Linked Questions

58 votes
6 answers

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 ...
Peter Kämpf's user avatar
30 votes
10 answers

What is ground effect?

We've all heard the "acts like a cushion of air" explanation tossed casually around by CFIs. There's also plenty of books and reference materials that give a detailed, accurate, and complete ...
Steve V.'s user avatar
  • 23.1k
48 votes
3 answers

Why does supersonic flight detach airflow from a wing?

I've read in several answers to questions that when a wing passes the speed of sound the airflow will become detached from the craft towards the rear quarter of the wing (thus making things like ...
Jae Carr's user avatar
  • 24k
24 votes
4 answers

Why are heavy flaps better than just a bigger wing?

Flaps increase lift during landing and T/O. But when retracted, they do nothing. The space needed to stow the common fowler flaps can't be used for anything else - fuel or structure. Extended flaps ...
Abdullah's user avatar
  • 3,524
23 votes
4 answers

Would an aircraft with contra-rotating propellers longer than the plane's wingspan be able to fly?

I enjoy taking the time to try and visualize how fictional aircraft might actually work in reality. Unfortunately there are some that seem highly impractical from an engineering student's point of ...
Kyle Lowery's user avatar
20 votes
5 answers

What are the advantages of a Trimmable Horizontal Stabilizer?

What are the advantages of a Trimmable Horizontal Stabilizer (THS)? For example, a THS is used on some Airbus and Embraer aircraft. What is the most important advantage, and why don't some other ...
user13197's user avatar
  • 11.4k
12 votes
4 answers

Why isn't there a single best airfoil for subsonic flight?

Why does airfoil used by modern subsonic aircraft (this is true for transonic airliners too) vary from plane to plane? Haven't we figured out a single best airfoil shape, with the highest lift to ...
Francis L.'s user avatar
  • 2,484
13 votes
3 answers

Does static longitudinal stability require download on the tail?

After having encountered this meme too often for comfort, I ask myself today in order to have the possibility to explain the issue in detail.
Peter Kämpf's user avatar
11 votes
3 answers

How does the slotted flap work?

Slotted flap is an improved version of the plain flap, generating more lift (a fact I don't challenge). However the principle is air passing between the wing and the flap. Source This seems ...
mins's user avatar
  • 70.9k
4 votes
2 answers

Why are highly cambered airfoils rarely used in propellers or wings?

Highly cambered airfoils like the Seligs and Epplers are hardly ever used in propeller or wing sections. Why? Does their performance reduce at high Re? Are they only adequate at low Mach, low Re? ...
toshi ba's user avatar
  • 411
7 votes
2 answers

How often are slats used on airliners?

Are slats only used when there is a short runway or on all occasions?
tainehu's user avatar
  • 197
5 votes
4 answers

Can this design provide more lift force than thrust from engine?

The problem is depicted in the picture: Generally, why we don't use engine blow wings to fly? Can we use wind-tunnel-like wing to generate lift force? Can it generate more lift than thrust? If it ...
Libo Liu's user avatar
7 votes
1 answer

How can we determine the maximum camber and thickness for airplane wings?

I want to know if there are any standard factors for determining maximum wing camber and thickness for heavy and light airplanes? I'm using an optimization process to find the best wing shape to ...
user14747's user avatar
5 votes
3 answers

Why have high lift devices on both leading and trailing edge?

Trailing edge devices such as flaps increase lift by raising lift coefficient at s given AoA. Leading edge devices such as slats increase lift by raising stall AoA. The former is nice because it ...
Abdullah's user avatar
  • 3,524
2 votes
3 answers

How does increasing camber increase lift coefficient?

How does increasing the camber of an airfoil (like the NACA 0018) increase its coefficient of lift? You're just curving the airfoil; I don't see how that increases lift for a given angle of attack?
MichaelK's user avatar