Linked Questions

25
votes
5answers
82k views

What does the term “trimming” most commonly mean in aviation?

Why does an airplane need trim, and what does it do during the flight? Does an autopilot adjust the trim automatically?
21
votes
3answers
6k views

What does it mean for a plane to be aerodynamically stable?

I've heard that most planes (excepting fighter jets) are "aerodynamically stable." What does that mean? Let's say you're cursing around in a Cessna 172 without autopilot, and you take your hands off ...
15
votes
2answers
14k views

What is the reason for the poor low-speed characteristics of sweptback wings?

I know there are advantages of swept-back wings delaying shock-wave allowing a aircraft to fly faster. However, what are the disadvantages. I know one of them is that they have very poor low speed ...
13
votes
3answers
43k views

How does wing sweep increase aircraft stability?

I was told at one point that the sweep of a wing can help with the straight line stability of the craft, in fact I think it's one of the main systems that keeps flying wings flying straight (like the ...
9
votes
4answers
3k views

Do all aircraft need to have horizontal and vertical stabilizers?

Are (or were) there any operational aircraft that don't have horizontal and vertical stabilizers or canards? If so, what's the effect on how they fly?
10
votes
2answers
5k views

How is pitch controlled in a flying wing?

How do delta wing or flying wing aircraft maintain their pitch attitude in the absence of an elevator? I understand that the ailerons on the wings do control the banking/roll, but they are ...
8
votes
3answers
2k views

Why is the tail group of virtually every airplane swept instead of straight?

Even low performance airplanes like ultralights have their tail group (vertical and horizontal stabilizer with rudder and elevator) swept backwards knowing fully well that a straight tail group will ...
7
votes
1answer
7k views

What is the best design for a small flying wing with special flight envelope?

I'm designing a small, light and portable flying wing UAV that will launch and land vertically via a Tilt-rotor system. I'm attempting to use the program XflrV5 but am having difficulty understanding ...
5
votes
1answer
1k views

What is the need for twist along a wing?

Why should a wing even have a twist towards its outermost chord? How did that even come about? Why can't it be straight and aligned as it usually is?
0
votes
4answers
209 views

Why should I not use a “lifting tail” on my ultralight design?

In my misspent youth I designed and built many rubber, gas, and RC models. When I wanted good climb and glide I used a aft CG [60 to 80%] and a lifting tail. I had no stability or control problems, ...
2
votes
2answers
299 views

What are the disadvantages of a tailless ultralight design?

What are the disadvantages of a tailless ultralight design with say 20 deg swept back wings with wing tip rudders, 20-60mph, max 25 hp? I'm not an aerospace engineer, so I stand to be corrected: The ...
2
votes
1answer
445 views

Why does the effective alpha/CL increase at wingtip of swept wing?

If anybody could explain this in an intuitive way I'd really appreciate it. I haven't been able to find a clear answer on this. I understand that the increase in effective AoA/CL and the spanwise flow ...
0
votes
1answer
49 views

A question regarding airfoil parameters

If a hypothetical aircraft, which is a tailless straight flying-wing with no fuselage, has the following characteristics: moderate forward sweep an aspect ratio = 9 a dihedral angle of 3 degrees a ...