Why don't all new jets have winglets?
 

Why do I only see some aircraft with winglets? Do they only benefit certain wing designs?

They benefit all wings as the best wing is a tube. But there may be structural concerns at the ends.

So that's what they're called...

With the exception of the 737, on which they absolutely look ridiculous, they definetely look cool..
This was taken leaving Buffalo, with Niagara Falls in the background..

oops, heres the pic..


http://forums.pelicanparts.com/uploa...1165369539.jpg

Depending on the design (strictly from an engineering and not an aesthetic perspective here) the aerodynamic benefits of eliminating or reducing spanwise flow might be offset by the additional weight of the winglets, the structure needed to support them, or both. The whole design picture needs to be considered (which I'm sure it is).

Yea, but those huge blended winglets on the 737NG's are actually the most efficient versions in existence. Beauty does not factor into the equation when it comes to airliner economics - just look at the A-380, probably the ugliest airliner I've ever seen, but probably the most efficient also.

Are you sure about that? What about an elliptical wing? ( http://en.wikipedia.org/wiki/Elliptical_wing ) :cool:

Re: Why don't all new jets have winglets?
 

Oh yeah . . the original Q... Cost.

... like replacing the P&C's on your 911 w/ higher compression ratio versions . .. you'll get better mpg & performance . .. but at what cost? Old planes, like old 911s (pre-SC):cool: just may be headed for the scrap heap soon. Thus they don't get the upgrade.

737 winglets only weigh 200 lbs. I've changed a few out. They must really do something for fuel economy since SWA is installing them on our older 737-300's beginning in Jan. Biggest drawback from my perspective is that they are lightning rods. They have no static wicks and lightning strikes typically blow out the trailing edges.

im sure on the 737s are quite worth it, but they are still ugly,.. That picture above doesnt show it that good. They stick up way above the body!

Scott, Im allowed to say so, because my plane has winglets, yours doesnt.. ;)

Form follows function.

Re: Re: Why don't all new jets have winglets?
 

island's right. Cost. We actually quoted building these here at our facility (Boeing) to retrofit onto older planes. It's being done (not here - we were too expensive), but it all boils down to cost.

Mike

The reason why spells: certification

Adding winglets to existing designs means that whole aircraft family would need to be re-certified, which isn't quite cheap och easy to do.

With other words, even if you can save 4% on fuel on a 737-100 or such old bird, expenses would be eaten up by gigantic costs of re-certification + additional work to install winglets.

Aircraft industry isn't car industry. You can have the mother of all smart solutions that could save you heaps of dollars in your hands, but you aren't allowed to put it on the plane as long as AC is certified without it.

Winglets can be rolled into an STC (secondary type certification). It's essentially an approved modification. Still has to be certified, but only the winglet and other affected structures/systems, not the entire aircraft.

I would suspect that beyond cost, in many cases they aren't installed because you hit the point of diminishing returns. If the drag reduction from the winglet is insignificant compared to the drag polar (entire aircraft), then the additional weight/cost/complexity wouldn't be justified. Part of the reason most smaller aircraft don't have them, the contribution to overall drag by the tip vorticies isn't that large. In an otherwise efficient design, they can make a very noticable difference.

Plus, releasing winglets on a new "improved" model of an aircraft can be a selling point. Just like sticking a more powerful engine in a car, aircraft companies upgrade their aircraft periodically to make them more appealing. I work at Raytheon Aircraft, several of our new Hawker jet and Beechcraft King Air models feature winglets. They're not all new aircraft, just derivatives of an existing one, so a much smaller investment by the company.

OWP,

Do you know anything about the Raytheon jobs up in Antarctica? A friend of mine wants to go up there for the "winter term"

Here is a better picture. Winglets are cool.

http://forums.pelicanparts.com/uploa...1165414137.jpg

I forgot how many pics of winglets I have. This is the last one, I promise.

http://forums.pelicanparts.com/uploa...1165414295.jpg

"Up in Antarctica"!??!!? Where in the hell are you now? :>)

Just kidding...

Mike

Antarctica?! That sounds like a choice gig. I don't know anything about it, but I'm part of Raytheon Aircraft. We're kind of the red-headed stepchild of the Raytheon family, we're the only part that has very little involvement with the defense industry (except the T-6A trainer). Being a commercial aviation manufacturer makes us a bit different, which is probably why we're for sale. Now that the aircraft I've been working on (Hawker 4000) is certified, I expect our company to be sold before the end of the year. Rumored price is about 3 billion.:eek:

IMHO winglets are the best thing that's happened to 737s. They make it look modern to me. I always thought before that they looked like ME-262s - the first German jet planes and anything but new.....

One of the guys at my forum is in antarctica as we speak(He's an IT guy).

Better him than me i says.

PS: Antarctica is 'down there'. ;)

This reminds me of a story recently... which leads me to a question for you air experts.

I was on a SwissAir flight from Zurich to Belgrade, an A319 with winglets, we had boarded and were at the hanger. We started to get backed up from the loading dock and "Crunch!" we feel the plane hit something and the plane stops.

A few minutes later, the German accented pilot comes on the intercom and he is obviously upset. He said that there was a problem and the plane had been backed into the caterring truck, causing damage to the wing. He tells us that we would be switching to another plane in a few minutes...

So we wait about 40 minutes and everyone is wondering what is going on. We look outside the window of the plane and see that the Winglet was crushed and was hanging partially down from the wing. It had been hit by the catering truck and was beyond repair (apparently).

They started unloading the luggage from the plane but we were all just sitting there waiting. I had been flying for over 24 straight hours from LA to my final destination in Serbia. (hopefully)

After 40 minutes, the Pilot comes back on and says "ladies and gentlemen there has been a change, we are not going on to a new plane, instead we will fix this plane and fly off...so please remain seated while we repair this plane"

That announcement really upset some people. This one guy was freaking out "Im not flying on a plane with a damaged wing!" he starts shouting... The purser comes back and started arguing with the passenger that it was safe and after the repair everything was going to be ok. The passenger didnt believe him and other people started chiming in agreeing with the passenger that they didnt want to fly on this plane either.

An international incident was brewing.

The pilot then came out of the cockpit and comes down the isle. He was upset and starts arguing with the passengers too. All of this was happening while the plane still had not been repaired. The mechanics had removed the Winglet... but a new one had not been brought up to repair it yet. This was about 2 hours after we had been scheduled to depart.

At that point, I had had enough of SwissAir... the repair had not been started yet, the crew and pilot were rude and arguing with the passengers and I had not slept in 2 days wearing the same clothes and underwear for 2 days.

Some other passengers started saying that they wanted to get off the plane, so I raised my hand (due to the circumstances) and asked to get off as well. We were escorted from the plane and back to the terminal where we rebooked flights the next day. Swiss Air lost one of my bags, I was escorted to a train to Winterthur, where I stayed in a hotel overnight... Switzerland is a beautiful country by the way..

Anyway, to make a long story short, the plane apparently didnt crash after the repair was finally made, but I didnt reget getting off that plane because I was tired and it was getting surreallly ridiculous with Swiss Air...

So, would a damaged Winglet have put the flight in jeopardy? One of the other passengers said that the wing could have developed cracks in it after the collision with the catering truck... was this possible?

In the pic below, the Airbus 319 has a much smaller winglet, perhaps its more of a wing-cap than an actual winglet... this was the part that was damaged. (note the catering truck to the rear of the plane)

http://www.jetphotos.net/images/0/022_19.JPG.94494

Whats the difference between a cunard and a winglet? BY the way if you think the winglets look ugly on the SWA jets the paint looks worse IMO. No offense and I am flying SWA this weekend to Fla.

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

Basically a horizontal stabilizer, but stuck on the front of the plane. Picture the Beech Starship (or Google it). Can make for a very manuverable and efficient plane, but can also present stability problems. If you know what a Burt Rutan aircraft looks like, you know what a canard is.

Damage purely to the winglet probably didn't do any additional harm. They're often composite, so they'll give long before they are able to do damage to the main wing's aluminum structure. An actual impact to the wing itself would be more troubling.

Ty

Interesting story! I don't know what's wrong with Swiss crews...few weeks ago Swiss MX-crowd taxied an A340 w/o closing pax door, tearing it off!

http://www1.airliners.net/discussions/general_aviation/read.main/3120574/

BTW, what did you do in Belgrade? :-)

This has nothing to do with SW, but the 737 itself. Sorry, the winglets are just butt-ugly. The 747-400 and big Airbus has some cool slanted ones, but the RJs look the best..

Goran... wow, thats an interesting story about Swiss damaging the plane. The incident to my plane took place on Sept. 19th.

The Zurich airport, is very modern and is really great... but the Swiss crew generally seemed disorganized and rude, really. At the end of the incident, the 2nd shift Swiss station manager took good care of me and was very helpful in locating my lost bag, and one of the girls in reservations helped me find a local hotel....but the rest of them were pretty bad.

Are you from Serbia?

I have business associates there. I use the services of a studio there for my company (advertising & marketing). I had a great time there and I plan to go back this spring to see more of the city. The people were very accomodating, yet have a very strong spirit and somewhat defiant attitude, which is great. I found Belgrade to be a bustling, busy city full of life.

Nope, I'm born in Bosnia. My mom is from Belgrade and I still have relatives there. Unfortunately, I haven't visited Belgrade since late 80's. It would be great fun to visit it again, altough I am probably too de-balkanised at this stage to enjoy it in any other way but as a tourist :)

Well now I hope you have an enjoyable flight.
And it's canard not cunard.:D

You are gonna laugh at this one. The Gulfstreams were one of the first bizjets to certify with winglets. The FAA required it to be flown with one missing. Competely gone.

Slight roll (1/4 aileron to compensate) was all.

No big deal.

I don't doubt it in the least. I've been working in the flight test program for the last couple months, it's incredible the stuff required for cert.

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Cool site on the topic of winglets, by Boeing.

http://www.aviationpartnersboeing.com/

Careful now...some of us may have designed portions of those winglets. ;)

Am I the only one who thinks it odd that anyone would think that winglets are some sort of styling exercise?

You know they are.:D
http://www.evworld.com/images/cadillac_fins.jpg