Linked Questions

2
votes
1answer
72 views

What is the Relation between Critical AoA with Chordline? [duplicate]

I read here an explanation about angle of attack (AoA) as below: Overly long (forward-back wise) wings will generally have a smaller critical Angle of Attack while smaller ones will have more ...
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 ...
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 ...
19
votes
3answers
26k views

What is the purpose of a dorsal fin such as on the Boeing 737?

I've noticed that the 737 has a rather unusual vertical stabilizer, with an extension at the front. Is the 737 the only plane equipped with such a vertical stabilizer, and what is its purpose?
22
votes
3answers
18k views

What dictates the aspect ratio of an aircraft's wing?

When designing an aircraft, there has to be a decision as to the aspect ratio of a wing. It's been said that having a higher aspect wing will reduce drag for the same wing area, however most of the ...
18
votes
2answers
7k views

Why do some airplanes have vertical strakes?

A lot of different aircraft have vertical or near-vertical fins below the empennage, or above the empennage and attached to the front of the vertical stabilizer. What purpose do these devices serve?
15
votes
3answers
4k views

What are the disadvantages of a delta wing biplane design?

The idea of a delta wing as I understand it is to reduce stress on the wing and drag on the leading edge. Now using two delta wings on separate planes, on one frame would presumably allow for a ...
15
votes
3answers
3k views

Do some light sport aircraft have clipped wings to lower their cruise speed?

Light sport aircraft may have a max airspeed in level flight at MCP of 120kts. I have heard that there are some light sport aircraft that have had their wings clipped in order to have a lower cruise ...
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 ...
15
votes
3answers
3k views

How would an Inverted Delta Wing planform behave, Straight part forward? Are there wings shaped this way?

There is info about straight edge wings, swept back wings, swept forward wings, delta wings. Is there also info about a Delta wing with a straight leading edge and a tapered trailing edge, the point ...
4
votes
3answers
16k views

How does the aspect ratio of a wing impact its lift?

The wing lift formula shows that lift of a wing is proportional to its area. $ L = {\dfrac 1 2 \times \rho V^2 \color{magenta}S C_L} {\small \begin{align} &{} &&\text{where:} &&L =...
9
votes
5answers
912 views

Do most commercial jets have a negative lifting body?

I took a look at some example airfoils and noticed they all seem to have a downward hook at the end. I believe this draws the air downwards, creating a reaction force upwards: lift. Now here is a ...
5
votes
4answers
1k views

What is the fundamental physics behind L/D decreasing as AoA increases beyond the optimal point?

Why does lift over drag decrease with AoA past the optimum AoA? Is it because the backwards vector for a given lift force on the wing is now larger for a given air particle compared to lower AoA? ...
9
votes
1answer
5k views

How can I calculate the rolling moment of an aileron for a given plane based on its performance?

Let's say I have an already-built airplane with known basic characteristics like weight, wing span and wing surface, and I can measure the time of all possible manoeuvres at different speeds. How ...
6
votes
2answers
2k views

Is there a parameter that links the areas of the fuselage and control surfaces? [closed]

Do aircraft designers look at the ratio of how much fuselage surface area can be loaded onto a given unit of wing and tail surface area including elevator, aileron, rudder etc? (Possibly, the surfaces ...

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