Modern Winglets

[Chris K]

Most of you may know that the recent Acclaim/Ultra renditions from Mooney had additional aerodynamic touches to fill more gaps in the airframe, a composite (cleaner) forward cabin and newer winglets.  Out of curiosity I started looking into what sort of efficiency the newer winglets provide and could not find anything online - has anyone actually seen any sort of testing or information published?  

Separately, I did come across this winglet (link below) which look like the Ultra winglets on steriods as these seem to trail several inches further back than the ailerons.  I also found a picture with these winglets on N252AD online.  Not sure if the owner is on here or not, but wondering what his feedback on this product is or whether anyone else on here has tried these.  Seemingly if these are efficient, you'd get both the LED light conversion along with a more efficient wing?

https://www.aveoengineering.com/crystal-conforma-for-mooney/

[DanM20C]

Just now, Chris K said:

Not sure if the owner is on here or not, but wondering what his feedback on this product

@gsxrpilot is the man!

I think Paul reported not noticing much performance change. They look awesome though

cheers,

Dan

[gsxrpilot]

Yeah, I put them on to soon in the ownership of 252AD so I don't know if they made any improvement in performance. I like the look of them and they include the LED Nav and Strobe lights. 

They don't extend past the aileron but are flush with the trailing edge.

[carusoam]

One thing for sure...

They show how nicely LEDs can be precision integrated into a smooth fiberglass shaped wing tip...
 

That is a nice touch...

Aveo visited Mooney Summit and gave a presentation on their lighting equipment...

Could be a fuzzy memory... it’s been a while.

Best regards,

-a-

[FLYFST]

Be very CAREFUL and make sure there is an approved STC for this installation on the aircraft in question.  Winglets change the load distribution on the wing, how much depends on the winglet design and the wing in question, and can result in unexpected problems, possibly severe.  The installation without an approved STC can invalidate the aircraft's airworthiness certificate and for very good reasons.  The ones referenced do look very nice -- Caveat Emptor

[aviatoreb]

11 hours ago, gsxrpilot said:

Yeah, I put them on to soon in the ownership of 252AD so I don't know if they made any improvement in performance. I like the look of them and they include the LED Nav and Strobe lights. 

They don't extend past the aileron but are flush with the trailing edge.

They look great.  I wish there were some before and after install flight tests.

[gsxrpilot]

1 hour ago, aviatoreb said:

They look great.  I wish there were some before and after install flight tests.

What, the good looks aren't enough? 

[Seth]

11 hours ago, carusoam said:

One thing for sure...

They show how nicely LEDs can be precision integrated into a smooth fiberglass shaped wing tip...
 

That is a nice touch...

Aveo visited Mooney Summit and gave a presentation on their lighting equipment...

Could be a fuzzy memory... it’s been a while.

Best regards,

-a-

Correct - Aveo was there and showed them off. If anyone would like I can put you in touch with my contact at their shop in Florida for further information. They have been a nice sponsor of Mooney Summit giving a pair of wintipe nav strobes the last few years for the silent auction. They plan to be present when Mooney Summit occurs again in 2021.

-Seth

[aviatoreb]

32 minutes ago, gsxrpilot said:

What, the good looks aren't enough? 

You know darling - its not how you feel - its how you look....and you look MAHVEHLIS!

 

Edited July 20, 2020 by aviatoreb

[PT20J]

Question: When Roy Lopresti was looking for the easiest changes to decrease drag and get to 200+ MPH on 200 hp, why did he not change Al Mooney's squared off wing tips?

Perhaps @Blue on Top could enlighten us on the efficacy and theory behind various wing tip treatments.

Skip

 

[MooneyMitch]

Per my interview of Bill Wheat during filming Boots documentary, the only part Roy created was the winglet.

 All drag reducing parts Roy directed to be implemented on the  J model had already been created and tested individually by Mooney engineers and factory workers.

Bill explained that the winglets were not necessarily a drag reduction component as much as they provided more air flow back on the ailerons creating more effectiveness.  Bill said he initially did not believe Roy’s winglets would be effective, but after flight tests, he became a believer.

This does indeed raise the question why the winglets were not part of the early J’s.

In retrospect, I should have asked Bill.

[kortopates]

LASAR did some testing with their retrofit winglets for earlier J's and other vintage models and I believe they claimed no performance enhancement. Purely cosmetic; although their add says "1.0 mph speed improvement". But its a great opportunity IMO to use the wing tips to eliminate some antenna drag by placing the nav antenna's in them - something I've done and something LASAR also offered with their kit as well. Boost that speed enhancement to at least 3 mph! 

[Blue on Top]

30 minutes ago, PT20J said:

Perhaps @Blue on Top could enlighten us on the efficacy and theory behind various wing tip treatments.

So, I'll be as PC as possible as I am currently re-reading "How to Win Friends and Influence People" (but I am an engineer).  They look good.

Burying lights and antennas is always good ... for drag reduction.  Their website says that they are for the M20J, M20K, M20 L and M20S, which is a really strange combination (reason shortly).  The website also states that they are NOT certificated yet.

As for simple drawbacks, if the wingtip is carbon, an antenna will not work inside the wingtip ... especially if it has a copper mesh buried in it for lightening protection.  If there is no copper mesh, they'll have to prove to the FAA that when the wingtip takes a lightening strike, nothing inside of it is critical to flight (antenna, strobe, navigation light).  But that's not aerodynamics

This  is a wingtip per FAA definition and NOT a winglet.  These actually look like wingtips on the current "Ultras".  A wingtip addition doesn't need to re-examine wing bending loads and are not considered "structural."  So, the advantages are two.  1) it slightly extends the wingspan, making it very slightly more efficient and 2) it makes the aileron more effective as less airflow will go around the end of a deflected aileron.  Aileron forces will be very slightly higher, too, as a direct result.

My questioning of the" to-be-approved models is that the "J" (and maybe the "K") has an external (end of the wing) horn balance weight that goes well forward.  This wingtip would make that balance weight pop in and out of the wing surfaces, whcih could change aileron forces.  How many "L"s exist?  Why the "S" and not all the other models?

And, specifically for @PT20J ... sorry.  A slight upsweep is actually not good.  Squared off tips are actually good.  The reason is that one wants the wingtip vortices to depart the airplane cleanly.  Any roundness will cause the vortices to cling to the airplane and be drawn inward ... slightly shortening the wingspan.

Hope this helps -Ron

 

PS. Effect of wingtips/winglets depends on the wing CL.  They always add drag, but do they reduce the overall wing drag during climb and/or high altitude cruise?

PS2.  Per the FAA, a wingtip technically doesn't rise above the wing upper surface.

-

[Skates97]

12 hours ago, Seth said:

Correct - Aveo was there and showed them off. If anyone would like I can put you in touch with my contact at their shop in Florida for further information. They have been a nice sponsor of Mooney Summit giving a pair of wintipe nav strobes the last few years for the silent auction. They plan to be present when Mooney Summit occurs again in 2021.

-Seth

I was fortunate enough to win the silent auction for them at the summit last year, I love them! 

(I bought a new tail light to finish things off) 

 

[MooneyMitch]

Just now, Skates97 said:

I was fortunate enough to win the silent auction for them at the summit last year, I love them! 

(I bought a new tail light to finish things off) 

 

Can’t miss that flashing ship on a gorgeous LA night flight! 

[carusoam]

There are a couple of wing tip designs for long bodies...

One that has the nav lights encased behind the clear PMMA window... the meltable lens.... 

The other one... has the nav lights surface mounted....

 

So the note that pertains to the Eagle... might be the wing tip missing the meltable acrylic lens...
 

PP thoughts only, not a mechanic...

Best regards,

-a-

[MooneyMitch]

1 minute ago, carusoam said:

There are a couple of wing tip designs for long bodies...

One that has the nav lights encased behind the clear PMMA window... the meltable lens.... 

The other one... has the nav lights surface mounted....

 

So the note that pertains to the Eagle... might be the wing tip missing the meltable acrylic lens...
 

PP thoughts only, not a mechanic...

Best regards,

-a-

Broke my heart when I misaligned one Ovation forward facing recognition light and warped my acrylic. 

[gsxrpilot]

19 hours ago, Blue on Top said:

The website also states that they are NOT certificated yet.

Supposedly there is a J flying around with a set on for certification and my 252 is the certification platform for the K.

19 hours ago, Blue on Top said:

My questioning of the" to-be-approved models is that the "J" (and maybe the "K") has an external (end of the wing) horn balance weight that goes well forward.  This wingtip would make that balance weight pop in and out of the wing surfaces, whcih could change aileron forces.

Negative. This was part of the testing on my 252. The balance weight stays completely within the wingtip and still has full range of motion.

[RLCarter]

I think wingtips over the stock flat end looks so much better than the flat end, I wish there was something for short bodies available..... I would even settle for a small, very small decrease in speed.... that last part might get me kicked off MS.........  

[gsxrpilot]

12 minutes ago, RLCarter said:

I think wingtips over the stock flat end looks so much better than the flat end, I wish there was something for short bodies available..... I would even settle for a small, very small decrease in speed.... that last part might get me kicked off MS.........  

I believe LASAR has wingtips that can be fit to the short bodies. I had the 201 wingtips on my M20C, N6XM. There are pictures around here somewhere.

[Hank]

11 minutes ago, gsxrpilot said:

I believe LASAR has wingtips that can be fit to the short bodies. I had the 201 wingtips on my M20C, N6XM. There are pictures around here somewhere.

Yep, I have them on my C, too. Just no good picture showing them.

[PT20J]

20 hours ago, MooneyMitch said:

Broke my heart when I misaligned one Ovation forward facing recognition light and warped my acrylic. 

Easy to replace.

[PT20J]

It’s probably easy to change the wingtips on early Js and Ks because you can buy (assuming they are available) J/K ailerons with the balance weights made for the sculpted wingtips. Earlier models never had these wingtips from the factory and there would need to be an STC to change the ailerons and wingtips. 

I think it’s clear by now that these are wingtips (aesthetically pleasing but with no significant aerodynamic advantage) and NOT winglets. Winglets (aka tip sails — which I think is a more descriptive term) do offer aerodynamic improvement (forward component of aerodynamic force offsets some induced drag of the wing) but also have structural implications.

Skip

[Blue on Top]

1 hour ago, gsxrpilot said:

The balance weight stays completely within the wingtip and still has full range of motion.

I'm guessing then there are more than one balance weight configurations.

[Blue on Top]

Winglets change the spanwise lift distribution, increasing wing/spar bending moment.  If the same vertical surface area of a winglet would be laid flat, it would be more efficient (and the wing/spar bending moments would also be higher ... and higher than a winglet).  The most efficient wing is "flat",  Winglets were originally designed to allow for a gross weight increase without having to beef up the spar or re-wing the airplane.  If airlines really wanted the highest efficiency airplanes they would have longer wings (not winglets) ... and then they would not fit at the gates.

PS.  Winglets only reduce drag at higher CLs.  So, if you want to go faster up high (think "Acclaim"), they might do good.  If you're cruising at 5-8K, you'll add drag.

Edited July 22, 2020 by Blue on Top
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