Linked Questions

44
votes
3answers
17k views

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 ...
20
votes
5answers
12k views

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 ...
25
votes
4answers
5k views

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 ...
11
votes
3answers
3k views

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.
4
votes
2answers
2k views

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? ...
8
votes
4answers
9k views

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 ...
7
votes
1answer
4k views

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 ...
29
votes
10answers
9k views

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 ...
23
votes
4answers
3k views

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 ...
5
votes
4answers
2k views

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 ...
12
votes
4answers
4k views

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 ...
57
votes
5answers
13k 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 ...
7
votes
2answers
3k views

How often are slats used on airliners?

Are slats only used when there is a short runway or on all occasions?