Linked Questions

56
votes
5answers
12k views

Is a winglet better than an equal span extension?

Is there indisputable evidence that a winglet improves performance over an equal span extension? Please note: I am only interested in L/D improvements. Winglets do improve roll performance, that is ...
16
votes
5answers
22k views

Why do airplanes have to retract landing gear?

Why do all the airplanes have to retract their landing gear, once they reach some specific height? Why can't they simply leave their landing gear deployed all through the flight?
19
votes
3answers
10k views

Why is the Tu-144 the only commercial airplane with canard configuration?

I understand the delta wing was chosen because of the supersonic cruise (like the Concorde), and canards were added to reduce the approach/landing speed. But canards may be used without delta wing (e....
19
votes
6answers
16k views

Do box-wings suffer from induced drag the same way as normal wings?

Most wings suffer from induced drag due to a pressure difference above and below the wing causing air to sneak around the tip, forming a vortex. There are various methods to minimize these effects, ...
11
votes
3answers
10k views

Does the downwash created by induced drag increase or decrease lift?

According to the theory I know, lift is produced by accelerating air downwards at the trailing edge (downwash). Hence, as downwash increases so does lift. Induced drag is due to vortices at the wing ...
9
votes
2answers
49k views

What are the advantages and disadvantages of a delta wing compared to a swept wing?

What advantage does a delta wing have over a swept wing with high AR for supersonic flight? And what disadvantage does a delta wing have over a swept wing with high AR for transonic flight? The ...
6
votes
3answers
1k views

Why can't planes use only flaps in the tail section instead of stabilizers?

I imagine plane having only four flaps in the back (one on top, bottom, left and right), similar to ailerons but longer and narrower. They can open from the fuselage to correct the plane's yaw or ...
5
votes
7answers
539 views

Was the adoption of conventional tailplanes as 'everyday aircraft' inevitable, or are there other designs that can be just as good?

I originally asked a variant of this on Worldbuilding.SE, but they didn't seem to like it. So I apologize if it's out of place even here. I ask, because I've been forming in my head an alternate ...
3
votes
2answers
6k views

How are empennage airfoils chosen?

Empennage airfoils are usually symmetric. What is the process behind choosing the airfoil used in the tail of the airplane? Is it related to the stability? And then how would the angle of attack of ...
4
votes
1answer
295 views

Are canards useful for ultra low flying aircraft?

In this question about canards, they are described as being useful mostly/only for supersonic configurations which are unstable at regular? speeds. But for a low power, ground hugging aircraft, ...
0
votes
1answer
1k views

Which moments are acting on a flying airplane?

I would like to ask some clarifying questions regarding the moments acting on a flying airplane. My understanding is that there are following force: Weight (pointing down and applied to the CG of ...
0
votes
0answers
277 views

How does a horizontal tailplane stabilize a cambered airfoil aircraft? [duplicate]

The picture below shows the location and movement of centre of pressure when angle of attack is increased. Consider the aircraft is trimmed at the second airfoil in the picture. Thus the horizontal ...