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

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138
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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 ...
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 ...
22
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2answers
12k views

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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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 ...
17
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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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2answers
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Why can't supersonic planes “just fly higher” to go faster while maintaining cost?

First post to this site, and I've got at most a high school background in physics - I really appreciate any answer, but I may not be able to follow you if you're too advanced. I suppose this goes for ...
13
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5answers
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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 ...
13
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4answers
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Does the rotation of the earth dramatically affect airplane flight time?

Say I'm flying from Sydney, to Los Angeles (S2LA), back to Sydney (LA2S). During S2LA, travelling with the rotation of the earth, would the flight time be longer than LA2S on account of Los Angeles ...
13
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3answers
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What causes an aircraft to roll when rudder is applied

When continuous rudder is applied in a typical light aircraft during straight and level flight at "normal" flying speeds and altitudes, the primary effect is that the aircraft will yaw to the left - ...
12
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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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3answers
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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 ...
10
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2answers
782 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
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Does my model aircraft propeller beat the sound barrier?

I fly model aircraft. Recently I changed from a "1300kv" motor to a "1500kv" motor. The difference is in speed; the 1300kv can go about 16,400rpm full-throttle and with a fully charged battery and the ...
8
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3answers
318 views

Airplane with banner in a windy day

Will the banner of this airplane be always in the proper direction if the airplane flies in any direction on a windy day?
8
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3answers
798 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 ...
8
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2answers
3k views

What is the optimal design for a paper airplane? (Or, at least, how can you approach it?)

Having only really known two designs for paper airplanes since my days as a child, one which flies about eight feet and another which flies about ten feet, I have always wondered how people manage to ...
7
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4answers
698 views

Why does an airplane have more lift near the ground?

I've noticed that an airplane appears to have more lift when it's almost touching the ground then it has 100 feet or more in the air. What causes this to occur?
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5answers
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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 ...
5
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7answers
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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 ...
5
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1answer
364 views

why can't you use your cellphone on an airplane? [closed]

why airplanes are banned with use of cellphones? What were the impacts while we answer an call or make an call ,what was the physical reason behind the ban of using cellphone inside airplanes ? I ...
5
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1answer
2k views

time difference with airplane travel direction

a fight from east to west, (e.g. Australia melbourne to perth) takes longer than travel backwards. (west to east). What's the reason?
5
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4answers
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Why do aircraft inner wings lose lift when turning?

first question here, so please be gentle! I'm reading an entry-level engineering course book and am currently up to discussion of aircraft design. There's one particular statement that is unclear to ...
5
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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. ...
4
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1answer
382 views

Can a hovering helicopter travel half the globe in 12 hours? [duplicate]

Suppose we have a helicopter that is able to stay stationary in flight for extended periods of time. If such a helicopter stayed at point A in the sky for 12 hours straight, would it reach the other ...
4
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3answers
370 views

atmospheric phenomenon? What causes condensation trails to converge?

This air plane just caught my eye. Two contrails apparently are flowing backward, slightly off-centered and then ultimately converge, giving the overall shape of a very narrow rhomboid parallelogram, ...
4
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3answers
893 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 ...
4
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3answers
2k views

How much lift does an airplane get from its wings, vs the rest of the airframe?

Consider a big commercial airliner, like a 727, 747, or a 787. At cruising altitude, under standard conditions, how much of the lift of the aircraft comes from the wings, and how much from the rest ...
4
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1answer
528 views

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 ...
4
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1answer
93 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. ...
3
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2answers
96 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 ...
3
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1answer
368 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 ...
3
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3answers
275 views

How to compute the speed necessary for an airplane to fly?

I give some physics lessons to a friend. She asked me a question that I am unable to answer. Could you help me ? A plane has a weight of $2\times10^6$kg. The surface of the wing is $1200 \text{m}^2$. ...
3
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2answers
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What happens when a supersonic airplane flies through a cloud?

What happens when a supersonic airplane flies through a cloud? Will it punch a hole or is it more like a bullet through water (= hole closes immediately after the aircraft has passed)? Is there some ...
3
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3answers
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Could a real-life X-Wing fly in Earth's atmosphere?

From an aerodynamic point of view, could a full-size aircraft of X-Wing design fly in Earth's atmosphere? Assuming you were free to add control surfaces here and there, could the wings in open ...
3
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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 ...
3
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1answer
110 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? ...
2
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2answers
154 views

How fast can toy helicopters change the turning direction of their propellers?

I saw someone do some tricks with a toy helicopter where he would turn it upside down for a while and it would still stay in the air. I thought it should have crash or at least not fly for very long ...
2
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2answers
2k views

Paper airplane physics

I am working on a game involving flying and steering a paper airplane for WP7. I want the plane to fly just like how normal paper airplanes fly (see this game for an example ...
2
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2answers
1k views

Whats the anti-torque mechanism in horizontal take-off aircraft?

In most helicopters there is the anti-torque tail rotor to prevent the body from spinning in the opposite direction to the main rotor. What's the equivalent mechanism in horizontal takeoff single ...
2
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1answer
710 views

How does a V formation save fuel for the lead plane?

I'm watching an episode of Mythbusters where they show aircraft saving 3-5% fuel when flying in a tight V formation. Interestingly, this also applies for the lead airplane. How is that possible for ...
2
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3answers
244 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?
2
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1answer
114 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?
2
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1answer
113 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 ...
2
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4answers
781 views

How does an aeroplane maintain balance during maneuvers?

I understand the principle behind flight, how the lift is generated etc. What I don't understand is when there are maneuvers made where the plane flies such that the wings are in vertical plane, how ...
2
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3answers
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Flying a toy helicopter inside an accelerating train [duplicate]

Scenario: You ride in a train, you have this helicopter toy. The train is not yet running when you flew your helicopter on a constant altitude (say 1 meter above the train's floor). Question: What ...
2
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2answers
539 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 $$ ...
2
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1answer
195 views

Application of plasma actuators for flow control of moving objects

I've recently been to a converence on plasma physics were, to my surprise, a lot of presentations were concerned with plasma actuator. Could someone, preferably in the field, tell me how long people ...
2
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3answers
146 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 ...
2
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2answers
488 views

Forces on an airfoil

I'm building an airplane (Super Baby Great Lakes) and I'm wondering something about airfoils. In particular (this plane is fabric covered), I'm wondering about the lifting forces on the main wings. ...
2
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0answers
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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 ...