Linked Questions

6
votes
3answers
11k views

Should the pitching moment be up or down?

I had a question regarding the direction of the pitching moment. To make sure we are on the same page, here is what I know so far (please correct me if I am wrong). Lift acts through center of ...
6
votes
3answers
7k views

What is the function of the tail section on a fixed-wing aircraft? [duplicate]

In a generic fixed-wing aircraft like a Cessna, what is the function of the tail section, i.e. the rudder and elevators?
5
votes
3answers
958 views

Why aren’t there any lifting-canard airliners?

A lifting-canard aircraft, such as the Long-EZ, is an aircraft with the main wing at the back end of the fuselage and a pair of small, highly-loaded canards attached to the forward fuselage; the ...
5
votes
3answers
2k views

How is the centre of lift and centre of gravity misalignment problem solved in Delta wing aircraft?

Since Delta winged aircraft don't have horizontal stabilizers to produce down force, how is that problem solved ?
2
votes
3answers
893 views

What are the disadvantages of a Tail providing lift? (tandem-wings included)

Most aircraft feature the tailplane configuration, which requires the main wing to provide higher lift than the weight of the plane itself, what seems counterproductive. Few aircraft have featured ...
1
vote
3answers
979 views

What is the relationship between centre of gravity, centre of pressure and pitch?

Ok so I've got a couple of questions regarding CG, CP and pitch 1) When the aircraft is taking off, is the tail down force required to pitch up the aircraft high? Because the aircraft always has a ...
7
votes
2answers
1k views

Why does aircraft stability increase when it transitions from subsonic to supersonic flight?

I am puzzled why would the aircraft be more stable at high speed flight at high altitudes. Given that the Centre or Pressure moves gradually towards the 50% MAC region, once past Mcrit. Has this got ...
6
votes
2answers
1k views

How to trim in level flight when speed increases?

What is required to happen to control surfaces and trim tabs to remain trimmed in straight and level flight, as speed increases? (for a GA propelled aircraft) My manual tells me that the elevator ...
4
votes
2answers
165 views

Calculate pitch balance of RC glider?

Today, I played with styrofoam gliders with my kids; I made an asymmetric wing, asymmetric horizontal tail, symmetric vertical tail, and attached these to one stick for the fuselage. I've had big ...
9
votes
1answer
1k views

Are there any fly-by-wire airliners with negative or near-neutral pitch stability?

Are any modern commercial airliners with fly-by-wire flight control systems designed with negative or near-neutral pitch stability so that they can take advantage of the capability of such systems to ...
5
votes
1answer
12k views

Where is the best center of gravity?

I'm designing a plane, and I have a question. What is the best place for the center of gravity, relative to the center of lift? I've heard that it's best put just behind the center of lift, but I ...
2
votes
1answer
955 views

Why does pitching moment coefficient decrease with an increase in the angle of attack?

Slope of Cm vs alpha graph is negative, why it is so? The attached graph is from https://en.m.wikipedia.org/wiki/Pitching_moment , this graph is for cambered airfoil, as pitching moment is zero for ...
2
votes
1answer
81 views

Tailplane/Equilibrium conditions [duplicate]

In regards to achieving equilibrium conditions, what is the relation between airspeed and the tailplane?
1
vote
1answer
1k views

How to calculate the location of C.G. A.C. & N.P. in static longitudinal stability?

We are in the conceptual stage of design and, using Raymer & Nicolai as references, I am doing a rough calculation of "power off" neutral point (N.P.) to find the optimum c.g. and a.c. positions. ...
0
votes
0answers
298 views

How does a horizontal tailplane stabilize a cambered airfoil aircraft? [duplicate]

The picture below shows the location and movement of centre of pressure when angle of attack is increased. Consider the aircraft is trimmed at the second airfoil in the picture. Thus the horizontal ...

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