Micro Aerodynamics Vortex Generators, Stall Testing VG's

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Күн бұрын

Scooter added the Mirco Aerodynamics Vortex Generators to his Stinson 108. This is part of his Stinson STOL project, hoping to enter the Stinson in a short field competition or two this year. The Micro VG's are only part of the project. Uavionix AV-20S for the AOA and density altitude readouts, Skytec starter, lightweight wood prop are all currently in the works. Future plans include a lightweight alternator, lightweight battery along with other weight loss plans. Larger flaps are illusive if anyone can get a set approved for the Stinson we know someone who wants them.
Keep watching this channel for more updates.

Пікірлер: 30

@Subcanis 4 жыл бұрын

I put them on my -2 this winter. I didn’t record before and after numbers but I did find that power-on no-flap stalls yielded an actual break whereas before it just sort of mushed and set up a very high AOA rapid descent. Power off full flaps felt much the same as before with one huge exception... much more elevator authority. I always felt that I was stalling the elevator during the flare in power off approaches and either required excess airspeed or significant shots of power to arrest the descent. This seems to have significantly improved that. Full stall landing attitude seems to be more nose up indicating an increased stall AOA. I’m pleased with the results.

@GreatMichiganBushCo 4 жыл бұрын

Yes, even with a little bit of power it seemed to break harder. That was good, it will allow for higher AOA approaches. I wanted to know if there would be a difference that's why I did the first stall video. I will also do another stall video after the plane is 75lbs lighter.

@Subcanis 4 жыл бұрын

Great Michigan Bush Co. what is your current empty weight if I may ask? Using CAR 3 w&b rules (no oil, 4 gal unusable) I’m at 1385.

@GreatMichiganBushCo 4 жыл бұрын

@@Subcanis I show 1394 with the rear seat in. I fly without the rear seat -23lbs. So I am flying with an empty weight of 1371. I will loose 20lbs with the wood prop and 2lbs with the spinner gone, 10lbs when I change the starter, I will replace the battery with a odyssey loosing another 15lbs. All this is one the way... So soon it will be flying at an empty weight of 1324lbs.

@andyspandy5317 2 жыл бұрын

For the elevator autority would not be enough to install the VGs on the tail?

@jimhrabetin1565 6 ай бұрын

I’d have liked to see a slow flight comparison as well. Nice video. Thanks.

@GreatMichiganBushCo 5 ай бұрын

The slow flight would be difficult to quantify. You can control the aircraft down to steal speed. On that note it is noticeably easier to control with the VG's. Some folks disagree with that assessment. When I first started flying I thought VGs were voodoo, now I find them to be one of the most affordable upgrades you can add to an aircraft.

@blainemacdonald6929 2 жыл бұрын

There is a stinson for sale on kijiji right now in Canada with droop tips and wing fences looks badass! It also has a 470 continental and what looks like a cessna 180 cowl

@lindsaylittle6535 4 жыл бұрын

Very,very nice video on your VG's! I wish I would have had a chance to put them on my straight 108. One of the most undervalued and safer airplanes made. glad to see that they included the VG's in the slotted area of the wing. Your editing is getting really good. Glad to see you back! Greetings from the Arrowhead of MN.

@GreatMichiganBushCo 4 жыл бұрын

It is a very undervalued and under appreciated plane. I think it is the best value in a bush plane you can find. Thanks!

@zerocoolak 4 жыл бұрын

Love the vids man. Learning to fly now in a -3. Keep them coming.

@GreatMichiganBushCo 4 жыл бұрын

Thanks! Will do!

@aerobatgaming2033 4 жыл бұрын

Two guys in my local EAA chapter just bought a 108-3 and we ran the engine and taxied it for the first time in 20 years on Wednesday

@PARTner91 3 жыл бұрын

I recently subscribed and I’m enjoying your videos. It’s awesome to see the difference the VGs made on that Stinson. The math geek in me found a minor error on the chart shown towards the end of the video. At 1800 rpm, flaps 1, the % change is not 10% but actually is a bit over 14%. That’s phenomenal change! Keep up the great videos 👍🏻

@GreatMichiganBushCo 3 жыл бұрын

Thanks for watching and subscribing. I'm glad you're enjoying the videos. I've been known to makes some math errors, glad you caught it.

@nickxidis9571 4 жыл бұрын

Nice experience report. Landing into a decent head wind should be really short.

@scottanttila8462 4 жыл бұрын

Nick Xidis a nice calm wind directly on the nose sure help ... If I could get a smooth 30pmh on the nose it’d be under 50’ 😀

@brettgerber795 3 жыл бұрын

With the VGs installed, has your pattern speeds decreased on downwind, base & final or still fly it like before but just touch dish slower? I had a set on my experimental Long Ez and helped on the touch down speeds. Looking and trying to educate myself on the Stinson. thanks for the videos!

@GreatMichiganBushCo 3 жыл бұрын

I slowed the final down by 5 -6 MPH. I kept the same speed around the patter. I could slow down a lot but there is no need to go slow downwind :-)

@reidbaldwin4555 3 жыл бұрын

There is a pretty significant reduction in indicated stall speed with more power. Do you think that is real speed reduction or airspeed indicator quirks?

@GreatMichiganBushCo 3 жыл бұрын

The indicator at high AOA becomes unreliable for actual airspeed. You are converting thrust to lift at high pitch angles so your stall speed will reduce noticeably.

@dbloemer 3 жыл бұрын

I don't (yet) own a Stinson, nor have my tailwheel rating, so have a comment and a question for this. My understanding is that a "perfect" three-point tailwheel landing includes touching down exactly as the plane slows to and reaches full stall, exactly at your planned touchdown spot. If the MicroVGs make the stall break more crisp and abrupt, doesn't that make "perfect" three-point landings more challenging - forcing you to plan the last bit of the approach a little bit faster than otherwise, to avoid unexpectedly losing that last knot (mph if in a Stinson) a couple of feet above the runway (e.g. gusty headwind), followed by a rapid nose drop and crunch? Secondly, I wanted to point out that landing energy is based on the square of the velocity, so for example your power off flaps 2 stall speed reduction from 41 to 38 mph is a 16.4% reduction in kinetic energy even though it is only a 7% reduction in velocity. The kinetic energy reduction defines the landing roll, not the velocity reduction, since during the landing rollout you are using drag (aerodynamic and braking) to burn off that energy until you reach zero kinetic energy when stopped. At 1800 RPM and flaps 2, the energy reduction is 21.8% vs. 1800 flaps 2 and no VGs, and your touchdown energy is 141% lower than a no-flap, no VG, power off landing, which should translate to a very significant landing roll reduction (although some of the savings will be lost in reducing the RPM to idle after touchdown). I'd love to hear any corrections or comments about this, thanks!

@GreatMichiganBushCo 3 жыл бұрын

First off no on the "Prefect 3 point" and not working well with the VG's, Your concept is correct but application is different. There are a lot of things going on in a 3 point landing and a slower more clean break would be desired. People write books on this stuff so it's a lot to talk about on a reply to a comment on a KZfaq video and I can't get into it all here. A points for thought though, the 3 point stance will not always be the "perfect" attitude to stall, the angle of the aircraft to the ground will be different depending on power settings and weight. The gust windy situation is taken care of with adjustments on approach speed by adding half the gust factor. A couple things happen. When gusty your ground speed is reduced because of an increased headwind (talk about energy reduction think about a15mph headwind wind) so the addition of a few MPH for safety doesn't hurt and you'd add that to the non VG approach speed anyway. When the winds are to gusty and turbulent some landing areas just become unsuitable. As for the energy you are correct and all STOL pilots understand the effects of lower speeds on landing roll even if they don't understand the entire energy picture. The RPM to idle really ads nothing to the landing roll since most of the energy is going to induced drag and a recip. engine idles down almost immediately. What the VG's did for me was reduce my landing distance from about 250' to 200'.

@reidbaldwin4555 3 жыл бұрын

The problem with landing on the front wheels first when you are trying to do a 3-pointer is that your vertical inertia causes the angle of attack to increase as the tail comes down. If you are above stall speed, that will result in an increase in lift causing the airplane to go back up. If you are at or below stall speed, the increased angle of attack does not increase lift - it decreases it. So the airplane stays on the ground. Gusts are always an issue for 3-point landings, VGs or not. That phase where your speed is within +/- the gust factor of the stall speed can be treacherous. Being in a high drag configuration with power off makes that phase as brief as possible.

@MrOneTango 3 жыл бұрын

how did the VGs effect your cruise speed at a given power setting?

@GreatMichiganBushCo 3 жыл бұрын

I didn't notice anything appreciable. It definitely fell into the noise of density altitude, weight, CG, another performance factors. Now the 3-in I took off the propeller pitch... That was noticeable.

@Bushmasterpilot 3 жыл бұрын

Can you make me some of those, Made in Detroit, decals for my 108-3 up here in Canada?

@GreatMichiganBushCo 3 жыл бұрын

This is where I got mine. It looks like they have changer the form just a bit. Still s super cool on a Stinson. letterquote.com/products/made-in-detroit-workers-vehicle-decal-sticker?gclid=CjwKCAiAyc2BBhAaEiwA44-wW8RFhx-2-PwRc41TUVokTpRUFvrTuVNTeYEhW2bZt-Wvxe5xV-s_ghoCgPUQAvD_BwE

@Bushmasterpilot 3 жыл бұрын

Load er up to gross, and test again!

@GreatMichiganBushCo 3 жыл бұрын

That's a good idea. I'm. It sure I've ever had the wagon at gross. I know the old Stinson was a pig at gross weight, I'd expect this one to be similar.