Wingletted 767...

I don't care for it. Then again, could be worse. At one point AA was trying to entertain the idea of putting winglets on some MD-80s for routes like ORD/STL-SFO. Yikes.
 
Maximillian_Jenius said:
...lipstick on a pig! Why are winglets suddenely the "new hotness?"
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You might do a bit of research, Max. True, some devices are 'pretendlets' there mostly for looks but Aviation Partners has developed specific winglets for a number of aircraft and fuel savings are, according to different sources, above 7%.

FWIW, the concept of winglets came before the Wright brothers flew. It was just that the application and technology of the time caused more drag and carried more weight than savings provided. Not so anymore.

First app was in the 60-70s when the USAF bailed a KC-135 to NASA and found considerable savings. But it was engines or winglets and the USAF went with winglets. NASA also bailed a Continental DC-10 and produced similar findings but the airplane would have to go through recert. Not worth it.

FWIW, the same guy who came up with area ruling was pondering one day. Whitcomb set aside time every day to just THINK. He hit upon the idea and went back and found early research and built on it.

First winglets showed up on the Longhorns, the Lear 28 and 29 and that was 30 years ago.

So, not the latest hottie by any measure, Max. And certainly not lipstick on a pig when you save 7%.


http://www.aviationpartners.com/blendedwinglets.html

http://oea.larc.nasa.gov/PAIS/Concept2Reality/winglets.html
 
I do have to say the 747-200 and the 747-400 have way different techniques in landing (for me) with the same fuselage, same dimensions. How much the winglets have to do with it? I'm not sure, but the penalty for one missing is huge.

It's funny that the "latest and greatest" wings by Boeing on the 787 and 747-8 don't have winglets, but have a shape at the end that looks like a horizontal winglet.

Granted these wings were designed with CFD, and aren't a more traditional wing design.
 
ChasenSFO said:
I don't care for it. Then again, could be worse. At one point AA was trying to entertain the idea of putting winglets on some MD-80s for routes like ORD/STL-SFO. Yikes.
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Don't remember any MD-80s being modified but certainly the 727 was fitted with winglets. The problem was that while it produced benefits, the mighty tri-motor was nearing the end of its life in airline fleets. Time to recoup costs was not worth it.

Some of the winglets out there are marketing devices and not performance improvements.

Talk to the AvPartners guys and you will find it is essentially redesigning the existing wing due to the changes in the stresses on the wing and redistribution of loads. Not just a stick-0n
 
Isn't the AvPartners winglet more of a "wing sail" than a winglet? I've read their literature and understand what it does.

It seems like most early winglets were more like a fence to cut down on the drag at the wingtip.
 
Polar742 said:
I do have to say the 747-200 and the 747-400 have way different techniques in landing (for me) with the same fuselage, same dimensions. How much the winglets have to do with it? I'm not sure, but the penalty for one missing is huge.

It's funny that the "latest and greatest" wings by Boeing on the 787 and 747-8 don't have winglets, but have a shape at the end that looks like a horizontal winglet.

Granted these wings were designed with CFD, and aren't a more traditional wing design.
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No engineer but you can tackle the vortex a number of different ways including the canted or raked wingtip. Not a bad read here.

http://en.wikipedia.org/wiki/Wingtip_device

http://www.aerospaceweb.org/question/aerodynamics/q0148.shtml

Remember too that originally the 777 was going to be offered with a folding wingtip. No one wanted the complexity and added weight.
 
Polar742 said:
Isn't the AvPartners winglet more of a "wing sail" than a winglet? I've read their literature and understand what it does.

It seems like most early winglets were more like a fence to cut down on the drag at the wingtip.
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I won't argue terms as I am just a reader/aviator like you. The original concept, before flight, was termed a wing PLATE and you find them on Indy racers. They prevent any spill-0ver. The winglets/sails do more in that they extract energy from the vortex (some engineer is going to eat my lunch on that comment) AND they act as a sail.

Of course, it could all be PFM but it works. AvPartners is experimenting with the spiroid where the wingtip folds over back to the wing. It offers even more improvements but looks weird. Given the cost of fuel, however, weird trumps $$$ op costs.
 
Orange Anchor said:
No engineer but you can tackle the vortex a number of different ways including the canted or raked wingtip. Not a bad read here.

http://en.wikipedia.org/wiki/Wingtip_device

http://www.aerospaceweb.org/question/aerodynamics/q0148.shtml

Remember too that originally the 777 was going to be offered with a folding wingtip. No one wanted the complexity and added weight.
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Thanks for the links. That'll give me something to read at work.

Orange Anchor said:
I won't argue terms as I am just a reader/aviator like you. The original concept, before flight, was termed a wing PLATE and you find them on Indy racers. They prevent any spill-0ver. The winglets/sails do more in that they extract energy from the vortex (some engineer is going to eat my lunch on that comment) AND they act as a sail.

Of course, it could all be PFM but it works. AvPartners is experimenting with the spiroid where the wingtip folds over back to the wing. It offers even more improvements but looks weird. Given the cost of fuel, however, weird trumps $$$ op costs.
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I saw a picture of that concept in a magazine (Prolly Pro Pilot, since I can't get B&C A for free :laff:). Very interesting.

As I am a large fan of Indy cars (raised close enough to the IMS distance-wise and close enough to the INDY heyday time-wise) and F1, I do listen to the aero segments closely. (As an aside, Piaggio Aero sponsors Scuderia Ferarri). This year, F1 changed the rules and took off all the parts that made an F1 car look like a 1900D, and now it's all underneath aero. It's amazing what a few teams did with that....

Very interesting subject matter that is way over my head. So, I'll just say "Thanks to the nerdery, to those of you that do CFD modeling and big math equations so I can have an extra 500 nm of range and another 1000' of altitude!!!"
 
spiroid.jpg


the spiroid.

FWIW, back in the 80s Lockheed's think tank proposed a ring-wing. The wing was an ovoid and swept. It was stiffened by the vertical fin attached at the top of the swept ring. Very interesting concept. Lighter, stronger...

scan0003-1.jpg
 
Polar742 said:
This year, F1 changed the rules and took off all the parts that made an F1 car look like a 1900D, and now it's all underneath aero. It's amazing what a few teams did with that....
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That made me laugh!
 
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