Slats vs Slots pros/cons

What are the pros and cons of the hinged leading edge slats vs the fixed leading slots?

Patey did a discussion on that in the Draco build youtube videos.....

maybe this video?

Exp vs certified. How many exp guys choose slots? How many slot wings have beat slats in contests?

Personally I think Pstol flaps are the priority. Slats follow.

Good point and that is exactly the info I am seeking. Who is buying slats vs slots and why?

Me? Slats W/Keller flaps. Why? Because I haven't seen anything the comes close to the performance that slats and Pstol flaps offer.

Dakota Cub has wings with slots for certified aircraft, so far no certified slats. Both will hurt top end airspeed. Stewart, when you get the Wildcat back up it would be nice to do top speed with and without the slats. I have heard everything from 3-7 mph loss with them. I am sure slot rigging and balance has something to do with it. I will be happy to buy the beer if you are interested.
DENNY

Exp Super wide Cub.
0-320 170+hp
31” Tires, 3” gear with TK-1 shocks
Round tips
Catto 84x37
Carbon Fiber Slats

Before Slats I would cruise 92mph @2400
With Slats I cruise 86-87mph @2400

Slats are adjusted with bottom of slat cuff about 1” below bottom of wing...

cook11 said:

What are the pros and cons of the hinged leading edge slats vs the fixed leading slots?

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Fixed leading edge slats have a fixed rather high drag component.
A well designed hinged slat will blend into the leading edge at cruise speeds without a drag penalty.

DENNY said:

Dakota Cub has wings with slots for certified aircraft, so far no certified slats. Both will hurt top end airspeed. Stewart, when you get the Wildcat back up it would be nice to do top speed with and without the slats. I have heard everything from 3-7 mph loss with them. I am sure slot rigging and balance has something to do with it. I will be happy to buy the beer if you are interested.
DENNY

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I have seen a speed reduction in slats but we have a lot of time with stock wings vs the Dakota Cub slotted wing in my wife's Tri-Pacer and no difference in cruise speed what so ever. Bill Duncan thought the slot on his Maule was costing him cruise speed but he never taped it up to see.

The Globe Swift has a fixed slot built into the wing planform for enhanced aileron control at low speeds. There is an STC to cover this slot which claims to increase the cruise speed indicating reduced drag with the cover installed.

Steve
Was the slotted wing square? That should make it a bit faster than the stock round tip wing. Combine that with a slot and it should be a wash.

DENNY said:

Dakota Cub has wings with slots for certified aircraft, so far no certified slats. Both will hurt top end airspeed. Stewart, when you get the Wildcat back up it would be nice to do top speed with and without the slats. I have heard everything from 3-7 mph loss with them. I am sure slot rigging and balance has something to do with it. I will be happy to buy the beer if you are interested.
DENNY

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Honestly I’m not concerned with top speed or drag from slats. After talking to several experienced slat guys I used Backcountry’s advice and mounted my slats flush with the bottom of the wing. With that my plane cruises at 100 mph and stalls under 20 mph. That airspeed range works for me. My Cub wasn’t built for speed but it turns out its a fairly fast Cub that also flies slow. While the speed impact of adding slats isn’t important to me I’ll get before-after data the easy way. My nephew just bought a new SQ build that doesn’t have slats. When he gets it home he’ll be adding them. I’ll get numbers from him.

My slat hangers are attached to the wing using nut plates rather than PK screws. The purpose was to allow me to make different hangers to reposition the slats lower relative to the bottom of the wing. Since I’ve lost a year to the engine problems my interest in that experiment is fading. I just want to fly it. My new motor should make 15+ more hp than the old one. I’m more interested in that than fiddling with the wing.