I'm looking for opinions and pros/cons of each. All feedback is appreciated. Thanks.
I'm looking for opinions and pros/cons of each. All feedback is appreciated. Thanks.
After Monday and Tuesday, even the calendar says WTF !
A Slat is the airfoil shaped device which is placed ahead of the leading edge of the wing. The Slot is the space between the Slat and the wing. Some designs have the Slat placed ahead of the leading edge. Others have built the Slat/Slot combination into the area behind the original leading edge so that the original contour is unchanged. Their performance is essentially the same. The Slot works at high angles of attack helping to hold the air flowing close to the upper wing surface thus maintaining lift at lower speeds. This is similar to what the Vortex generators (VGs) do. But, in my opinion more effective.
N1PA
One is approved on certified Supercubs. One is experimental only. Which is more effective isn't in dispute as far as I can see. Applicability is the issue. Wayne Mackey's slats have probably done more for the experimental Cub category than any other mod I can think of. Dakota's slotted wing hasn't stormed the certified Cub market that I've seen.
I haven't flown the certified Dakota slot. I can think of several practical comparisons to Wayne Mackeys experimental slat, with which I am familiar.
Pro (con)
Your old wing covers might still fit the Dakota slotted wing. (the Mackey slat increases the chord length. need new wing covers)
The wind won't be doing any damage to the Dakota slot. (The Mackey slat is movable, so you might wanna lock it at the tiedown. your new winter wing covers will do this)
The Dakota slot is certified. (Mackey slat experimental)
Mackey slat is easy to install. (Dakota slot requires to build up a new wing with different ribs)
Mackey slat is relatively inexpensive. (Dakota slot relatively high-dollar)
Mackey slat easy to remove and repair. (Dakota slot?)
Mackey slat is relatively light (Dakota?, not that it matters, in my opinion. Most guys think a sparkling-performing Cub is predicated on lightweight, they might think the Dakota Slot would hurt performance, but several other things about a Cub are more important than simply light weight, so a Dakota slot's change-out weight for a guys existing wings is not likely to hurt the performance of that specific airplane. In fact it is certain to increase the performance in..........)
.....both slat and slot are certain to increase performance of the a/c by making it absolutely solid at the low-end of the flight envelope where a stock wing doesn't dare go. This solid flying quality allows incredible slow-speed maneuverability that is fun, fun, fun.
Anyone who thinks they wanna, oughtta get a demo or some stick time in a slat/slot airplane. You simply don't know what these do unless you ride in one. Its crazy.
Skywagon - almost but not quite. The slat is a secondary airfoil independent to the primary airfoil (wing). A slot is a secondary airfoil built into the chord of the primary airfoil (wing). A Stinson, Piper L-14 and the Dakota wing have slots; the Fiesler Storch, ME-109, Rallye and SQ2 have slats. The Dakota wing is essentially the same dimensions (except for the squared-off tips) as the original Supercub wing and the slot is built into the existing cord.Originally Posted by skywagon8a
As for differences between Dakota's slotted wing and the SQ2 slats - they are probably negligible. Besides the certified (Dakota slots) experimental (SQ2 slats) difference that has already been pointed out the performance difference is probably pretty small. Based on watching the SQ2 fly (slats) and having flown Dakota slots myself for many years I would say that the slats may be able to achieve a bit higher angle of attack than the slots. Either angle of attack is so steep at that point as to ensure a tailwheel first landing (i.e. dropping the mains on with the tailwheel already touched down). Where both slots or slats really shines is in their ability to KEEP YOU OFF YOUR BACK WHEN MANEUVERING AT SLOW SPEED AND LOW TO THE GROUND i.e. prevent stall spin from this condition. I remain convinced that many of our dear friends that we have lost to unexpected stall spins while low to the ground would be alive today if they had been flying slots or slats. This additional safety margin while maneuvering in the slow flight low altitude portion of the envelope makes them worth their weight in gold especially given what most folks are using Cubs for.
Some folks have equated slots/slats to training wheels but I say they are a big honkin seat(safety) belt. Do you want to stack the odds in your favor? Or do you believe that real pilots don't need seat belts because they a good enough to crash without getting hurt....
PS: Perry B - if you want a demo flight with slots and can make it to Washington you are welcome to go for a ride in my Cub. Send me a PM.
Stand your ground, don't fire unless fired upon, but if they mean to have a war let it begin here. - Capt. John Parker, Lexington April 19, 1775.
Gunny
The lower end of the flight envelope has been opened by these devices. It may seem sacriligious, but....... A stock Cub isn't even close to the lo-speed maneuvering tightness of a slatted Cub. And the slat makes it dumb-easy to fly it that way. Dumb-EASY!!........with very little worry.
Also, to add to Gunny's comments.........a slAt increases the wing area. In the case of the Dakota slot, the wing-chord is nearly identical to stock chord...
Hey Dave - instead of Dumb-EASY can we say Dumb-SAFE as in it will protect even the best pilots from those dumb little cross controlled stupid attacks that can just barely kill you...
Stand your ground, don't fire unless fired upon, but if they mean to have a war let it begin here. - Capt. John Parker, Lexington April 19, 1775.
Gunny
And I'll add to the above, to what a lot of pilots think that have never flown slats, they handle high winds very well.
I sure like the added safety margin when maneuvering low to the ground in high gusty winds.
You do have to make control inputs but you can levitate on.
Randy
I have a couple thousand hours on Dakota slotted wings. Just my personal experience, but Wayne's slats are far superior to the slotted wings. Just my 2 cents.
Last edited by Hoonahcub; 02-09-2012 at 08:12 AM.
It's nice to give Wayne all this credit but don't forget that he's just using what's been around since the 1930. Go fly a Tiger Moth, the slats lay tight against the leading edge till they are needed, you can lock them "in" from the cockpit if you want to do spins and unlock them to do there job, kinda cool watching them when flying, they are spring loaded when unlocked and while flying they don't pop out at the same time but do it when each wing needs a little help.
Glenn
I had Wayne put a set on an experimental back in 02. Like Dave said it is crazy the attitude you can put the plane in and and still be flying.
Slats have allowed me to land and takeoff in places that are very short but safe. They provide the ability to fly very slow very safely.
Lloyd
Glenn, Wayne has done some magic that none NONE of the other slatted a/c have had. He found a concept and changed it around. No Helio, Storch, or whatever posesses his unique recipe.
He deserves the credit.
Gunny, We will have to disagree. The Slot is the air space behind the Slat. It does not matter whether the Slat moves or not. There are many airplanes which use slots to enhance performance. I invite you to read the following: http://en.wikipedia.org/wiki/Leading_edge_slot
N1PA
Pete,
I have always been told that Slots are fixed, while slats are TYPICALLY moveable, either mechanically or via air pressure. I invite you to read the definition of slats on your favorite aerodynamics text: http://en.wikipedia.org/wiki/Leading_edge_slats
Where they describe a fixed slat as a "slot".....
Then again, a rose by any other name.......
MTV
Mike, From your source "...In reality, the slat does not give the air in the slot high velocity....". The slot is the air space. The slat is the hardware.Pete,
I have always been told that Slots are fixed, while slats are TYPICALLY moveable, either mechanically or via air pressure. I invite you to read the definition of slats on your favorite aerodynamics text: http://en.wikipedia.org/wiki/Leading_edge_slats
Where they describe a fixed slat as a "slot".....
Then again, a rose by any other name.......
MTV
N1PA
Pete,
From my source: "Fixed - the slat is permanently extended. This is sometimes used on specialist low-speed aircraft (these are referred to as slots) or when simplicity takes precedence over speed."
But, as noted a rose....
MTV
to muddle your pissing match....
....about the "secondary airfoil" and whether it's built into the existing one or what.........
Dakota's SLOT is part of the same airfoill. Wayne's SLAT is a separate, movable airfoil. agreed??? Yes!
Here's the muddy part........The Helio uses a movable SLAT that in cruise flight is part of the normal airfoil, but in slow flight moves forward, away from the existing airfoil, becomes independent, and leaves a kindof 'SHARP" leading edge on the 'mother' wing.
Skywagon and MTV, you guys ever fly a slat or slot??
slat, slot, slit, slice, whatever.... pretty sure by this point everyone knows who's talking about which one, and none of the semantics probably matter to the OP.
Dave or anyone else who has done both, I am curious which produces a lighter wing? Anybody got a definitive? Amy? Wayne?
edit; I guess that was a dumb question. Considering a guy could build up a set of 13 rib wings with Piper ribs, all else equal, the slats would likely be lighter...
Last edited by Rob; 02-09-2012 at 02:36 PM.
Exactly Dave. The key is within the existing wing chord OR independent/auxiliary to the existing wing chord. You can remove leading edge slats from a wing and not change the chord of the (primary) wing (airfoil). You cannot do the same with slots. That is the difference.
PS: On spam cans they are sluts and on Huskys - well I'm just not gonna use that type of language here.....
Stand your ground, don't fire unless fired upon, but if they mean to have a war let it begin here. - Capt. John Parker, Lexington April 19, 1775.
Gunny
Dave,to muddle your pissing match....
....about the "secondary airfoil" and whether it's built into the existing one or what.........
Dakota's SLOT is part of the same airfoill. Wayne's SLAT is a separate, movable airfoil. agreed??? Yes!
Here's the muddy part........The Helio uses a movable SLAT that in cruise flight is part of the normal airfoil, but in slow flight moves forward, away from the existing airfoil, becomes independent, and leaves a kindof 'SHARP" leading edge on the 'mother' wing.
Skywagon and MTV, you guys ever fly a slat or slot??
Yes, I have, but what's that got to do with poking at Pete????
Well, I've never flown Dakota slots, but have flown Wayne Mackey slats on about 5 airplanes. They're cool.
I'm interested about anymore that "Mr. 4Billion posts" (HoonahCub) has to say about the comparison of STock, DakotaSLOT, or MackeySLAT.
MikeV. anything to add? and what device? slot/slat?
Rob, Hi ya. Long time. D
Like Dave, I am interested in more of what HoonahCub has to say. It sounds as if he is our resident expert on the slotted wing. It doesn't seem like there are many sets of those around even though they are approved. Why not? My neighbor is still trying to sell a set.
What are you seeing for stall speed? Do you see any change in climb rate or cruise over stock wings? Have you had a chance to fly the slats? Sorry for the 60 questions buy I think we would like to hear more. Thanks, Greg
Slats - A couple of questions for the guys that own or have flown them.
Are the slats effective on a standard, round tip wing - or are there other wing mods necessary for the slats to be effective? Also, I've seen most of the videos with the cub flying at ultra low speeds with the nose pointed straight up into the air. This looks very cool and might win you the contest at Valdez, but other than that, we don't fly approaches like that into our favorite sheep strips. So my question is - are they a worth while mod for normal Alaska flying. Will I see any increased performance in landing speeds in normal landing configurations. Are they just for Valdez or are they useful in the real world? Sincere question. Thanks in advance!
Roger
I have owned 4 different airplanes with slats. Fixed and retractable. Most airplanes in this world have round tips with the slats! Boeing seems to like them. I will always have slats when landing in the bush. The wing will NOT stall and drop and it will fly much, much slower. What more can I say?
So is it correct to say that either one makes a much bigger difference than VGs do to a stock wing? And I suppose there's no way to put slats on a certified airframe.
Hope that helps.
Stand your ground, don't fire unless fired upon, but if they mean to have a war let it begin here. - Capt. John Parker, Lexington April 19, 1775.
Gunny
Dave, Mike likes to get me going. He should know enough about aerodynamics to know that I am right. To answer your question, yes I have flown many thousands of hours in airplanes with slats. But none of them were a Cub. What I know about Cub slats I have learned here. One thing that I have noticed is that Dakota did not change the plan form of the wing. Wayne placed his out in front of the leading edge thus increasing the chord and reducing the aspect ratio.....about the "secondary airfoil" and whether it's built into the existing one or what.........
Dakota's SLOT is part of the same airfoill. Wayne's SLAT is a separate, movable airfoil. agreed??? Yes!
Here's the muddy part........The Helio uses a movable SLAT that in cruise flight is part of the normal airfoil, but in slow flight moves forward, away from the existing airfoil, becomes independent, and leaves a kindof 'SHARP" leading edge on the 'mother' wing.
Skywagon and MTV, you guys ever fly a slat or slot??
One airplane, a DC-9-30 that I flew a lot, had the option of using the slat or not. When you did not you were suppose to add 25 knots to the approach speed. I tried it one time and got the stick shaker at +30 knots just prior to touch down. Normally one never triggers the stick shaker. So that tells me that on that airplane the slats make more than 30 knots difference in the landing speed. I might point out that a lot of the take off accidents in airliners which crashed with ice on the wings, I have noticed several, did not have slats. So I am to assume that the airflow through the slot bypassed any ice on the leading edge of the slot of the other airplanes. Perhaps this will also work the same on a CUB?
I think that Doug Keller's double slotted flaps are the best thing since sliced bread. And no I have not flown them.
N1PA
Skywagon, good point about the air through the slats "slot" did not have to contend with the leading edge icing.
68Pop, I have absolute confidence that a slat on a round tip would be very effective at giving the a/c MUCH MUCH slower and tighter maneuvering than an unslatted round tip. But I have not tried it yet. Can you use slats to help your sheep hunts???? Randy Goza..aka.."5 Rivers" must have an opinon. My opinion is that slats are fun and greatly add to the nimbleness of slow-flight maneuvering, but, unless it's 'over an obstacle' will not improve your shortest landing or takeoff until we figure out how to get a Cub to allow the available slatted-angle of attack potential to be useful AT TOUCHDOWN and LIFT OFF. There is more to be said about this, and it has very little to do with MikeO's "daddy long legs" gear.
Oleos like on the Storch but maybe improved. Watch some of the vintage Storch landing movies e.g. http://www.youtube.com/watch?v=VDcB0pSUYOI and note the attitude at touch down. AOA getting towards what the Dakota wing and SQ2 are capable of.
Stand your ground, don't fire unless fired upon, but if they mean to have a war let it begin here. - Capt. John Parker, Lexington April 19, 1775.
Gunny
I think that Doug- kase cub, solved the nose up issue, or at least improved it.
I don't know where you've been me lad, but I see you won first Prize!
Anybody flown those with slots/slats yet?
Stand your ground, don't fire unless fired upon, but if they mean to have a war let it begin here. - Capt. John Parker, Lexington April 19, 1775.
Gunny
Could your mostly stock or mod'd out super cub with Piper original or extended flaps break free from the bonds of mother Earth in the Alaska wilderness in DEEP WET snow at 38 degrees with 60 gal of 100LL, two people, survival gear, and traps on first takeoff attempt cutting the first ski tracks of the day???
Not to mention of a heaping load of snow on the skis.
A well equipped Mackey SQ2 with slats, O-375, and, you guessed it, Doug Keller Performance STOL double slotted, custom sheepherder added extended trailing edge, flaps can. And did. Another good mod was the center ski belly tank/pod for added floatation.
From 5 rivers on the 'performance flap' thread...
I don't know where you've been me lad, but I see you won first Prize!
So anybody running Wayne's slats with Doug's flaps within striking distance of WA? I'd like to fly the Dakota wing with its slots and larger (than stock) wing next to the slats and slotted flaps to compare. I think that would be interesting. Does Wayne have a set on his SQ2? MT is within striking distance...
Stand your ground, don't fire unless fired upon, but if they mean to have a war let it begin here. - Capt. John Parker, Lexington April 19, 1775.
Gunny
It is widely accepted that slats on a Tiger do little or nothing for the performance and most Tigers do not have them installed. In fact by the time you have removed the brackets, cables, conduits and the lever the weight saving will do more for the performance! You have to remember to lock them for aerobatics or you will get a terrible fright! ....... which is all why reading this is very interesting.
I have been told that the Rallye slats were a pain in the neck because rarely did they pop in and out together, meaning the pilot had to work at keeping the plane straight until slow enough that they were permanently deployed. This made approaches at speeds above the minimum unwise or difficult which reduced the flexibility of the aircraft in some circumstances.
I have wondered if the same issues apply to the Mackey style slats, but that is why the Dakota Cub slots seem more attractive to me.....
Andrew.
Nice thread here and very interesting. I've watch ed videos of many of the slotted wing airplanes and been impressed by most of them. I don't think I would like the extreme nose high landing but the Helio seems to be able to land in a much flatter plane. The moveable slats are of much interest to me but I don't like them being independent of each other. It would seem to me that a simple mechanism that would mechanically deploy the slats when the flaps are employed would be a better way. The slots are basically used when landing and coincide with the use of flaps. They could be made to work and be all the way extended at say 20degrees of flap. With them working independently on each wing I would be concerned about one being stuck while the other extened....if they work together mechanically and at the pilots behest by lowering the flaps, it would seem to be safer to me.
Does anyone know any good sources for the placement and dimensioning of any slats or slots for the Helio or any other aircraft?
For what it's worth, here's my "average-guy" impression of Mackey's slats (I've never flown the slotted wing, but would be interested to try that too.) Not only am I not a professional bush pilot, but I'm probably downright mediocre compared to a lot of the guys who have already posted on this thread. However, as much as the top-end bush pilots can benefit from the magic they can do with Mackey's slats, those guys are already doing incredible things even without slats. Accordingly, I think the overall benefit of slats is as pronounced, or even more pronounced, for guys like me--average pilots who like to fly taildraggers off-airport.
The slow flight characteristics and control authority are unparalleled by any other mod I've ever seen. Even if (like me, and the majority of other average pilots who may be reading this thread) you never shoot an ultra-nose-high approach like you see in the videos or at Valdez, the stall/spin insurance and the ability to fly, control, and land the plane at much slower speeds were revolutionary for me in my regular use.
When I fly, I tend to have a "rock bottom" speed below which I may still be flying, but I won't use aggressive control inputs close to the ground for fear of the consequences. Speaking only for myself (your mileage may vary), that rock-bottom speed became 30 mph indicated for me in PA-18s equipped with slats--meaning that I still felt comfortable using full control inputs at that speed, even at 100' AGL. I had also never experienced the sensation of levitating in an airplane until I shot a few approaches with slats in a moderate headwind. Makes you feel like you can put the plane anywhere. All of a sudden, average pilots like me find themselves comfortably, and safely, being able to do things formerly reserved only for those super sticks we see in the videos.
The only problem I can see with slats is the fact that they are experimental-only at this point. If they became certified, I can't think of many reasons why anyone would own a Super Cub without them.
My two cents.
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