Here is a question for all you aerodynamic people out there..?

Question

If the wing design characteristics of designing a airplane wing acheive better fuel burns and lowering drag results in better aerodynamic platform for airplane wings, how come Boeing hasn't developed a winglet or other drag saving devices for the B777? Airbus has winglets on the majority of their products and Boeing has approved modifications to their wings on the 737-757 series to include winglets, as well as a "cranked wingtip in the 767-400 series. If these winglets or other drag reducing devices have devreased drag as well as improving fuel burns why do we not see winglets on any of the B777 airplanes?

Answer 1

Actually, Boeing 777-200LR and 777-300ER has raked wingtips.

Answer 2

Aviation Partners Boeing (APB) is an aftermarket modification company who seems to be specializing in winglet mods for Boeing. They are selling the 737, 757 and are working on the 767 one right now.

The decision to put on a winglet is purely economic. It adds weight (and therefore increases fuel burn) but reduces induced drag and fuel burn overall. The winglet itself costs something like $700,000 (!). When you compare the initial cost against the fuel savings over the life of the aircraft, it depends on the cost of fuel.

APB has become quite successful and has a long line of customers for the 737, 757 and 767 winglets.

So why doesn't the 777 have winglets right from the factory? I have heard two different theories:
1) A Boeing wing designer once told me that Boeing didn't need winglets because their wing design was that much superior to Airbus wings.....bullcrap I think, because only a couple of years later the 747-400 came out with (you guessed it)....winglets.

2) APB is making a ton of money putting on after-market winglets at a price that is higher than Boeing would charge for a winglet at the factory. Boeing owns half of APB and therefore half of the profits...you do the math.

It is just a matter of time until we see one for the 777, but I would bet that they would come from APB and not the Boeing factory!

Answer 3

There are 2 schools of thought on winglets. One says they are a marketing ploy (looks) another says they actually serve a purpose. The only thing I know for certain that everyone agrees on is that wingtip vortices are reduced.
One says a one foot tall winglet fools the wing into believing it is two feet longer and creates more lift. When you get as far out as the end of a 777 wing, two feet of additional wing would weigh less than a winglet and it's supports.
Airplanes are now modeled almost entirely by computer and the best combination is on the final product.
I say if winglets are the best things to have on a wing, why don't ALL airplanes have them?

Answer 4

They add weight. It can cost an airline many hundreds of thousands of dollars to simply buy them, even more when you consider aircraft downtime. They are another thing to go wrong. They work better with some wing designs than others. People think they look cool, and often their actual effect is over dramatized. They actually diminish takeoff performance, hence none on the 757 series. Depending on who you ask, they have varying levels of effect. A 2004 NASA study indicated that they had no performance benefits whatsoever for subsonic flight, but that they could be deployed as a marketing tool because they look cool and enable airlines to tell passengers that they are doing something about greenhouse gas emissions. On the other hand, a company that makes them, California based Proflight, claims that they can reduce fuel consumption by between 3 and 5 percent, varying by airspeed, ambient air conditions (alt. temp. wind etc).

But I agree, it would kind of look cool on the 777.

Answer 5

What is an aerodynamic person?