Why are airplane wings (on jumbo jets) "turned up" at the end?

Question

For lack of a better word...

What do those little fins do, anyways?

Answer 1

To make the path very accurate and reduce the drag at the tips..

Answer 2

Wow. Give 747 guy best answer. knows what he`s talking about. Interesting question and good answer too

Answer 3

I believe you are talking about the spoilers or speed breaks. They help to slow down the aircraft after a landing by disrupting the airflow over the wings. The speed breaks are usually paired with the reverse thrust and of course the breaks. It takes a lot to slow down an airplane going 150 knots (170mph)

Answer 4

they are called winglets if they are turned up and wing-tip fences if they are "turned up and down"

simply,

they enhance the efficiency of the wings.

detailed they:

-decrease drag and thus increase range

-modify wake turbulence

-aesthetic appeal

-gives the aircraft a slightly higher top speed

-enhance stability

I could go into rocket science like 747guy but I'm going flying in a few minutes. just read his pretty good answer.



winglets are usually added when an existing aircraft is upgraded and requires its wings to be upgraded too. instead of lengthening the wings and strengthening them, engineers just plop winglets onto them and saves some hassle, time and money.

not only jumbo jets have winglets/wing-tip fences

its all up to the engineers and such to decide whether or not to add them for better performance

for example, boeing 737-800 -900s and 757-300 are both single aisle, 2 engined aircraft but both have winglets.

earlier 747s did not have anything on the wingtips.

the double decker A380 has wing-tip fences.

Answer 5

they were fitted after observing the tip feathers on eagles wings.  They reduce tip vortex drag dramatically, thus saving fuel.

Answer 6

makes for better air flow over wings and saves money on fuel

Answer 7

First the fins are called Winglets.  There has been years of study into their design. The French were especially active prior to WW2. The principle idea is to gain a little efficiency from the spanwise flow. This is airflow out from the wing toward the wing tip and then inward on the bottom of the wing. As you probably know there is a high pressure region under the wing and a low pressure region over the wing. (basic aerodynamics). Air will try to move from the high pressure region to the low pressure region, it cannot go forward and around the aft edge of the wing there is a small amount of forward flow at high angles of attack but the high pressure air cannot get there that way either.  But the air can flow from the root area to the tip and over to the high pressure region. This the cause of wing tip vortices.  There is a lot of energy lost from this flow and the winglets properly designed will recover some of this loss. These were some times referred to as fences in the past, which better described their function.  The effect is very similar to a longer wing without the higher bending moments that can require a much stronger wing especially at the root due to higher bending moments. This is translated into lower fuel flows at a given airspeed or a slightly higher speed at the same fuel flow.

Answer 8

IT HAS NOTHING TO DO WITH FUEL OR SAVING ANY THING ITS FOR CUTTING EGDE TO MAKE THE PLANE RIDE MORE STABLE AND SMOOTH

Answer 9

Little fins are correctly called winglets.

Winglets are used on commercial aircraft because they are a means of reducing drag without increasing the wing span.

Adding span is generally better, but there are aerodynamic and structural considerations which make winglets more attractive, especially in light of current technologies.

It is acting as a fence to keep the high pressure air on the bottom side of the wing from mixing with the low pressure air on top of the wing.

The cost savings on fuel makes it an attractive addition, however the style and engineering of the wing have to be considered before the extra fin is added or all they will be adding is weight and drag.

Besides that they make great adverising areas for the passengers.