Aircraft are man-made vehicles intended to operate while flying through Earth's atmosphere.

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680 views

Why do vapour cones form around jet fighters?

Apparently this phenomenon has nothing to do with jets breaking the sound barrier and has something to do with the Prandtl-Glauert singularity as described on Wikipedia. But, the Wikipedia article ...
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3answers
4k views

why aren't there nuclear powered aircraft?

I know this might sound like more of an engineering question that about physics, and it probably is, but bear with me: i'm still not sure if the answer to my question lies in the physics or in the ...
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21 views

Fluid Dynamics applied to Aircraft wings [duplicate]

On aircraft wings, the bottom is flat and the top is curved. I know this benefits the aircraft by producing lift, but I wish to understand how. I'm told it has something to do with how fluids behave.
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1answer
46 views

Coriolis Effect vs airplane

So, if I build a highway from north pole towards equator and sit in a car, speed pretty fast towards it, I should feel force with the Earths rotation due to the different rotation speeds of this ...
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2answers
397 views

Why ballasted gliders fly faster

The fact: Gliders have ballast tanks that can be filled with water. The addition of ballast increases weight, and this allows the glider to fly at faster airspeeds while maintaining the same glide ...
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1answer
67 views

Why don't we build helicopter based space shuttles?

As seen in this video: the principle of the helicopter does work in space. So we could make a helicopter based space shuttle! It would be easier to navigate with it than with propulsors.
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6answers
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Turning an Airplane. What actually causes the circular motion in a banked (roll) turn?

Basically I'm wondering if this is correct. Which essentially says that you need a torque to get the nose of the craft to turn and that this is provided by the rear tail surfaces. After trying to ...
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1answer
248 views

Why are the backs of airplanes curved?

I get the front part, but why is the back curved too? I do not see a problem with the back being flat.
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3answers
275 views

Is fuelless aviation possible?

I've read the article Gravity powered aircraft flies with no fuel. This is making me confusion, as I can not discern if it is credible. Is it an hoax?
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3answers
148 views

Disconnected aileron/surface deflection in terms of speed?

Would a disconnected surface, especially aileron, deflect upwards as you slow down due to increased alpha? I figure out it is more likely to deflect upwards as you increase your airspeed, thus having ...
149
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9answers
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What really allows airplanes to fly?

What aerodynamic effects actually contribute to producing the lift on an airplane? I know there's a common belief that lift comes from the Bernoulli effect, where air moving over the wings is at ...
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5answers
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Is speed of propeller-driven airplane limited by the speed of sound?

Mine line of thoughts goes like this: A propeller is effectively pushing itself away from molecules of air. The best any propeller can do is to create total vacuum in the front of itself. The ...
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0answers
30 views

The velocity of air on an airfoil

They say that velocity of the top layer on an airfoil is higher than the lower layer. But, according to the continuity principle of fluid, the velocity of air is inversely proportional to the surface ...
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1answer
100 views

Since Earth spins, would an aircraft travelling opposite to direction of Earth spin take less time? [duplicate]

Suppose we want to reach the point on earth which in relative terms is exactly on the opposite end of the sphere we call earth (I know it is not an exact sphere). We either dig vertically downwards, ...
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2answers
873 views

Movie airplanes and suction

Having watched a recent action movie (with zombies in it) I wondered whether the suction from a hole in the airplane's hull would really be able to rip out luggage, persons and even seating benches. ...
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3answers
1k views

Aircraft Level Flight Trajectory

An aircraft climbs to 15000 feet and enters 'level flight' phase. My basic knowledge of physics says that forces on the aircraft at this time are balanced - as seen in this diagram. Would an ...
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10answers
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Why do space crafts take off with rockets instead of just ascending like an aircraft until they reach space?

I guess it's not a very educated question, but I never quite understood why spacecrafts have to shoot up and can't just reach space by simply continuing an upwards ascent like an airplane.
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3answers
90 views

How much power can support an object to float in the air near the surface of the earth?

If we want to float an object of 1KG in the air near the surface of our earth (the object can move slowly but shouldn't move very fast like a flying plane), at least how much power do we consume? I ...
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3answers
166 views

Coriolis force on bullet vs airplane

Why do airplanes experience negligible Coriolis force while bullets experience the Coriolis force in long range shooting, even though the mass of airplane is much bigger than a bullet?
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1answer
56 views

What is the top speed of the SR-72 aircraft? What affects would traveling at this speed have on the human body? [closed]

What is the top speed of the SR-72 aircraft? What affects would traveling at this speed have on the human body?
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0answers
41 views

Calculating/estimating heat transfer losses for hot air balloon (lantern)

I'm trying to build a flying lantern / hot air balloon that flies as close to hovering as possible (as opposed to up-up and awaaay). To see if this is feasible I'm trying to simulate as much as I can ...
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3answers
967 views

Why does an airplane need to climb during a takeoff even if it is in emergency situation?

Right after take-off (which means an airplane already exceeded V1) it is recommended that an airplane keeps climbing even when emergency occurs. Beside worries of crashing into houses and buildings by ...
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2answers
104 views

Why is an airplane able to increase thrust without moving?

I was just watching some documentaries and saw planes building up power in the turbines without moving. I thought about it and remembered, that this happens before every take off. So, why is this ...
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2answers
400 views

If an airplane is flying sideways, is it in free fall?

If a plane turns 90 degrees such that it is flying sideways, is it accelerating towards the earth at the usual 9.8 m/s^2? My guess is that the plane must be in free fall because I don't see what ...
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1answer
35 views

How to approximate lag of roll of a bird (or RC airplane)?

When an airplane rolls using ailerons, the ailerons itself are changing their state quite instantly. However, in order for the airplane to actually start to roll, it should take a considerable amount ...
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1answer
284 views

Alternative air transportation and magneto-aerodynamics

Firstly, I am not a big fan of UFOs, however, a flying saucer makes me think if is there another, comparatively agile way to travel through the air without jets, turbines or propellers (balloons are ...
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76 views

When an aircraft flies over, glass window vibrates…Infrasound?

When an aircraft flies over, my big glass window vibrates, making a ticktack beating. Its frequency sounds low, less than 10 beats per second actually. I'm wondering about the mechanism of this ...
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1answer
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Paper plane between two fans - is this possible?

The setup: two fans facing each other, distance around 1m. Both are turned on. In between them, place a simple paper plane and according to this video, it will fly. ...
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3answers
236 views

Why aren't stratospheric balloons compressing their helium to descent? [closed]

I can't find a reference of a working stratospheric balloon mounted with a compressor to control its altitude. Is there a big physical difficulty (such as compressor weight/power ratio, or power ...
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2answers
666 views

Beryllium Vacuum Sphere Boat/Aircraft

Is it possible to make a solid rigid evacuated "balloon" out of Beryllium or other elements or alloys? The critical buckling pressure at which an evacuated sphere is given as $$ ...
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1answer
188 views

Speed of sound and Break the sound barrier

What happens when plane exceeds the speed of sound? and What is the interpretation of the conical shape that appears behind the plane?
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0answers
32 views

If i had a aero-nautical object [closed]

If i had a aero-nautical object with a span of 10 feet and a weight of 40 pounds with a strong gale blowing do you think i could make it off a cliff with out plummeting to total utter death?
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0answers
446 views

Pressure required on a wing to lift a plane and the speed required to create this pressure difference [closed]

An aircraft has a single wing with a total area of A =1 2.6 m2 (assume that the thickness of the wing is negligible). When in motion, the air flows under the wing at the velocity that the aircraft ...
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7answers
10k views

What will happen if a plane trys to take off whilst on a treadmill?

So this has puzzled me for many a year... I still am no closer to coming to a conclusion, after many arguments that is. I don't think it can, others 100% think it will. If you have a plane trying to ...
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7answers
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Does it take significantly more fuel to fly a heavier airplane?

I was reading in the papers how some-airline-or-the-other increased their prices for extra luggage, citing increased fuel costs. Now I'm a bit skeptical. Using the (wrong) Bernoulli-effect ...
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2answers
160 views

Airplane on a treadmill [duplicate]

I've heard conflicting answers, and would like to see the record set straight: An jet/propeller airplane is traveling on a giant treadmill at takeoff speed. Will the plane takeoff, or will it remain ...
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3answers
906 views

How much effect does the Bernoulli effect have on lift?

I understand that the Bernoulli effect is a flawed explanation for the cause of lift, and does not cause much at all, but how much? Is there any experimental data on the force caused by the ...
28
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13answers
2k views

What does a wing do that an engine can't?

This isn't a question of how a wing works -- vortex flow, Bernoulli's principle, all of that jazz. Instead, it's a question of why we need a wing at all. A wing produces lift, but why is that ...
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2answers
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How can airplanes fly upside down?

I've read many times, including here on this very site that the commonly known explanation of flight is wrong, and that airplanes can fly because the shape of their wings deflects air down. This makes ...
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0answers
72 views

Why air above airplane's wing moves faster? [duplicate]

One explanation I read: Because of the wing's geometry, the "upper" side of the wing is longer, so the air has to travel faster: My wondering: Who said (and what was his/her explanation) that ...
4
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1answer
106 views

How to relate wingtips vortices with the energy loss it engenders?

On planes, wingtips vortices engender a loss in terms of lift, and an incresed of the drag, so an energy loss. Is there any possibilty to find a mathematical model relating both ? Thanks for the help. ...
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1answer
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Effect of Earth's magnetic field on aeroplanes?

As an aeroplane accelerates through the Earth's B-field, it experiences a changing flux $d\phi \over dt$ and a potential difference is induced along its wings. Given the wings are made of metal and ...
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2answers
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Why does an airliner burn more fuel at lower altitudes?

At lower altitude an aeroplane usually has more lift. However an aeroplane flying at low altitudes (with gear/flaps up) at low velocity burns the same amount of fuel it would flying much faster at a ...
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3answers
379 views

How does a pressure suit work?

I recently learnt that a suit called pressure suit is worn by fighter plane pilots to prevent red-outs and black-outs. And it seems to be work by - "..applying pressure to selective portions of ...
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2answers
215 views

When is the stress on an airplane the highest?

Something I´ve been wondering for a long time: At what point during a flight is the stress on an airplane the highest? Is it during take-off, landing or during (light/moderate/severe) turbulence? ...
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2answers
876 views

Are the hypotheses of the Bernoulli equation satisfied for a bird or airplane wing at low Mach number?

A previous question by David Zaslavsky was a request for a broad, "how things work" type of explanation of the lift of an airfoil. The answers given there are enlightening, but don't address a more ...
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5answers
4k views

Why planes have propellers in front but watercraft have them behind?

Why do propeller airplanes mostly have their propellers in front (of the fuselage or wings) while ships and boats mostly have them at the back? I realize that there are aircraft with pusher ...
3
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1answer
135 views

Pressure difference between 2 side of wings of aircraft

I understand why the pressure is reduced above the wings of aircraft, but when I read books and look for information, it says that the air is compressed below the wings, I do not understand why it is? ...
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1answer
150 views

Relative motion of airplane in the wind [closed]

I have a relative motion problem in which I cannot get my answer to match the book answer. The question is: An airplane has to travel $189\, \mathrm{km}$ due east to point $B$ from point $A$. It ...