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 ...
31
votes
Accepted
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 ...
- 54.3k
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 ...
- 3,367
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 ...
- 27.4k
26
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 ...
- 100k
13
votes
Accepted
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. ...
- 229k
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 ...
- 3,922
12
votes
Accepted
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 ...
- 346
12
votes
Accepted
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 ...
- 229k
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 ...
- 100k
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 ...
- 6,587
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, ...
- 101
10
votes
Accepted
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 ...
- 1,746
10
votes
Accepted
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 ...
- 126k
9
votes
Accepted
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 ...
- 229k
9
votes
Accepted
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 ...
- 5,732
9
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 ...
- 3,367
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, ...
- 1,501
8
votes
Why do winglets reduce maneuverability (of fighter jets)?
The effects of winglets on the maneuverability of aircraft is not straightforward, with different effects on various maneuverability parameters.
In the simplest sense, the winglets have the effect of ...
- 100k
8
votes
Accepted
What is the purpose of these winglets on the Chinese version of the An-2?
As you said, the Y-5 and Y-5B are Chinese variants of the Antonov AN-2. The Wikipedia page gives this info on the Y-5B:
Shijiazhuang Y-5B-100 – Y-5B aircraft fitted with triple tipsails on the ...
- 36k
8
votes
Why do newer 737s use two different styles of split winglets?
Since a winglet is basically a sail generating thrust (lift with a modest forward-tilted vector) from the circulating flow around the tip, extracting beneficial energy from the circulation (the thrust ...
- 126k
7
votes
Why do some aircraft have pods on their wing tips?
Many aircraft have had fuel tanks mounted on the wing tips. These were sometimes main tanks, but often were auxiliary tanks, or even "Drop Tanks" which could be jettisoned for combat.
The tip tanks ...
- 37.5k
7
votes
Accepted
How can I get started on a winglet design for a small remote controlled aircraft?
For best results, put good flaps on the wing and forget using a winglet.
If you insist on bending the wing up at its end, just continue with the tip airfoil and select the incidence such that your ...
- 229k
7
votes
Accepted
If a winglet disconnected from an airplane mid-flight, what would be the consequences?
this actually happened to the Rutan around-the-world flight, where one winglet was shaved off against the runway pavement during the takeoff roll. the pilot then stabbed the controls to overstress the ...
- 20.7k
7
votes
Why doesn't the 747 that is testing the GE9X have winglets?
To quote from this article in Popular Mechanics,
In preparation for the flight, GE removed six-foot wing extensions from the 747 to reduce the wingspan to just over 195 feet, stiffening the wing ...
- 5,508
7
votes
Accepted
Why do newer 737s use two different styles of split winglets?
The 737NG was originally introduced with with no winglets. A company called Aviation Partners worked with Boeing to develop the "blended" winglet, originally for the NG-based BBJ (Boeing Business Jet)....
- 71.8k
7
votes
Why can’t more older 737s be retrofitted with more newer winglets?
Winglets change the spanwise loading on the wing. By increasing the effective span of the wing, lift is increased towards the tips of the wing. With more lift there, you get an increased bending ...
- 6,527
6
votes
Is this a wing-tip device on the A-10 "Warthog"?
Oh boy, you guys are obsessed with that wingtip vortex, seemingly the source of all drag. No, the reason for this wingtip shape is much simpler.
It's about the protection of the ailerons from ground ...
- 229k
6
votes
Accepted
Why has Boeing used mini winglets on the 737-200?
When originally Richard Whitcomb of NASA developed the winglets, he developed the split winglets with one above and one below as shows in image below:
The one above starts at 0.4x chord from the ...
- 908
6
votes
Accepted
Why do some airplanes have their winglets at different angles?
Winglets are symmetric, meaning they are the same shape, size and angle on both sides of the airplane. Different shapes and/or angles would mean the wings would have different aerodynamic properties, ...
- 52.9k
Only top scored, non community-wiki answers of a minimum length are eligible