AND YOU ARE RIGHT! And everyone else that agrees with this is too(under the ideal conditions set by the original question)! The plane stays stationary because the forward velocity is cancelled by the conveyor (it is in a way pushing the plane back to where it came from at any given moment). It is true that planes gain velocity from the trust of the engines, but initially to take off its the friction of the wheels on the ground that allow it to move forward to create lift. If this was even possible, why in the hell would we have runways for?

 

the assumption that the plane stays stationary is false. see posts 30 and 12.

 

not only does the plane need thrust but it also needs lift. If the conveyer belt compensates the forward thrust of the aircraft than there is no lift created by the air rushing over the wing created high and low preasures above and below the wing. Therefore...no the bitch wouldnt take off

 

Your analogy with the hot wheels cars is not clear because the car is not trying to move in the opposite direction when the paper is being pulled in the other! Have you ever ran on a treadmill and felt wind flying by you? I don't think so.

 

Exactly!

 

No, it will not.


1. no air going under the wing for liftoff

2. no air going into the engine for combustion.



the dyno analogy is probably the clearest. the car is on the dyno...but it isnt moving. you need fans to generate/imitate the air that is cooling the radiators. a plane needs that force of air for liftoff and combustion.

 

How is that false? He stated in the original post that the conveyor speed is exactly the same speed as the plane, but in the opposite direction...causing a fixed position. This means that the plane has an airspeed of zero, and no lift will be created. Listen to Kestrel, the guy is going for his frigging PhD in engineering.

 

My point with the hot wheels analogy is that the ground moving under a vehicle isn't going to make the vehicle move at the same rate. The ground moving is only going to make the wheels spin forward.

 

Kestrel is arguing a complelety parallel argument. I'm not talking about the conveyor moving the air around airplane. I'm talking about the conveyor not moving the airplane. My argument is that the conveyor is going to make the wheels on the airplane spin, and not make the entire airplane move at the velocity of the conveyor.

FWIW, I'm going for my dual masters in Physics and Mechanical Engineering.

 

all the lift and drag aside, it is an impossibility for a conveyor belt to hold an airplane with engines at full tilt stationary. aircraft wheels consist of tires, breaks, and linkage to the airplane. the only resistance is that of the brakes and only if depressed. with that said, no matter how fast this magical conveyor turns, it will not be able to limit forward momentum because the wheels act similar to brtecson's matchbox analogy. the thrust from the engines will push the aircraft forward regardless of how fast the conveyor turns thus generating lift to get off the ground.

the wheels and conveyor in this scenario have absolutely no bearing on the airplanes ability to create and maintain forward momentum. they are completely seperate from each other. this scenario is misleading in that it offers factors that are unnecessary to the equation in a way that, at first glance, seem necessary.