Many thanks for your efforts on this project guys - your research is heavily influencing my decision to likely steer away from selecting the STi wing with my S7 kit: If I can achieve a level of STOL performance close to that of the STi wing with the regular Super Sport wing and VG's - especially as I'll mostly be flying close to sea level - well that'll do me nicely. Do you know of any one else who's been able to verify your results on another Kitfox S7 SS? When I visited Kitfox last October, I mentioned this video to John McBean and he, (much like the UK LAA's Chief Engineer who I also mentioned it to earlier last year) sounded quietly enthusiastic about your results. John suggested someone in the US *had* achieved similar results, but I don't recall who or where they're based. FWIW, I don't think it was Alex Di Sessa; I see he mounted his VG's even further forward on RedFox in this video: ruclips.net/video/XPC8egjwjY0/видео.html - which I can imagine is less effective at higher AoA. Btw, It would be great if you could add the VG manufacturer names to the info section too please. :) And the $64M question: who did kill off your 'VG's can kill you' vlog? Google search is like it never existed - except on three Russian spam sites. Keep up the great research! :)
Hi Hamish! First of all that's for the amazing feedback, we really appreciate it! Sorry for the VERY late reply! But we are in the process of doing this on another KitFox Ss7 here in South Africa, we will most probably make a follow up video - don't know about anybody else who has done it according to our method though. For the VGs we used Pacific North West's. And to answer the $Mil question, we decided not to complete it because we covered most of the topics in this video... It's just important to do your research and not just spit and paste a bunch of things on your aircraft because someone said to - because it can make a huge difference in the handling of your aircraft!
@@About2Stall No worries at all - we're all busy :) Thanks for the VG manufacturer info. Here's a link to Pacific North West for anyone else interested: www.pnwaero.com/kitfox Looking forward to the follow up video. Many thanks again for all your efforts guys! :)
This was a great video & highlights how important it is NOT to mess around with the design of your aircraft unless you are experienced & fully understand the principles. You guys nailed it, but given that I am a low hours pilot I don’t think I’ll go out & stick a VG kit on my aircraft just yet!
Evidence based data backed up by well-done testing of their hypothesis to prove the concept. Will definitely change the position of my VG's on my Highlander wing to rib based and add the roof. Nice to know the gap seal needn't be fancy but can be 3M clear tape or duct tape if appearance is of no issue. No airfoil is left unattended makes total sense to me. Great work and please keep going with the top gas cap work as I am at a loss on how to attach that to the wing.
Thanks for the time you took doing the research and testing on the vortex generators. I have a ss7 kit coming this week and am gathering all the information I can.
Great video and report. Thanks. For my Gap seal on my Kitfox 4 elevator I used clear Gorilla Tape (brand name). Does the job and doesn't stick out like a sore thumb. Gap seal was a huge improvement. I have not done the vortex generators yet but planning to. Thanks for some great info!
Hi Teddy! We have a nice permanent solution that we will release very soon. Main objective to be simple and as you mentioned... not stand out! Thanks for the feedback!
My tail design w/scoop that Ferrari scoop lets air from right travel thru tail & same the other way to keep balanced flight. The rudder needs 3 deg of free flutter per side, & u put vortex on the front of the tail not sticking out but serrated cutting lacing the air along the tail, locking it in. & it generates less shoot serrated thinner tail drag while more control.
Very nice results, I found the most interesting part was about the roof. I had a loose plane to actually raise my turtle deck and aft portion of the plane so that it was a straight line from where your VGs are to the tail. After reading some NACA documentation, that angle should be 7 deg or less and I think the way it drops down, it's closer to 11deg. I have a composite leading edge that goes make 200mm from the leading edge so I don't have the fabric dipping between the fabric of the ribs. I wonder if moving my VG's between the ribs will still make a difference... I think my VGs are currently 50mm back. I am going to tuft my plane very soon so I should play around with the wing tanks distance as well. Thanks for taking the time to do this. I have a lot of mods for the Kitfox that I want to do. The one that I haven't come up with a solution yet is to get rid of the gap between the horizontal stabilizer and the vert stab and have a root fairing while still being able to move it..
Hi Josh, Thanks for the feedback. The roof was indeed very interesting and we will be installing a wing fence between the roof and the wing in the next week to try and delay the stall a bit more. We also flattened those little corners that stands up to fold the wing under the roof. Didn’t make a difference. We are working on a very effective permanent DIY solution for the gap at the horizontal stabilizer, we tested it on a mock-up setup and it looks promising. Once we are happy we will be sure to post a video. And the next part is just to tease you :P… but we have a very simple but radical mod that we will be implementing in the next 2 weeks that should give us another 2kt off the stall. The best thing about the VGs the cruise didn’t change… Keep well! Fly Safe!
Great video guys, very informative and the tufting really helps to show the differences. Did you end up keeping the stall fence? Did you try any other positions or more than one for it?
Hi John, thanks for the feedback. With the tuffs we could clearly see the line of the stall and how it pulls at the rest of the unstalled wing. After installing the fence, the stall was contained to the stalled area. We are busy installing a second fence between the roof and wing.
Hi Texas STOL, There were two improvements. Firstly - At some stage before adding gap seal we could not stall her anymore because we lost elevator authority. She would pop up like a balloon at the tail - The weirdest feeling - By adding the VGs to the roof this happened at a lower speed and not such a BIG pop. Secondly - this actually makes your stall speed lower. The first air to detach from the aircraft is the roof. And if that goes it starts "pulling" the air on the wing, basically inducing the stall. So by delaying this, we delayed the stall. We will be installing a wing fence between the roof and wing to improve this even more... Hope this answers your question.
Guys, this is an awesome well researched video. I am going to do the same to my Kitfox 7SS. I have few questions: 1. Did you do both sides of the rudder? Elevator? 2. Would you be willing to share the drawing of your wing fence? Many thanks for the detailed information and research!
Well done, if you get the stall only a little slower, you will be able to tell the passengers that they can climb out and start walking on final approach. Regards
Great informative video. Have you thought about a wing cuff from the wing tip to either half way down the wing or to the wing fence ( similar to the Icon A5 ) and vortex generators from the wing fence to wing fence. Will be interesting to see how it effects stall and STOL characteristics.
Hi Regon, Yes we did look at a wing cuff, we are busy getting a slat. The problem with adding a wing cuff from wing tip to the half of the wing is that it will only improve the outside which is already working great. The stall will still happen at the same speed on the inside of the wing(our problem area). Before looking at any improvements on the outside, we need to improve the inside. So putting a slat the entire length sounds like a great plan 😀
Great video! A lot of great testing and information here. I am curious if you know whether or not the same spacings and placement would work on a Just aircraft Highlander wing? Also. Did you ever come up with a solution for the fuel cap? Maybe a fuel cap fairing in front?
The only question I have is at the end 10:00+ landing, shouldnt the root stall before the tips so that outboard aileron control is maintained. Yes I realize it is flapperons. But a full span simultaneous stall is unsafe. EXCELLENT VIDEO 👍👍👍
Thanks! You are correct, that's exactly why the VGs on the root side of the wing fence is further back than the other. This allows the Root to still Stall first while also improving the Stall Speed of the inner wing relative to what it was... Hope this makes sense?
Thanks for making this awesome video. Do you know if the wing on a series 5 Kitfox is the same as the 7?Would it be possible for you to make the cad file you used for the stall fence available for download? Also, it looked like you used a different VG on the roof section? Also, I used 3M blender tape for my gap seal and it works great, just need to put some Vaseline on the hinges so it doesn’t stick to them.
Hi Rjh! We really studied every test flight to see if we are improving. And there was many of them! Once you stop worrying about airspeed and actually look at what the air is doing... Thanks for the support!
Hi Leslie, We first shaped it out of wood, until we had a nice fit. The position where we saw we needed to install fence was inline with one of the flapperon attachment arms, we hooked it over the leading edge and bolted at the flapperon arm. Doesn't move much but to be sure we added 3 90degree 1cm feet. They are attached with double sided tape. The final one was made out of aluminum and powder-coated. Hope this help?
I have a Aerocomp MerlinGT. It is very similar to the Kitfox , I didn’t see what the final spacing is between the spars. I will be putting VG’s on mine really soon. Would like all this info , but I don’t see it.
What a great video…. I am the first customer to have the new Rans S21 Outbound flying. I was hoping for A little slower stall speed but it always seems to come in at 45 mph, so I’m getting ready to install my VG‘s based on manufacturers (STOL Speed) suggestion a placement starting with the leading edge of the VG at 7% but they are using 90 mm spacing on the inbound portion of the wing and at the tips they use a 30 mm spacing I am wondering if going to a tighter spacing would have better results? If you have any thoughts on that it would be greatly appreciated also I believe after watching your video I’m going to install them across the top of the fuselage on my window area. Thanks again for a great video, your results are quite amazing.
Hi Tailwheel Flyer, Thanks for the feedback! ***First a word of caution*** It is extremely important that the inner section of the wing stall first. If it is not the case this will result in a stall spin scenario. Only after many visual tests with the tuffs did we moved them closer at small increments and each time recorded on video the stall order. Making sure that the inner wing stalls first. We continued doing this until we could not move them any closer. And still saw the inner wing stalled first. This will differ from one wing design to the next. The kitfox wing is just so well designed to stall in the inner section. This may not be the case with your wing. The recommended layout is usually safe without having to test. As soon as you deviate from it. You will have to test in very small increments. And before changing anything, really get to know your aircraft - it usually takes about 200 hours or 1000 landings 😊 Also the location of our wing fence, was with the help of visual results from the tuffs, you could clearly see the line between the inner and outer wing during the stall. If you have any questions, we will be glad to help. Safety first!
Hey Nic! Will send you the drawing as soon as we adapt it for the KitFox 4 Fly safe, keep up the lekke movies! For those not familiar with Nic... he is one of our vlogging friends in SA... Check out his channel: m.ruclips.net/user/NicHolmes
Seems like a test that no one is doing is comparative touchdown distance from a 50' obstacle. Would love to see how reducing stall affects this distance.
Reduce stall will definitely reduce that distance. But your result on a landing will be more dependent on the skill of the pilot and changing anything takes a few hundred landings to perfect the landing. Think thats why its never in the test video. But if you think about it: a lower approach speed and keeping the same rate of decent will result in a steeper angle of approach and will result in a shorter touchdown distance. Thanks for the feedback. We appreciate the support!
So instead of adding aluminum drag BS the better way is serrated leading edge shoots making adding on new sheet metal to the both sides right & left if flying faster than 200mph, slower only 1 side.
Hi Cameron! We used high quality double sided tape (for easy removal while testing). We do however recommend that you go for a more permanent solution once your placement is final.
@@About2Stall yeah, here in the Cape vg's are a pain to land in a screaming south easter, just as you are finally settled it wants to jump in the air again.
I would love to have a constant 30kt wind.... we would be able to land in slow-mo! Think this sounds like a movie! "Fighting the "Doctor" to land" -For those not in the know: the "Doctor" is what the locals call the famously strong south easterly wind.
would you recommend any major changes to a kitfox model 3 wing? I'm not really familiar with the model 7 wing but the 3 has a fair bit of undercamber. Otherwise I'm not sure what the differences are exactly.
Hi Eldon, Thanks for the support! It will be reckless of me to apply the knowledge that I have of the SS7 directly to the kitfox 3. If there is one thing we learned is that small changes makes a big difference. My main concern is the difference in the inner wing. The 7 was almost over designed to stall at the root. So VGs had very little effect on this section. So a tight spacing worked. But on other wings not so overly designed to stall at the root doing the same placement will invert the stall. Having deadly results. I know there is many kitfox 3 out there so I will definitely do some research to assist. Will revert in due time. Keep well! Fly Safe!
I’d love to know this information about my plane. How did you attach the VG’s I order to remove them without any damage? I fly a 1956 172 with an Alaska bush tailwheel conversion, and Horton stol. VG’s are next on My list. Great video. Thanks.
Thanks for the great feedback! Before I tell you how we managed to remove them so many times… I have to caution you!!! Just as awesome as VGs are… they can change your stall characteristics in such a way that you can lose control on a routine stall exercise. We are busy editing our video “VGs can kill you” where we talk about the dangers of installing VGs incorrectly. Stalling your aircraft is never a good idea! For testing purposes I will use aluminium VGs for the simple reason, in the beginning we removed the old 3M double sided silicon based tape by hand. After round 3 I had blisters. So I hired someone full time to do it. We did it more than 50 times. We tried every position you an think off. Then when I had to do it again I tested every possible way to remove it. Tried cooking them, tried ultrasonic cleaner… And then finally, put them in paraffin overnight and the silicon falls of in the morning. Necessity is the mother of all invention. So use the aluminium VGs with 3M 1mm double-sided sheets. We used a gelatine to cut then to size. To remove them make sure you leave the aircraft in the sun for a few minutes. If you try this while it is cold, it will take some paint with it. We then used a twisting motion to remove them, not a pulling motion. You will lose paint if you pull them off. We found that a VG pair works much better than singles. It is when you place them to close to objects or changes in the wing that a VG can actually increase the separation of air. We found to keep at least 30-40mm from all changes in the wing. This counts for pair and singles. The best way to test is to install tuffs and record a stall in all 3 configurations so you can understand how your wing works. Then use the recommended installation by the manufacturer. Again do stalls in all three configurations. Look and study the footage make sure that the placement they recommend keeps the stall order and pattern the same. Even if you get slower stall speed and the stall pattern is not the same or better… TAKE THEM OFF. It is not worth the slower speed. After ever small change we did, no matter how small(6 months), we recorded a test flight with a very fast stall(release back pressure at first signs of stall) to make sure we are moving in the right direction. We have so much footage of a kitfox stalling, I think we will put it in a stall compilation. I hope I didn’t bore you with too much info… I will go read up on your aircraft to see what has been done with VGs. Keep well! Be Safe!
I am building a kitfox ss7 standard wing with the Laker leading edge, would you install the pacific nw aero vg's in the same way you are showing ? Thanks so much , billy
Hi Billy! It's difficult to say how the leading edge will affect the performance and installation of the VGs. But I think it should work just fine. We used the ribs in the wing as a reference for placing the VG pair, as mentioned in the video. If you can still reference the ribs in that same way for the install I think it should work great, mabe even a bit better given the surface wil be "smooth" compared to ours. Would love to hear your feedback, if you do decide to go with our Installation
@@About2Stall Thank you very much for the reply. I agree with you that the Laker Leading edge should be a good system for your design and study of the VG's. I am the oddball ..... going with the 160 HP Lyc., whirlwind prop., so I am 100 lbs., heavier right out of the gate, and will share my data with you when I have some. I would expect about 3 months from now. and while I am writing this, a question for you ..... have you developed a elevator gap seal yet ? I Thank you and your team for this extensive flight data you are sharing with all of us , you guys are the BEST !! billy
Absolute pleasure! Yeah, that is a bit different than the norm... Really curious what your performance numbers will be. We have a prototype of the new Gap seal, but we're still in the testing fase. Will keep you updated once we have it ready. It's our absolute pleasure sharing our research. That's how we all contribute to GA!
@@About2Stall Hello again, I received my airworthiness Certificate last week and ready to haul my Kitfox to the airport. I am asking if you have completed your gap seal project yet? I would love to use them since I copied your VG layout. Keep the fun alive !!! Billy
Dankie vir die terugvoer AJ! Mens weet nooit of mense daarvan sal hou nie - So ons waardeer julle ondersteuning!! Ons sal definitief só iets moet doen! - Hou ons Sosiale Media dip, dan reël ons dalk só iets!
Wow ... You guys went all out on vortex gen research for this airframe .. more so than any other group or individual worldwide to my knowledge ... At the time Im making this comment you have 3,845 views .. rest assured this will surpass 100,000 , likely before the year is out . You have no idea the demand for this raw data from backcountry pilots worldwide but you soon will
@@About2Stall Helpful !! It is unprecedented what you have done ... This reads like a research paper for ones PHD ... Its not just another flying / entertainment video ... which don't get me wrong we dang near live for those ... This is something else .. something that takes extraordinary time and effort as you mentioned ... and the results are of great value ... Its like your giving away an intellectual property ...and we cant believe its free .... Helpful !! Ya thats an understatement ... My plane is getting this South African treatment
If we had to go into everything there is about aviation in one video I am sure it will be way to long... but please feel free to add your expertise, that way we all help grow GA! We are planning a follow up in the future, will definitely explore that aswell!
@@About2Stall ready to cover my SS7 wings , great videos, Thank You for all the info.... Could I get a sketch or print on placement for those 236 VG's. Cell 360-914-0014 Washington State, Would be very glad to pay for them, You have done a tremendous amount of study and investment to the Kitfox world of aviation. If I could pay for some of your work ,I would gladly do it !! cheers, Mark
the left side wing gets no vortex generators for these small craft but gets serrated leading edge shoots. It is opposite way to make vortex only 1 is cut shoot out & other is cheap shit but Works add-on. The cut-out is less after market new design but is better way less drag to do the same thing. 1 wing no wing or above 200mph both wings but ony 2/3rds of the wing.
the tail on this high wing, bad design, needs a snailing strong Kevlar fabric over that makes plan 3 or 4 ft+ longer. The fabric over wire shock lets some air in & adds no real weight & very little drag but great free flowing control, needing no imput.
your making a Ferrari scoop only by DRAG adding on vs new design serration so air is cleaner 1 spot vs another. Again 1 way is after market smack easy & other is BETTER less drag less fuel burn works at any speed but harder after the fact to improve.
comment 134: only use the vortex gen on 1 wing of tiny ultra light craft. Then on opposite side of the elevator: God.If u can fly stead above 200+ then u can start to add vortex on both sides right & left wing but only 2/3s of the wing not last 1/3, outer 1/3.
I was 1111 jumping off pnt said 12 is NOW 13 man child or actual child 12 or 13 months. 1111+100= 1211 & 10yrs ish battling fictional game world & darkness=1221(we hve seen that number b4). Opposite of 2112 the 1001 SON & my starting score.
I was working on spiritual project since late 2011' round the clock, so . NOW spiritually I can pen whatever I want & said did extra5 yrs & not 85 Abraham but did the full 90yrs I asked the Epic losers to do if not spared judgment special race if raptured out b4 turning 23.
When Epic losers turn 21 the devil is old game gone. If HE gets tossed & all rebellion on 101021' Far Better. His score was 12 a man boy jew or opposing jews, so 1212. David was opposing Israel & pro Israel in same life & there was an earthly split as well.
So those that can't make grade r my property to do as I will & judge ,curse or bless. Started back 143 comment:not 144 big deal number. Ran right past old ending & end times judgment but not new pen-ed ending.
5 life humans can go back fall back into heavenly if they tire of earthly. Going full circle for some angel to human back to eternal then to angel back in heaven.
Fictional world we r living in & every1 including my family in bad video game acts just so shutting doors or locking doors or anything my Bart Simson world your just living in it.
20yrs from 9/11/01' has fictional world math & play gone though, meaning in earthly since even if hs drop out loser will b earthly adult 21 soon enough(Son & Father, property soon enough). On earth they r mine till then bc HS graduate or not from 18(GOD7 & devil play) they r still in the earthly My property/rule.
If your fallen or opposing kingdom of GOD7 u r not playing eternal game score but opposing player & earthly satanic smack shit(what can we get away w/.) Well time runs out soon on this terrible video game what ever u say or do or what side your on. Darkness delete & max 4 lives for opposing team unless they r working it out themselves in Bonus time only if they can make the grade on their own. 5 yrs given & used to make peace or darkness & damned & hell bound used up NOW.
Many thanks for your efforts on this project guys - your research is heavily influencing my decision to likely steer away from selecting the STi wing with my S7 kit: If I can achieve a level of STOL performance close to that of the STi wing with the regular Super Sport wing and VG's - especially as I'll mostly be flying close to sea level - well that'll do me nicely.
Do you know of any one else who's been able to verify your results on another Kitfox S7 SS? When I visited Kitfox last October, I mentioned this video to John McBean and he, (much like the UK LAA's Chief Engineer who I also mentioned it to earlier last year) sounded quietly enthusiastic about your results. John suggested someone in the US *had* achieved similar results, but I don't recall who or where they're based. FWIW, I don't think it was Alex Di Sessa; I see he mounted his VG's even further forward on RedFox in this video: ruclips.net/video/XPC8egjwjY0/видео.html - which I can imagine is less effective at higher AoA.
Btw, It would be great if you could add the VG manufacturer names to the info section too please. :)
And the $64M question: who did kill off your 'VG's can kill you' vlog? Google search is like it never existed - except on three Russian spam sites.
Keep up the great research! :)
Hi Hamish!
First of all that's for the amazing feedback, we really appreciate it!
Sorry for the VERY late reply!
But we are in the process of doing this on another KitFox Ss7 here in South Africa, we will most probably make a follow up video - don't know about anybody else who has done it according to our method though.
For the VGs we used Pacific North West's.
And to answer the $Mil question, we decided not to complete it because we covered most of the topics in this video... It's just important to do your research and not just spit and paste a bunch of things on your aircraft because someone said to - because it can make a huge difference in the handling of your aircraft!
@@About2Stall No worries at all - we're all busy :) Thanks for the VG manufacturer info. Here's a link to Pacific North West for anyone else interested: www.pnwaero.com/kitfox
Looking forward to the follow up video. Many thanks again for all your efforts guys! :)
Hamish Mead I’m in the middle of doing it. Probably be done in a couple weeks. I’ll report back.
c noz Awesome - look forward to it!
Alex Desessa's is a 4.
Different wing.
This was a great video & highlights how important it is NOT to mess around with the design of your aircraft unless you are experienced & fully understand the principles. You guys nailed it, but given that I am a low hours pilot I don’t think I’ll go out & stick a VG kit on my aircraft just yet!
It's fascinating how much something as small as a VG can affect the handling and characteristics of your aircraft! Thanks for the feedback! 😁
Evidence based data backed up by well-done testing of their hypothesis to prove the concept. Will definitely change the position of my VG's on my Highlander wing to rib based and add the roof. Nice to know the gap seal needn't be fancy but can be 3M clear tape or duct tape if appearance is of no issue. No airfoil is left unattended makes total sense to me. Great work and please keep going with the top gas cap work as I am at a loss on how to attach that to the wing.
Thanks for the time you took doing the research and testing on the vortex generators. I have a ss7 kit coming this week and am gathering all the information I can.
That's awesome! Enjoy 🔥
Thanks for the feedback Harry, we really appreciate it 😁
Wow great video, really enjoyed it. Solid research like this really helps the community.
Thanks KitfoxMan! I am glad we could help! 😄
Great video and report. Thanks. For my Gap seal on my Kitfox 4 elevator I used clear Gorilla Tape (brand name). Does the job and doesn't stick out like a sore thumb. Gap seal was a huge improvement. I have not done the vortex generators yet but planning to. Thanks for some great info!
Hi Teddy!
We have a nice permanent solution that we will release very soon. Main objective to be simple and as you mentioned... not stand out!
Thanks for the feedback!
i love the voice over. it makes it really nice. You making SA proud
Thanks Griff!
We tried making this "Technical" video as entertaining as possible, so really glad you liked it!
My tail design w/scoop that Ferrari scoop lets air from right travel thru tail & same the other way to keep balanced flight. The rudder needs 3 deg of free flutter per side, & u put vortex on the front of the tail not sticking out but serrated cutting lacing the air along the tail, locking it in. & it generates less shoot serrated thinner tail drag while more control.
Very nice results, I found the most interesting part was about the roof. I had a loose plane to actually raise my turtle deck and aft portion of the plane so that it was a straight line from where your VGs are to the tail. After reading some NACA documentation, that angle should be 7 deg or less and I think the way it drops down, it's closer to 11deg.
I have a composite leading edge that goes make 200mm from the leading edge so I don't have the fabric dipping between the fabric of the ribs. I wonder if moving my VG's between the ribs will still make a difference... I think my VGs are currently 50mm back. I am going to tuft my plane very soon so I should play around with the wing tanks distance as well.
Thanks for taking the time to do this. I have a lot of mods for the Kitfox that I want to do. The one that I haven't come up with a solution yet is to get rid of the gap between the horizontal stabilizer and the vert stab and have a root fairing while still being able to move it..
Hi Josh,
Thanks for the feedback.
The roof was indeed very interesting and we will be installing a wing fence between the roof and the wing in the next week to try and delay the stall a bit more. We also flattened those little corners that stands up to fold the wing under the roof. Didn’t make a difference.
We are working on a very effective permanent DIY solution for the gap at the horizontal stabilizer, we tested it on a mock-up setup and it looks promising. Once we are happy we will be sure to post a video.
And the next part is just to tease you :P… but we have a very simple but radical mod that we will be implementing in the next 2 weeks that should give us another 2kt off the stall.
The best thing about the VGs the cruise didn’t change…
Keep well! Fly Safe!
Great video guys, very informative and the tufting really helps to show the differences. Did you end up keeping the stall fence? Did you try any other positions or more than one for it?
Hi John, thanks for the feedback. With the tuffs we could clearly see the line of the stall and how it pulls at the rest of the unstalled wing. After installing the fence, the stall was contained to the stalled area. We are busy installing a second fence between the roof and wing.
What improvement did you notice from the vg’s on the roof? If you mentioned it specifically, I missed it. Thanks for taking the time to work on this!
Hi Texas STOL,
There were two improvements.
Firstly - At some stage before adding gap seal we could not stall her anymore because we lost elevator authority. She would pop up like a balloon at the tail - The weirdest feeling - By adding the VGs to the roof this happened at a lower speed and not such a BIG pop.
Secondly - this actually makes your stall speed lower. The first air to detach from the aircraft is the roof. And if that goes it starts "pulling" the air on the wing, basically inducing the stall.
So by delaying this, we delayed the stall. We will be installing a wing fence between the roof and wing to improve this even more...
Hope this answers your question.
Loved the video. Great research, great information, and great flying.
Hi Bart!
The flying was the most fun 😄
Thanks for the feedback!
Guys, this is an awesome well researched video. I am going to do the same to my Kitfox 7SS. I have few questions:
1. Did you do both sides of the rudder? Elevator?
2. Would you be willing to share the drawing of your wing fence?
Many thanks for the detailed information and research!
Well done, if you get the stall only a little slower, you will be able to tell the passengers that they can climb out and start walking on final approach. Regards
😄😄😄 We have a plan to take off two more 😄😄😄
Great informative video. Have you thought about a wing cuff from the wing tip to either half way down the wing or to the wing fence ( similar to the Icon A5 ) and vortex generators from the wing fence to wing fence. Will be interesting to see how it effects stall and STOL characteristics.
Hi Regon,
Yes we did look at a wing cuff, we are busy getting a slat. The problem with adding a wing cuff from wing tip to the half of the wing is that it will only improve the outside which is already working great. The stall will still happen at the same speed on the inside of the wing(our problem area). Before looking at any improvements on the outside, we need to improve the inside. So putting a slat the entire length sounds like a great plan 😀
I would like you guys to review a Superstol XL
Great video! A lot of great testing and information here. I am curious if you know whether or not the same spacings and placement would work on a Just aircraft Highlander wing? Also. Did you ever come up with a solution for the fuel cap? Maybe a fuel cap fairing in front?
Thinner less drag is the goal BUT even though air foil IT NEEDS High & lows at the ribs subtle diff at med speed & greater thickness at lower speeds.
The only question I have is at the end 10:00+ landing, shouldnt the root stall before the tips so that outboard aileron control is maintained.
Yes I realize it is flapperons.
But a full span simultaneous stall is unsafe.
EXCELLENT VIDEO 👍👍👍
Thanks!
You are correct, that's exactly why the VGs on the root side of the wing fence is further back than the other. This allows the Root to still Stall first while also improving the Stall Speed of the inner wing relative to what it was...
Hope this makes sense?
@@About2Stall I was just watching the yarn during the landing.
4k hr CP/AP
Great job guys!! tons of fun work.
Thanks for making this awesome video. Do you know if the wing on a series 5 Kitfox is the same as the 7?Would it be possible for you to make the cad file you used for the stall fence available for download? Also, it looked like you used a different VG on the roof section? Also, I used 3M blender tape for my gap seal and it works great, just need to put some Vaseline on the hinges so it doesn’t stick to them.
Most guys don't do the roof or the vertical stab. Good thinking.
Hi Rjh!
We really studied every test flight to see if we are improving. And there was many of them! Once you stop worrying about airspeed and actually look at what the air is doing...
Thanks for the support!
Did you notice a reduction in your cruise speed after installing VGs?
Have you tested something similar in an Avid Flyer early model with STOL wing? I'm thinking to start to experiment
Great video on the VG’s, who did you have cut your wing fences and how did you install them on your wing?
Hi Leslie,
We first shaped it out of wood, until we had a nice fit. The position where we saw we needed to install fence was inline with one of the flapperon attachment arms, we hooked it over the leading edge and bolted at the flapperon arm. Doesn't move much but to be sure we added 3 90degree 1cm feet. They are attached with double sided tape.
The final one was made out of aluminum and powder-coated.
Hope this help?
Thanks that’s what I needed, starting to measure an draw them up.
What thickness of aluminum did you use? Thanks
Also, how tall is your fence? Thanks again
Great informative video. I have a Kitfox V Safari I would like to have you guys recommend the setup for the vortex generators on.
Thanks
I have a Aerocomp MerlinGT. It is very similar to the Kitfox , I didn’t see what the final spacing is between the spars. I will be putting VG’s on mine really soon. Would like all this info , but I don’t see it.
What a great video…. I am the first customer to have the new Rans S21 Outbound flying.
I was hoping for A little slower stall speed but it always seems to come in at 45 mph, so I’m getting ready to install my VG‘s based on manufacturers (STOL Speed) suggestion a placement starting with the leading edge of the VG at 7% but they are using 90 mm spacing on the inbound portion of the wing and at the tips they use a 30 mm spacing I am wondering if going to a tighter spacing would have better results? If you have any thoughts on that it would be greatly appreciated also I believe after watching your video I’m going to install them across the top of the fuselage on my window area.
Thanks again for a great video, your results are quite amazing.
Hi Tailwheel Flyer,
Thanks for the feedback!
***First a word of caution***
It is extremely important that the inner section of the wing stall first. If it is not the case this will result in a stall spin scenario.
Only after many visual tests with the tuffs did we moved them closer at small increments and each time recorded on video the stall order. Making sure that the inner wing stalls first. We continued doing this until we could not move them any closer. And still saw the inner wing stalled first. This will differ from one wing design to the next. The kitfox wing is just so well designed to stall in the inner section. This may not be the case with your wing.
The recommended layout is usually safe without having to test. As soon as you deviate from it. You will have to test in very small increments. And before changing anything, really get to know your aircraft - it usually takes about 200 hours or 1000 landings 😊
Also the location of our wing fence, was with the help of visual results from the tuffs, you could clearly see the line between the inner and outer wing during the stall.
If you have any questions, we will be glad to help.
Safety first!
@bradgoff7301 I also have a 21 and have been thinking about VG’s. What are your results? I definitely can’t afford to lose any cruise speed.
I love it! Nice research... I wouldnt mind trying those stall fences on mine to see if they make a difference
Hey Nic!
Will send you the drawing as soon as we adapt it for the KitFox 4
Fly safe, keep up the lekke movies!
For those not familiar with Nic... he is one of our vlogging friends in SA...
Check out his channel:
m.ruclips.net/user/NicHolmes
About2Stall the IV and 7 wing should be the same wing design.
7:50 loosing fuel in a side slip ???
Holy schitt !!!
What kind of fuel caps do you have??
The standard KitFox caps...
Can I get a copy of the wing fence drawings or will you sell a set of wing fences ?
Seems like a test that no one is doing is comparative touchdown distance from a 50' obstacle. Would love to see how reducing stall affects this distance.
Reduce stall will definitely reduce that distance. But your result on a landing will be more dependent on the skill of the pilot and changing anything takes a few hundred landings to perfect the landing. Think thats why its never in the test video.
But if you think about it: a lower approach speed and keeping the same rate of decent will result in a steeper angle of approach and will result in a shorter touchdown distance.
Thanks for the feedback. We appreciate the support!
This is so good. Love the thorough research. How i wish i could get a flip.
Thanks PietPompies!
I thought after showing those deep stalls that no one would want a flip anymore 😄😄😄
Great vid. Well researched. I am building a Rans S20. About 1 yr from flying. Would like to do something similar when she’s done.
Thanks Martin!
That's awesome, keep us updated on your progress🔥🔥
So instead of adding aluminum drag BS the better way is serrated leading edge shoots making adding on new sheet metal to the both sides right & left if flying faster than 200mph, slower only 1 side.
What did you use to attach the VGs? Double sided tape? Or, loctite? Thanks again!
Hi Cameron!
We used high quality double sided tape (for easy removal while testing). We do however recommend that you go for a more permanent solution once your placement is final.
well done, a lot of good research there.
Thanks for the support StertSleeper!
😄
Like your original user name!
@@About2Stall yeah, here in the Cape vg's are a pain to land in a screaming south easter, just as you are finally settled it wants to jump in the air again.
I would love to have a constant 30kt wind.... we would be able to land in slow-mo!
Think this sounds like a movie!
"Fighting the "Doctor" to land"
-For those not in the know: the "Doctor" is what the locals call the famously strong south easterly wind.
would you recommend any major changes to a kitfox model 3 wing? I'm not really familiar with the model 7 wing but the 3 has a fair bit of undercamber. Otherwise I'm not sure what the differences are exactly.
Hi Eldon,
Thanks for the support!
It will be reckless of me to apply the knowledge that I have of the SS7 directly to the kitfox 3. If there is one thing we learned is that small changes makes a big difference.
My main concern is the difference in the inner wing. The 7 was almost over designed to stall at the root. So VGs had very little effect on this section. So a tight spacing worked. But on other wings not so overly designed to stall at the root doing the same placement will invert the stall. Having deadly results.
I know there is many kitfox 3 out there so I will definitely do some research to assist. Will revert in due time.
Keep well! Fly Safe!
Awesome video and great info, keep it up.
I’d love to know this information about my plane. How did you attach the VG’s I order to remove them without any damage? I fly a 1956 172 with an Alaska bush tailwheel conversion, and Horton stol. VG’s are next on My list. Great video. Thanks.
Thanks for the great feedback!
Before I tell you how we managed to remove them so many times…
I have to caution you!!!
Just as awesome as VGs are… they can change your stall characteristics in such a way that you can lose control on a routine stall exercise. We are busy editing our video “VGs can kill you” where we talk about the dangers of installing VGs incorrectly. Stalling your aircraft is never a good idea!
For testing purposes I will use aluminium VGs for the simple reason, in the beginning we removed the old 3M double sided silicon based tape by hand. After round 3 I had blisters. So I hired someone full time to do it. We did it more than 50 times. We tried every position you an think off.
Then when I had to do it again I tested every possible way to remove it. Tried cooking them, tried ultrasonic cleaner… And then finally, put them in paraffin overnight and the silicon falls of in the morning. Necessity is the mother of all invention.
So use the aluminium VGs with 3M 1mm double-sided sheets. We used a gelatine to cut then to size.
To remove them make sure you leave the aircraft in the sun for a few minutes. If you try this while it is cold, it will take some paint with it. We then used a twisting motion to remove them, not a pulling motion. You will lose paint if you pull them off.
We found that a VG pair works much better than singles. It is when you place them to close to objects or changes in the wing that a VG can actually increase the separation of air. We found to keep at least 30-40mm from all changes in the wing. This counts for pair and singles.
The best way to test is to install tuffs and record a stall in all 3 configurations so you can understand how your wing works. Then use the recommended installation by the manufacturer. Again do stalls in all three configurations. Look and study the footage make sure that the placement they recommend keeps the stall order and pattern the same.
Even if you get slower stall speed and the stall pattern is not the same or better… TAKE THEM OFF. It is not worth the slower speed.
After ever small change we did, no matter how small(6 months), we recorded a test flight with a very fast stall(release back pressure at first signs of stall) to make sure we are moving in the right direction. We have so much footage of a kitfox stalling, I think we will put it in a stall compilation.
I hope I didn’t bore you with too much info… I will go read up on your aircraft to see what has been done with VGs.
Keep well! Be Safe!
About2Stall thanks for the advice. You defiantly have a lot of great knowledge about this. I love the scientific approach.
Have you or would you do a study on the placement of the VGs on a Zenith 750 STOL?
Thanks Robert Ess
We have some friends with a Savannah, which is very similar... So well probable do it in the near future!
Good vídeo ! Can you add some telemetry next time ?
How does the kitfox ss 7 compare to the kfa safari?
We're are making a comparison video soon!
Hopefully that will answer your questions 🔥
I am building a kitfox ss7 standard wing with the Laker leading edge, would you install the pacific nw aero vg's in the same way you are showing ? Thanks so much , billy
Hi Billy!
It's difficult to say how the leading edge will affect the performance and installation of the VGs. But I think it should work just fine. We used the ribs in the wing as a reference for placing the VG pair, as mentioned in the video. If you can still reference the ribs in that same way for the install I think it should work great, mabe even a bit better given the surface wil be "smooth" compared to ours.
Would love to hear your feedback, if you do decide to go with our Installation
@@About2Stall Thank you very much for the reply. I agree with you that the Laker Leading edge should be a good system for your design and study of the VG's. I am the oddball ..... going with the 160 HP Lyc., whirlwind prop., so I am 100 lbs., heavier right out of the gate, and will share my data with you when I have some. I would expect about 3 months from now. and while I am writing this, a question for you ..... have you developed a elevator gap seal yet ? I Thank you and your team for this extensive flight data you are sharing with all of us , you guys are the BEST !! billy
Absolute pleasure!
Yeah, that is a bit different than the norm... Really curious what your performance numbers will be.
We have a prototype of the new Gap seal, but we're still in the testing fase. Will keep you updated once we have it ready.
It's our absolute pleasure sharing our research. That's how we all contribute to GA!
@@About2Stall Hello again,
I received my airworthiness Certificate last week and ready to haul my Kitfox to the airport. I am asking if you have completed your gap seal project yet? I would love to use them since I copied your VG layout. Keep the fun alive !!! Billy
Bakgat,ek geniet julle videos man.
Julle moet bietjie kom kuier hier in Potchefstroom en saam ons kom sweef!
Dankie vir die terugvoer AJ!
Mens weet nooit of mense daarvan sal hou nie - So ons waardeer julle ondersteuning!!
Ons sal definitief só iets moet doen! - Hou ons Sosiale Media dip, dan reël ons dalk só iets!
Sweet video, Keep it up!
Hi Jason!
Thanks for the support! Comments like yours make sure we do 😄
I keep reviewing this video, thanks again. How many did you put on the rudder? And, what spacing?
We have 10 on each side of the vertical stabiliser 5 pairs of 2. I'll have to confirm the spacing and get back to you!
OK so they are evenly spaced between the ribs, 10 in total, hope this helps?
I yearn to see the build video of your homebuild aircraft.
Hey Jeff,
We just bought a 13 year old abundant Jodel D11 half build project... we will be sure to share the experience of breathing life into her!!!
Have you finished developing your gap seals? Thanks
Great Vid and Info...should help alot of people out.
Thanks Suprdave123!
We're hoping that it will!!!
Great intel. I have IV Speedster and would love the math on that set up.
DREAM BIG
FLY HIGH
LIVE THE ADVENTURE !!
I love it.👍👍👍👍👍
🇺🇸🇺🇸🇺🇸🇺🇸
Our motto we live and swear by! 😁
Thanks for the support!
Very informative, thanx for sharing.....
Hi Drew,
Its a pleasure! Thanks for your support!
Awesome job and tons of useful info. On a side note,lose the crummy music on future vids.
Thanks!
Our music has improved alot in our latest videos, thanks for the feedback 😁
How did you attach the fence to the wing? And what material did you use?
Check out the reply to Leslie Rice :)
Awesome video, thanks for the effort.
Cool video, thanks for the info
Thanks for the support Paul! We appreciate it!
Have you tested the vg's on a rans s7, and if you have, where would I find the results? Thanks Gary
Hi Gary, no we haven't tested the Rans S7 but if we can get our hands on one we will definitely look into it!
@@About2Stall S-7's have had the placements of VG's figured out for 20 years.....get on the Facebook S-7 site.
In a stall if 1 wing is lifting other is tipping & gaining lift by default, so no need to drag both wings BS to get improvement.
fast drone chase cameras make sure u get good data/footage to test it out.
Wow ... You guys went all out on vortex gen research for this airframe .. more so than any other group or individual worldwide to my knowledge ... At the time Im making this comment you have 3,845 views .. rest assured this will surpass 100,000 , likely before the year is out . You have no idea the demand for this raw data from backcountry pilots worldwide but you soon will
Thanks Mark!
We really appreciate your support and feedback!
It was about 6 months of research that went into this video - so glad it was helpful.
@@About2Stall Helpful !! It is unprecedented what you have done ... This reads like a research paper for ones PHD ... Its not just another flying / entertainment video ... which don't get me wrong we dang near live for those ... This is something else .. something that takes extraordinary time and effort as you mentioned ... and the results are of great value ... Its like your giving away an intellectual property ...and we cant believe its free .... Helpful !! Ya thats an understatement ... My plane is getting this South African treatment
u want thin ailerons but as u saw w/wing tests sometimes ribbed ultra thin beats thicker wing to fight stall thin is better less drag yo!
No comment whatsoever of pitot error at high AOA?
If we had to go into everything there is about aviation in one video I am sure it will be way to long... but please feel free to add your expertise, that way we all help grow GA!
We are planning a follow up in the future, will definitely explore that aswell!
Great video. How many vortex generators did it take to do both wings and the roof?
Thanks🔥
There's about 80 per wing,
40 on the roof and
16 on elevator x2
So 236 total
@@About2Stall thanks... Looking at doing the same on my Kitfox 7SS
@@About2Stall ready to cover my SS7 wings , great videos, Thank You for all the info.... Could I get a sketch or print on placement for those 236 VG's. Cell 360-914-0014 Washington State, Would be very glad to pay for them, You have done a tremendous amount of study and investment to the Kitfox world of aviation. If I could pay for some of your work ,I would gladly do it !! cheers, Mark
@@About2Stall Hi Riaan, are you able to supply the wing fences you developed for your Kitfox?
The key to making a strong safe low stall wing or rear wing is but u cover the ribs^
Where are you located
South Africa, Nigel.... 😄
Netjies Riaan. Is jy dalk familie van daai DIY tannie😂😂?
Hahaha! Ai my vriend! Dankie vir die support!! 😀😂🤣
Time that you get back in the air!
Which aluminum VGs?
We used PNW Aero's VGs
the left side wing gets no vortex generators for these small craft but gets serrated leading edge shoots. It is opposite way to make vortex only 1 is cut shoot out & other is cheap shit but Works add-on. The cut-out is less after market new design but is better way less drag to do the same thing. 1 wing no wing or above 200mph both wings but ony 2/3rds of the wing.
👍 👍 👍
Thanks Freddy!
the tail on this high wing, bad design, needs a snailing strong Kevlar fabric over that makes plan 3 or 4 ft+ longer. The fabric over wire shock lets some air in & adds no real weight & very little drag but great free flowing control, needing no imput.
your making a Ferrari scoop only by DRAG adding on vs new design serration so air is cleaner 1 spot vs another. Again 1 way is after market smack easy & other is BETTER less drag less fuel burn works at any speed but harder after the fact to improve.
comment 134: only use the vortex gen on 1 wing of tiny ultra light craft. Then on opposite side of the elevator: God.If u can fly stead above 200+ then u can start to add vortex on both sides right & left wing but only 2/3s of the wing not last 1/3, outer 1/3.
I was 1111 jumping off pnt said 12 is NOW 13 man child or actual child 12 or 13 months. 1111+100= 1211 & 10yrs ish battling fictional game world & darkness=1221(we hve seen that number b4). Opposite of 2112 the 1001 SON & my starting score.
back from 1 earlier, went touch over & 2 laps comment 162:
NOW 1212 is most in heaven ruling class chairs & on earth devil max-ed out just same.
The earth is about to b opposite Heaven no more, a work in progress till SON76 of GOD's return.
Lekker video - dankie. Wil ook n kitfox koop - enige voorstel dalk ? frederik.kruger@gmail.com
Dankie vir die terugvoer Frederik, waardeer dit!
Sal vir jou 'n mail stuur👍🏼
I was working on spiritual project since late 2011' round the clock, so . NOW spiritually I can pen whatever I want & said did extra5 yrs & not 85 Abraham but did the full 90yrs I asked the Epic losers to do if not spared judgment special race if raptured out b4 turning 23.
When Epic losers turn 21 the devil is old game gone. If HE gets tossed & all rebellion on 101021' Far Better. His score was 12 a man boy jew or opposing jews, so 1212. David was opposing Israel & pro Israel in same life & there was an earthly split as well.
Women r ppl in NOW & she max-ed scored & I max scored. Me working like demon possessed & she just showed up bad video game playing along & won.
So those that can't make grade r my property to do as I will & judge ,curse or bless. Started back 143 comment:not 144 big deal number. Ran right past old ending & end times judgment but not new pen-ed ending.
5 life humans can go back fall back into heavenly if they tire of earthly. Going full circle for some angel to human back to eternal then to angel back in heaven.
Fictional world we r living in & every1 including my family in bad video game acts just so shutting doors or locking doors or anything my Bart Simson world your just living in it.
20yrs from 9/11/01' has fictional world math & play gone though, meaning in earthly since even if hs drop out loser will b earthly adult 21 soon enough(Son & Father, property soon enough). On earth they r mine till then bc HS graduate or not from 18(GOD7 & devil play) they r still in the earthly My property/rule.
If your fallen or opposing kingdom of GOD7 u r not playing eternal game score but opposing player & earthly satanic smack shit(what can we get away w/.) Well time runs out soon on this terrible video game what ever u say or do or what side your on. Darkness delete & max 4 lives for opposing team unless they r working it out themselves in Bonus time only if they can make the grade on their own. 5 yrs given & used to make peace or darkness & damned & hell bound used up NOW.