the BRL's either. Both do a LOT to improve the safety of the aircraft, although there are some minor differences.

sj

[Rick Papp]

I really like my micros, ooooooh sooooo sloooow, with good authority. Rick.

[storm_pilot]

How much will the VGs slow you down in cruise?

[Rick Papp]

borer, micros, bigger tires,150hp,...........@90mph at 2450 on a good day Rick

[Jon B.]

Does any of you know of a Champ with VGs? I intend to use the bottom end of the flight envelope much more than the top end of it, and would like to do so in a safer manner.

One fellow says that Champs with VGs can't be spun, another says his will spin nicely. Did not! Did too!. What's a guy to do? Call the manufacturer, I guess.

Jim Drometer, in Belle Plaine, Minnesota sells VGs and says his price is better than the $660 that Aircraft Spruce asks; anyone buy from him? He didn't say what he gets, only that he can do better.

Jon

[SJ]

It will be a few more weeks until his new wings are in, but my buddy is going to install VG's on his 7ECA. I am real interested to see how it flies after that. The plan is to fly it a little bit, then put them on and see what happens!

sj

[cubunltd]

Stormpilot, VG's have very little affect on cruise speed. they enhance aileron control in all regimes. but really excell in slow flight and stalls. I have installed them on at least 6 supercubs and 2 PA12's with dramatic results. I use BLR's and have flown them a lot. I have several buddies that have the Micro's and they claim similar results. I have a supercub in the shop now that has Micro's on it and will fly it in a couple of weeks. Curious as to what the differences really are. Typically with 150 hp and 26' tires, 8241 Borer prop cruise is 95 at 2500 rpm.
cubsunlimited@verizon.net.

[Rookie]

When considering purchasing a flight altering device like VGs, I'd recommend not just looking at the bottom line price, but also taking into account the service that comes with the purchase. For example, I wouldn't pay $660 to Aircraft Spruce for a kit, but I would pay $695 directly to Micro AeroDynamics, Inc. because I know from experience that if I have any questions, I can get them answered directly from the source.

You can find Micro AeroDynamics on the web here:
http://www.microaero.com/

-->Aaron

[cubscout]

Re: VG's on Champ, the closest I know of is a Scout at Boulder Intergalactic. The owner claims they help the low end a lot, and give him some margin getting in-and-out of short strips, and yes, he's found some cool spots in the Rocky Mountain area. If you're interested, I could probably dig up contact information, but not 'til next week.

There's a chat group on Yahoo called Citabria Pilots or somesuch, but spanning 7AC's to 8GCBC's. Someone there has probably done something like this.

Good luck on your project. Cubscout

[mvivion]

The other advantage to speaking direct with the manufacturer (and stc holder) is that they (he) may give you a deal, especially if you ask for it.

Tell him your'e a member of all sorts of organizations, including of course, a regular lister at Supercub.org, and maybe he'll squeak you a few bucks off.

MTV

[JMBreitinger]

Does any of you know of a Champ with VGs? I intend to use the bottom end of the flight envelope much more than the top end of it, and would like to do so in a safer manner.

One fellow says that Champs with VGs can't be spun, another says his will spin nicely. Did not! Did too!. What's a guy to do? Call the manufacturer, I guess.

Jim Drometer, in Belle Plaine, Minnesota sells VGs and says his price is better than the $660 that Aircraft Spruce asks; anyone buy from him? He didn't say what he gets, only that he can do better.

Jon

I flew a new Citabria with VGs. They had about the same affect as on my Super Cub.

Jim installed the Micro VGs on my Cub. As I recall, they were in the neighborhood of $900 installed -- about a day's labor. They made a huge difference.

Jim says that it makes it a lot harder to spin a Cub but that you can do it.

[Jerry Burr]

Hi Guys. I will sell you Micros for $660.00. And answer your questions, on the Super Cub / J-3 only. Next day shipping. Except on week-ends. P.M. me. Jerry.

[PA12driver]

Hey Jerry, I need one more VG, (just kidding) will you deliver to CW Island? I will pour the coffee!!

Best bang for the buck on any cub wing are the VG's, both BL and MD work well, however the strake is in the way on the BL's and unless (in my opinion) you build the mount base for it before covering you are taking the chance of bending the fuselage sooner or later.

Rookie, you are absolutely right about "NOT" leaving the template in place till the glue dries. I recomend placing 2 ahead, and by then go back and pull the first one, also more is not better with the glue!

Tim

[aktango58]

Champ and VG's

YES! they worked well. Put micros on my 7AC, has a 90 hp. Was the difference of taking off at 44, or off well before 40 (ias on my airspeed). Made the thing feel solid on approach. Was so impressed, that I put them on the 12 I often fly at my expence, even though it is not my plane.

The champ is for sale if you want it, with vgs cleavlands and 90 hp!

George

[kxo300]

Hi Guys. I will sell you Micros for $660.00. And answer your questions, on the Super Cub / J-3 only. Next day shipping. Except on week-ends. P.M. me. Jerry.

Hi Jerry

I see at the Micro AeroDynamics website the "New, Improved" VG's for the 12 and 18. What did they do for the improved version? Different placement or the size? I would like to know before ordering.

I'm flying floats on my 12 and the aileron effectiveness really "sucks". I've found it really hard to pull one float off early to help with a glassy water take off.

I built a Kitfox 4 and had it on floats and was accused of slaloming with it!

Thanks - Gary

[Jerry Burr]

Hi Gary. The V.G.'s on the wings were changed to the large type. And they were added to the bottom of the Horizontal Stab. The ones on the horizontal are the only ones that you will probably (notice) the difference in flight. Jerry.

[diggler]

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[Jerry Burr]

Hi Diggler. That is correct and yes. Jerry.

[S2D]

The champ is for sale if you want it, with vgs cleavlands and 90 hp!

George

Whats the history on the engine? TT -- SMOH --and how long ago? is it a -8?

[Crash]

Hi Diggler. That is correct and yes. Jerry.

If size makes no difference then why did they change them? Crash

[tempdoug]

another straight forward question id like to add to yours, crash, is under what conditions would the blr tail strake show more slow flight performance and what conditions would the horizontal vgs shine, also some put them on the vertical fin, any answers?

[diggler]

[delete

[JimC]

To work properly, vg's should extend up through the boundary layer by about 20% of their height. The thickness of the boundary layer increases with increasing aoa and the seperation point moves further forward. Consequently, for any given chord location, taller vg's will continue to function to a greater aoa before being submerged and becoming ineffective. On the other hand, the taller vg's cause a greater increase in skin friction drag, so in order to minimise that contribution to drag, you can (if so desired) either place taller vg's further aft, or smaller vg's further forward. It's all a compromise, as is just about everything involving flight. You can also place taller vg's further forward for maximum contribution to stall reduction if you are willing to take the hit on skin friction. Note that the skin friction increase may in some circumstances be offset by a reduction in form drag.
Hope this helps.
All the best,
JimC

[Jerry Burr]

AAAND the winner is Diggler. Actually I have 3 subjects so will go off topic first. The gadgets that are available to us today are no less than amazing. I was given a runners GPS. It velcros to your wrist just like a Dick Tracy radio. It gives as much info or more than the one in my airplane. It will even lead you home if you get lost. Might be cool for hunters. Today I ran 19.1 miles in 3:29. Burned 2353 calories and that boils down to 33208 steps. As I sit here by the fire with the puter on my lap, I can't help but wonder, what's next.
V.G.'s. I believe that the BLR V.G.'s have to be of the large style. As J.C. pointed out, the farther back on the wing you go the fatter the boundary layer becomes. Up at 4% of the chord Micro works just as well with either large or small.
As for the strake (delta fin) or the V.G.'s on the bottom rear of the stabilizer, this is what I know so far. I have started tests on the famous Moose Stall. But the weather has not been in my favor. And I am using my Cub for the initial tests, until I can find a stock one. I have cameras on the top of both wings and also under the stab/elevators, both sides. This is filmed on a 4 part screen so I can watch everything at one time. The first thing that was a surprise is that the entire wing stalls and stays stalled in a spin. The outside wing is not flying while the inside wing is stalled. I think SD2 best said it when he likened it to a somewhat vertical snap roll. With the bottom stab V.G.'s the elevator is flying at all times. It is never stalled even in the full up position. The upwind stab/elev has a slight angle to the tufts on the upwind side of the fuse during the spin, but both sides are flying. Someone said that one elev stalls and that's what tips them over. I don't know because mine will not do the moose stall. So the entry will have to be tested later with a stock Cub. I taped a delta fin on both sides of the fuse to duplicate the (Strake) and there was no change on the flow pattern under the stab/elevators. There may well have been a change on the top side, I don't know. There is always plenty elevator to get the nose to go down, so the top side doesn't interest me. It was slower to get a stall break when pushing against the strakes. This may be a considered a safety trait, in that it is harder to unintentionally stall a Cub. I prefer the ability to stall when and where I want to get either a large sink rate or a good 3 point landing.
The V.G.'s on the vertical are very powerful. I put them on the vertical, so as to get more rudder power to assist the ailerons at very low speed. Before them I could rarely spin to the right, as the right rudder pedal was already against the firewall. With the V.G.'s I can easily spin either direction. The down side is that at cruise speed in moderate turbulence the Cub turns in to a Tri-Pacer or Bonanza. It picks up the Bonanza wiggle. It's not bad if you have a mountain to look at or a river to follow. But in the central states when trying to follow the compass, it's all but impossible.
I hope this answers more questions than it creates. I'll share the new information as it becomes available. Hopefully winter will bring some still clear air. Jerry.

[Marc Olson]

Are the VG on the vertical stab still in development?

What ever happened to the VGs on the underside of the wing that you were working on last summer?

Marc

[diggler]

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[aceherks]

Diggler: Obviously the BLRs must be twice as good?

[Jerry Burr]

Hi Mark. Both the V.G.'s on the vertical and on the underside of the wings were done on (one time only's). Neither were considered appropriate for a multiple STC. Diggler, as long as the V.G. that you are installing fit's the hole in the template, you are in. Jerry.