Linked Questions

1 vote
2 answers
1k views

Are there any airplanes with the Centre of Gravity behind the Centre of Pressure? [duplicate]

We are used to seeing a forward CG in all airplanes, from a small Cessna to a large Boeing. I wonder whether any airplane with CG behind wing CP exists in production? Is it even possible? If so, what ...
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  • 532
52 votes
11 answers
20k views

Why do airplanes lift up their nose to climb?

Is it right that basically an airplane just needs to accelerate to climb? Greater velocity of an airplane leads to greater lift - and since its weight remains constant (or even decreases) - a greater ...
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  • 943
38 votes
3 answers
39k views

Are fighter jets designed to be so inherently unstable that a human can't fly one unassisted?

I'm told that in order to be more maneuverable fighter jets are designed in a way that makes them impossible for a human to control without the help of a flight computer. Is this actually true? ...
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  • 23.6k
31 votes
2 answers
157k views

What is the difference between centre of pressure, aerodynamic centre and neutral point?

I have just started learning some aerospace concepts, and I am not able to understand the difference between the three terms centre of pressure, aerodynamic centre and neutral point. What are their ...
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10 votes
4 answers
9k views

Do any aircraft out there use negative lift?

I think negative lift is where high pressure forms on the top of the wing instead of the bottom. I know that Indy cars use negative lift and some sports cars do, but do any aircraft exist that use ...
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  • 9,175
5 votes
1 answer
14k 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 ...
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  • 658
2 votes
5 answers
3k views

Do horizontal stabilisers provide any lift?

Do jumbo and smaller airliners' horizontal stabilizers provide any lift? Apart from maintaining the aircraft's angle of attack, can they perform the dual function that includes adding some lift as ...
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4 votes
3 answers
2k 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 ...
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  • 55
3 votes
3 answers
7k views

What causes tail-down force?

What phenomenon causes aerodynamic tail-down force? Why will there be more downforce on the tail when an aircraft picks up speed? What happens if the aircraft goes too slow - does this means less ...
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  • 2,359
1 vote
1 answer
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. ...
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  • 370
2 votes
4 answers
603 views

How much torque can a Boeing 747 apply when pitching?

I know this is a weird way of thinking about / quantifying this, but I'm trying to figure out how much torque a 747 can apply to itself when it pitches upwards (turning about an axis from wing to wing,...
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2 votes
1 answer
113 views

Tailplane/Equilibrium conditions [duplicate]

In regards to achieving equilibrium conditions, what is the relation between airspeed and the tailplane?
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