I must confess, I dont get it? Maybe because it’s 1am, and I should be sleeping, but lift is caused by airflow over the wings…. Its nothing to do with the engine. The engine simply provides forward movement through the air to allow the air to pass over the wing.
Correct, and that produces lift.
If you assume that there is no wind, then what causes the airflow over the wing? Wind has nothing to do with it. Only the forward motion of the wing through the air is necessary.The ‘treadmill’ cancels out any forward movement, the aircrafts position relative to the runway remains the same and thus there is no increase in airflow.Only if the wheel brakes are on.
If you liken it to a person running on a treadmill. If you run on the open road you’ll feel air passing over your face…. You can run at any speed on a treadmill, but you will never feel any movement of air passing you. Forget treadmills, that’s a totally different set of circumstances.
How does the aircraft take off? Unless someone else know another way to take off without air passing over the surface of the wing, then I dont see how it’s possible.
Look at it this way. Forget the wheels and put the aircraft on skis, on the most slippery ice ever formed so that there is no friction between the skis and the ice. The slightest touch and the aircraft moves. OK, start the engine and the a/c moves forward (No wind situation) Does it matter if the ice moves in the opposite direction, can the ice drag the a/c backwards? Remember, no friction equals no connection of any sort. The engine is still pulling against the air and the a/c is still moving forward. It doesn’t matter how fast the two surfaces are passing each other (ski and ice) the a/c keeps accelerating until it takes off.
Now, imagine the ice is covered with a layer of small ball bearings then look very closely at the interface of ski and ice with the bb’s in between. As the a/c moves over them, they’ll rotate, very fast, without affecting the a/c nor the ice, right?
The faster the a/c goes, the faster the ice goes in the opposite direction, the faster the balls rotate when the a/c skis reaches and passes over them. That is exactly what the wheels do in the standard description, they rotate at twice the speed of the normal rotational speed for any given airspeed. They are just another very slippery interface between the a/c and the runway. They cannot slow anything down unless the brakes are applied and friction is added into the scenario. The a/c keeps moving forward at an every increasing speed, the runway matches that speed in the opposite direction and the wheels spin like ****. THE PLANE TAKES OFF.:diablo::diablo:
Sign In
