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Certificated to experimental for leading edge cuffs

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blane.c

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I am prejudice to the Sportsman stall cuffs, They are stc'd to Cessna but some were also designed for Piper and not stc'd (to my knowledge) so if the airfoil is the same to one of those or very similar they may work.
 

wktaylor

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This was FUN...!!!

NOTE.
From 1979-to-1980 I worked at Piper Aerostar as a production Liaison Engineer. What a great 'starter job'!!!
In the Mid 1980s I was The USAF Lead structures/mechanical Engineer for the A-37B and T-37B [SA TX]. One afternoon I got a call from a guy who wanted info on the 'stall strakes' on each side of the '37 nose [doors]. Found out he wanted info to improve slow speed controllability of the 'bare/long-nose Aerostar'... sorta like the prototype '37 wide-nose without strakes'... that had controllability/spin recovery issues [prototype was lost in a unrecoverable spin]. I remember spontaneously laughing-hysterically and said... 'he just happened to call the ONE guy in DoD who had a few clue-cards about the Aerostar.' We corresponded a bit... then I lost track of Him. A few years later there was a slow speed controllability mod-Kit available for the Aerostar... which included [oddly] included a single-side nose strake plus vortex generators and some other-stuff. Unsure if it is still on the market or available only thru the Aerostar Owners Association [etc]
Aerostar Owners Association .

Related to Mooney... A peek-at/discussion-with others about their aerodynamics mods may be a real eye-opener!

AOPA 1997 article Modding Mooneys Modding Mooneys Exploring the Mooney upgrade market
Modding Mooneys

LASAR Mods Mooney Speed Modifications - Lake Aero Styling & Repair — LASAR

Knots2U Speed Mods Mooney Speed Mods from Knots 2U

and cool...!!!
MooneySpace Mooneyspace.com - A community for Mooney aircraft owners and enthusiasts

EMAPA Mooney Cowl Kit, LoPresti aviation, Aircraft Lighting, EMAPA, Aircraft Lights
 

blane.c

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In actuality stall strips may be more beneficial because the down side of stall cuffs is sometimes the whole wing quits flying at a low airspeed in relation to normal airspeed and aileron control is usually the first of the (3) control inputs to go first so loss or reduced aileron control in conjunction with the stall can make recovery more difficult or impossible. I knew and used to fly with an old pilot who had stall cuffs on his 180 but stall strips on his (highly modified with Continental O-470) Navion.

Stall Strips: How They Work
 

edwisch

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When all is said and done, VGs will be your best bet... but some good theoretical analysis of airfoils will be a good learning exercise no matter what you decide in the end. A few knots difference in cruise between VGs and cuffs will, in my opinion, be pretty much a so what. Another option is to get with a good CFI and really explore the low speed handling of the Mooney so that you can get the most out of it. If you get VGs or cuffs, you'll want to do that anyway. I've got some low speed exercises that two well-qualified Mooney pilots liked but the Mooney PPP folks don't want anything new...
 

wktaylor

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Some Fud-4-Thot...


NOT much talk about STOL mods for Mooneys!? Lots of talk-about making Mooneys go FASTER!

BTW... There may be some Mooney-specific flight instructors that can help You be safer [more aware/vigilant] at lower airspeeds.
 

Victor Bravo

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Will VG's wreck the drag characteristics of a Mooney airfoil? I am not that familiar with Mooneys, and I have no idea whether they use "laminar" sections or not.
 

TFF

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It’s been a while but I always thought the Mooney slowed pretty good. I always thought the flare was more 172 ish compared to an AA5 which always seemed a little hotter in the flare. Nailing it so it didn’t float was the hard part. I have never gotten to fly one but a Bellanca, especially early ones will land slow.
 

Petehdgs

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You all have been a big help. I now have a copy of designfoil and will take a look at the GA airfoil, 6x, and a GA-6x combo to see if there is anything worth pursuing first. I admit it might not be worth the time, but you never know until you look.
One Miracle at a time!

Thank you all.
 

Petehdgs

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So I ran a quick test on the 63-215 airfoil and compared it to the published data and am really disappointed. The sharp stall apparent in the published data is no where near duplicated with any accuracy at all. That means I can't make decisions based on reliable data. Unless something changes I am out.
 

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proppastie

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you land the Mooney like Goldilocks ......not too hot and not too cold and it lands fine......I will admit it does not like to fly slow.....somewhat piggy (technical term there) little slow to respond which is probably better than twitchy....too fast and you can float off the end of the runway and you do not want to let any aircraft get too slow. All design is compromise and the Mooney is a go places aircraft, a solid IFR platform and not a training aircraft.
 

Pops

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I few my Falconar F-12 for several years with a very sharp stall, no warning, instant nose drop down and would spin very easy in either direction. The reason I carried about 95-100 mph in the pattern with shallow turns. Then down to 80 mph if light and 85 mph with someone in the right seat.
Falconar came out with a notice to install stall strips to help the stall. Just about 8" long triangle stall strip about 2' out from the side of the fuselage. Couldn't believe the difference, the stall was about like a Piper Cherokee. But, there was a price. The ROC was down from 1700 FPM at GW to about 1500 FPM at GW.
Takeoff roll was a little longer.

Never was a Mooney lover, like the Bellanca Viking better.
 

Hephaestus

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Offer a mod to get 2-3kts - you'll sell thousands.

STOL kit? I think there's a guy or two up in alaska who might be interested... but I think they want bigger tires over slower approaches.
 

Petehdgs

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Offer a mod to get 2-3kts - you'll sell thousands.

STOL kit? I think there's a guy or two up in alaska who might be interested... but I think they want bigger tires over slower approaches.
I appreciate your thought on this, but the numbers I came up with are a little lower. There were about 7000 180 & 200 HP Mooneys made, about 5000 of those are short body Cs & Es. 1% of that is 50-70 units. That would be the number who would find value in a soft stall and speed reduction on landing, and that could pay for the cost involved in development and production. My initial thinking on this was the value wasn't so much in a speed reduction, but a forgiveness of the stall that allows you to get as slow as possible and hang there while you land.

So I guess I am naieve but I really thought a computer simulator would show the change in the stall if the leading edge was modified. I looked up the Abbot & Doenhoff 63-215 for the first time in several years. I was surprised at how hard the stall is, especially with full flaps, but it is pretty hard without flaps too. The interesting part is I can feel the difference with no flaps, partial flaps, and full flaps! The curves are not that different, yet I find my bird much easier to land smoothly with 1/2-2/3 flaps or no flaps than full flaps. Imagine how smooth all the landings would be if I could stretch out the top of the stall curve by 2-3 degrees AOA.

When I pulled up the same airfoil on Designfoil, the stall curve was smooth and elongated, just like I want. That is not realistic for that airfoil and tells me the computer simulation is of no use to me. The problem going forward is it calls into question Harry Riblett's claim that his suggested modifications will work as intended. He obviously knew a lot more about airfoils than I do, but going forward it seems like a lot of effort to put out on the belief that this modification will perform as intended.

So I am at an impasse.
 

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Dana

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One thing to remember about the Abbot & Doenhoff data is that it's 2D data, no consideration of the actual wing planform, and the flap they tested is a split flap, which is rarely used in the real world. It predicts a sharp stall for the 230xx series too, but you'd never know it from flying a Taylorcraft (which uses a 23012).

I don't know how Designfoil works, but most computer simulations have a hard time when the flow becomes separated and chaotic, it may be making some assumptions to smooth the data.
 

BBerson

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2 or 3 degrees AOA won't have much effect. The NASA cuffs add about 10-15° AOA (30° total).
Not much use for touchdown if the landing gear can't accommodate 30°.
But the cuffs do prevent stall and spins at altitude.
 
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BJC

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I find my bird much easier to land smoothly with 1/2-2/3 flaps or no flaps than full flaps.
How much of that is due to the need for better, faster, control input in the flair because of the greater drag / faster deceleration with full flaps? A PA -18 three points easily with partial flap deployment, even for someone who doesn’t regularly fly the Super Cub. With full flaps, timing is everything.


BJC
 

TFF

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No aircraft is crisp handling with flaps that work. They work very well on a Mooney. My point on the Grumman is the flaps suck relatively. They are not very effective. They do something, but they are the same size as the ailerons. Ailerons are pretty decent on a Grumman. Full flaps is for generating lift at gross weight; the original need. It does help steepen the usable glide path unless you own a Grumman, which still lands flat as a board. The Mooney in my opinion is the best bang for the buck people mover, on the C-F spectrum; the Gis a strange one. Without throwing your best three friends in, it’s got more flaps than needed at just a pilot flying around.
 
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