42 votes

Why does the Antonov AN-225 not have any winglets?

Winglets are less effective at producing added lift than an equal-length wingspan extension. They are used on airliners when simply enlarging the wing would put the plane into a larger size class, or ...
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  • 17.6k
33 votes
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Why is it rare for small aircraft to have winglets?

I've talked to a couple of aerodynamicists, and for small aircraft when you run the numbers the improvement offered by winglets is often less than the drag penalty caused by their weight (which also ...
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31 votes
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How did this flydubai 737NG get Max winglets?

These are called Split Scimitar Winglets and they are offered as an upgrade for some existing Boeing 737 NG series aircraft: Split Scimitar Winglets are offered by APB for the 737-800 and 737-900ER ...
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  • 44k
28 votes

Would an 8% reduction in drag outweigh the weight addition from this custom CFD-tested winglet?

First off, awesome question and great investigation! This kind of let's-see-what-happens inquiry will take you far should you decide to pursue aerodynamics at an advanced level (and, of course, in ...
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27 votes

Would an 8% reduction in drag outweigh the weight addition from this custom CFD-tested winglet?

The first possibility is that that the CFD in your cad isn't as sophisticated as the software used by boeing's engineers. Which means that your design may have flaws that don't show up in your ...
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25 votes
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Why do propeller blades not have winglets?

Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficient, but when span is restricted or the maximum wing bending ...
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25 votes

Is this a wing-tip device on the A-10 "Warthog"?

The wingtip devices used in A-10 Warthogs are called drooped wingtips (also called Hoerner wingtips in some cases), which essentially increase the aspect ratio of the wing by forcing the vortices ...
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  • 98.4k
24 votes
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Is wingtip design mature?

The wingtips are a unique part of the aircraft in that they really have one job; minimize drag. Their design is easy to see, and they are a fairly recent addition to transport aircraft. Developments ...
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  • 69.7k
23 votes

Why is it rare for small aircraft to have winglets?

As others have pointed out winglets don't make much aerodynamic sense for small aircraft. The point of a winglet is basically to deflect the wingtip vortex away from the lift-producing part of the ...
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  • 67.2k
17 votes
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Why don't horizontal stabilizers have winglets?

Horizontal stabilizers don't generate as much pressure difference as the wings. Generally the stab deflections are very small in flight, and there's so much other drag during landing -- when the stab ...
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17 votes

Why is it rare for small aircraft to have winglets?

First, winglets look fancy but will not help that much in drag reduction. They were pushed less by engineers than by marketing, Boeing's in particular. They help a litte in ideal conditions, but in ...
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15 votes

Why is it rare for small aircraft to have winglets?

Many small aircraft designs are rather old and winglets were not common on airliners either when they were certified. For airliners that fly 8 or more hours a day saving a few percent on fuel quickly ...
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  • 54.1k
14 votes

Why don't horizontal stabilizers have winglets?

Short answer: In all cases these are not winglets, but fins. Winglets are worse than an equal span extension and are only used if span should not increase: for limiting the wing's root bending ...
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13 votes

Do F-4 Phantom II pilots actually fold the wings?

As several of the comments have mentioned, the F-4 have the option of folding the outermost section of their wings, as shown in the picture below. The main purpose of this was simply to save ...
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  • 3,603
12 votes
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Why do winglets reduce maneuverability (of fighter jets)?

Your observation about roll inertia is correct: Winglets add proportionally more roll inertia for their small increase in L/D, and this increase exists only for the higher range of lift coefficients. ...
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12 votes
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Why don't airliner winglets have consumer advertising on them?

Why airlines don't put third-party ads on winglets I would assume that a significant part of the answer is that it would look and feel cheap (i.e. not good for the airline's brand image.) They don't ...
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  • 18.9k
12 votes
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Why do some aircraft have pods on their wing tips?

Wingtip pods or winglets differ in installation reason from aircraft to aircraft. Here is a non exhaustive list of possible reasons: Fuel tanks Whitcomb bodies to enhance the area rule of the ...
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  • 346
12 votes

Why doesn't the 747 that is testing the GE9X have winglets?

That's because its been removed for testing. The aircraft used in for flight testing the GE-9X belongs to GE and is a modified JAL 747-400. The aircraft, a former Japan Airlines -400, was acquired ...
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  • 98.4k
11 votes

Is this a wing-tip device on the A-10 "Warthog"?

It's called a drooped wingtip. The general idea is to move the vortex away from the wing, reducing it's influence. As with all the winglet variants, opinions vary about whether or not it generates ...
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  • 6,103
11 votes
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How is drag created from wingtip vortices?

Wingtip vortices don't create drag, just as wet streets don't cause rain. Lift creation and viscosity create drag. Drag is composed of pressure drag and viscous drag, and induced drag is one part of ...
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10 votes
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Minix wingtip vortices mitigation - How does it work?

The tiny mass of air that this device can affect will in no way have the claimed effect on induced drag. This wingtip vortex pseudoscience is just bullshit. What can be observed as a vortex behind the ...
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10 votes
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Why don't airliners have rudders on the winglets?

The purpose of the rudder is to control the heading of the aircraft. It turns the aircraft by creating an aerodynamic moment about the vertical axis of the aircraft. The moment is product of the ...
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  • 74.3k
10 votes

Is this a wing-tip device on the A-10 "Warthog"?

If I add raised wingtips to one of my RC planes they significantly decrease the aileron authority, meanwhile improving the dihedral effect and the self-stabilizing tendency. But for maneuverability, ...
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  • 101
9 votes
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What is the purpose of the winglets on the Socata TB-31 Omega vertical stabilizer?

What you observe here are VHF nav antennas for a VOR receiver. This antenna design is lower drag than wire whip antennas. The antenna serves no aerodynamic purpose except to minimize its own drag ...
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  • 1,706
9 votes
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Why are downward pointing winglets more efficient?

For efficiency the orientation of winglets is not important. Best would be to stretch them out horizontally, but on a canard they do double duty as vertical tails. Things look different when ...
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9 votes
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Do F-4 Phantom II pilots actually fold the wings?

In U.S. Navy and Marine Corps F-4 Phantoms, the wing fold mechanism was controlled and powered by hydraulics, since the pilot had to fold the wings after landing for taxiing around on the deck. The ...
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9 votes

Would an 8% reduction in drag outweigh the weight addition from this custom CFD-tested winglet?

First of all great analysis! I am not expert in aerodynamics but from the little I know, aircraft are a compromise. When you design a plane you have to make shapes that are possible to manufacture, ...
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  • 1,363
9 votes
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Are the aerodynamic benefits of winglets similar for both powered airplanes and gliders?

Technically yes, but you have to consider that the benefits are weighted toward higher AOAs and lower indicated airspeeds, where the vortice flow is strong enough for the energy extraction benefit to ...
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  • 104k
8 votes

Why don't airliners have rudders on the winglets?

Short answer: Vertical tails create more yawing moment per unit of drag. Vertical tails create less adverse rolling moment for a given yawing moment. The rudder works by creating a side force, just ...
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8 votes

How is drag created from wingtip vortices?

The short answer is this: Drag is not "created from" from wingtip vortices. Says McLean, The trailing vortex sheet and the rolled-up vortex cores are often seen as the direct cause of the ...
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