Linked Questions

21
votes
3answers
5k views

Why is the use of tail-down force so common?

Why is the use of tail-down force so prevalent in aircraft design? Why not use canards to avoid induced drag?
11
votes
3answers
24k 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 ...
18
votes
2answers
19k views

How does chord length affect wing design?

In comments on the answer to a question about transonic speeds and control surfaces I came across this comment and I'm having a hard time understanding it. If you increase the chord, lift goes up ...
12
votes
2answers
29k views

Why does the B777 have no winglets? Are there any drawbacks to having winglets?

I have googled and noticed that almost every Boeing 777 is not equipped with winglets. Does anybody know the reasons why Boeing did not equip B777s with winglets? Are there any drawbacks to having ...
13
votes
2answers
22k views

What is the method to calculate a finite wing's lift from its sectional airfoil shape?

I am struggling to get my head around a concept that I believe should be fairly simple to understand. Lift versus drag and AoA data of many airfoils are freely available, for instance the NACA 4-...
6
votes
4answers
2k views

Why don't airliners have rudders on the winglets?

There are a couple airplanes out there that use the winglet as the rudder, but why doesn't the winglet have a rudder on it to increase the turn of the aircraft?
9
votes
3answers
3k views

Why do airfoil's trailing edges point downward?

The trailing edge of and airfoil is mostly pointing downward. Is there any reason for that? Down wash increases drag and down wash is due to the direction of air pointing down. If the trailing edge is ...
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 ...
9
votes
2answers
2k views

Why do winglets reduce maneuverability (of fighter jets)?

In this answer Ethan makes the following statement concerning winglets on fighter jets: [Winglets] reduce maneuverability which is why you don't see a winglet on a fighter jet I could image that ...
10
votes
2answers
713 views

What are the effects of adding winglets to an aircraft not designed with winglets originally?

Are there any positive advantages or catastrophic effects on adding winglets to an aircraft not designed with winglets originally?
5
votes
3answers
2k 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.
7
votes
3answers
3k views

Why are modern aircraft wings often pointed instead being more rectangular?

When viewed from the Z axis (above or below), why are modern aircraft wings often pointed as they get towards the wingtips instead of maintaining the same surface area for their entire length? This ...
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
10
votes
1answer
2k views

Why are there different types of winglets? [duplicate]

If all winglets serve the same purpose (to reduce vortex drag), why do different aircraft have different winglets? This question is not trying to get a comparison of the development of winglets/...
8
votes
1answer
905 views

Is induced drag not caused by tip vortices?

According to most online resources, including NASA, induced drag is caused by wingtip vortices which induce downwash. However, in StackExchange I have found a few answers (Peter's and Jan's) that ...

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