Linked Questions

3
votes
2answers
8k views

How could it be possible to fully prevent wing tip vortex formation? [duplicate]

I know that winglets and swept wings are ways to reduce the vortex that are currently in use on many aircraft. Are there any aircraft design concepts out there that completely eliminate the vortex ...
3
votes
2answers
570 views

Why does this plane have vapor trails coming out of wings? [duplicate]

See this video of Birmingham strong crosswinds landings: At 2.57, there is a 737-800 landing (screen shot below). One can clearly see some vapor (?) coming out of ...
0
votes
1answer
327 views

Why do I see moisture coming from the middle of the wing as well as wingtip vortices? [duplicate]

A lot of times I see small tube like streams of visible moisture training from the middle of an airliners wing. I assume this is induced drag created by wingtip vortices, when the aircraft is heavy, ...
1
vote
0answers
213 views

How does downwash bend airflow down? How can wing-tip vortices reach the airflow in front of the wing? [duplicate]

Wing-tip vortices only start occurring when the pressure difference on the two sides of the wing starts. Wouldn't this mean that by the time the downwash from the vortices is acting on the airflow it ...
58
votes
11answers
38k views

How do wings generate lift?

Just the basic question that every aviation enthusiast must be curious about: exactly how does a wing generate lift?
47
votes
8answers
12k views

How complete is our understanding of lift?

I'm currently studying for my PPL and one of the accepted textbooks contains the following disclaimer at the end of the Principles of Flight section on lift: It is important to note that the ...
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 ...
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 ...
31
votes
6answers
6k views

Why the ground effect has such a different outcome for wings and cars?

I have some confusion concerning the ground effect. If we take two applications: Aircraft and Cars, they seem to have completely opposite effects. Aircraft From Ground effect (aerodynamics), we can ...
28
votes
5answers
16k views

How do paper airplanes create lift if their wings are flat?

Paper airplanes' wings are completely flat, unlike the droplet shaped curvature of a full sized wing. How does a flat wing generate any lift if both sides have the same air pressure?
12
votes
2answers
4k views

Can these vortices be dangerous?

There is a question related to this one right here but I'm more interested in the danger of those vortices. Are they very dangerous to cause a wake turbulence for the aircraft that comes behind this? ...
7
votes
7answers
3k views

Does an aircraft landing on a carrier increase the carrier weight before it touches down? [closed]

The same question goes for any runway, but I guess that for small aircraft carriers, one might actually be able to measure the exact point of weight increases (e.g. measure the submersion of the hull)....
11
votes
2answers
28k views

How does the raked wingtip of the Boeing 787 work?

The wing tips are very different on these airplanes. The wingtip on a Boeing 787 is a sharp triangle, while the wingtip on a Boeing 737-300 is flat. British Airways Boeing 787-8 G-ZBJC wingtip | by ...
9
votes
5answers
1k views

Can wing-tip vortices be reduced/eliminated with a rear-facing propeller near the wing-tip?

Let's say we have a propeller-driven aircraft in the pusher configuration (rear-facing propellers). If we could somehow put an engine at the wing tip (ignoring structural concerns), and maybe make the ...
11
votes
3answers
11k 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 ...
10
votes
5answers
2k views

Why do wall-to-wall airfoils in wind tunnels produce no (or infinitesimal) downwash?

There are several induced drag explanations out there saying that tip/wake vortices “come from” downwash and downwash “comes from” lift. I’m using quotes because the concept is that there are no cause ...
7
votes
2answers
1k views

Why does wake turbulence sink?

There has been a remarkable story this week of a Challenger 604 business jet being rolled after encountering the wake turbulence of an A380. A Challenger 604 at FL340 operating from Male-Abu Dhabi ...
12
votes
3answers
4k views

How are these Airbus A350s flying in formation without being affected by wake turbulence?

The first photo in this article appears to depict three Airbus A350s flying closely in tandem at approximately the same altitude. I thought that a large jetliner would leave a trail of wake ...
6
votes
3answers
3k views

How is drag created from wingtip vortices?

What is the reason for the drag due to wingtip vortices? This question is about (general) performance, but doesn't answer the drag aspect.
12
votes
2answers
5k views

How is the induced drag calculated for a wing with elliptical planform?

How is the induced drag calculated for a wing with elliptical planform ? Is this wing shape the most efficient ?
10
votes
2answers
3k views

why are there no production canard GA aircraft?

You see a lot of experimental canard GA aircraft, and their performance characteristics seem great. Why don't we see any production canard designs? EDIT For clarification. I'm asking about small ...
6
votes
2answers
3k views

Why is induced drag less on a high span wing?

I have a basic question and sorry if it is a well known fact. I understand that the induced drag is due to the tip vortices changing the effective angle of attack (downwash). I searched some ...
11
votes
2answers
1k views

How "powerful" is a wing tip vortex?

I know that aircraft generate wake turbulence and wingtip vortices, and the strength of those phenomena are related to the size of the aircraft, but how powerful are wingtip vortices in terms a non-...
8
votes
1answer
2k views

Why are aircraft designed so that the wing stalls before the tail?

I read somewhere that conventional aircraft are designed so that the main wing always stalls before the tailplane. Why is that? My concern is that if the wing stalls, suddenly the tail will push the ...
7
votes
3answers
2k views

Is induced drag caused because of the tilt of the wing backwards?

In this question: Why is induced drag less on a high span wing? In the answer it was stated that wing tip vortices do not cause induced drag. If this is the case then what causes the induced drag. ...
6
votes
2answers
1k views

Why there is no wake turbulence right after touch down or before rotation?

It is said that wake turbulence occurs when an aircraft generates lift and there is no wake turbulence after touch down or before take off. That's how we avoid wake turbulence. However, I've thought ...
11
votes
1answer
3k views

Any info on very strange wing endings on this Stemme glider?

Do you have any info on this strange wing endings used on Stemme glider? Source
8
votes
3answers
492 views

Are there areas to avoid while flying formation with a larger aircraft?

Consider a fighter jet flying formation with an airliner-size aircraft, such as during an interception or mid-air refueling. Are there areas which should be avoided by the fighter jet? I.e. are there ...
9
votes
1answer
1k views

Minix wingtip vortices mitigation - How does it work?

I stumbled upon this article: Minix wing tip device promises 6% gain in fuel efficiency for airliners. Such an economy is appealing and I must confess the design is "sexy". Could someone expand a ...
4
votes
1answer
2k views

What are the pros and cons of a lift fan versus a helicopter?

F-35 uses lift fan which can create 20,000 lbs (9 tonnes) of lift in a small compact platform. I can see three or four of such lift fans that could lift a heavier plane and is seems better than a ...

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