The shape of the upper and lower sides of an airplane wing is different. The top is convex and the bottom is flat. When the plane taxies, the wing is in air movement, which is equivalent to air flowing along the wing from the perspective of relative motion. Because of the different shapes of the upper and lower sides of the wing, the air on the upper side of the wing flows much more than the air on the lower side at the same time (the curve is longer than the straight line), that is, the air on the upper side of the wing flows faster than the air on the lower side. According to the principle of fluid mechanics, when the plane taxies, the air pressure on the upper side of the wing is less than that on the lower side, which makes the plane generate an upward buoyancy. When the plane taxies to a certain speed, the buoyancy reaches enough strength to make the plane fly. So, the plane went to heaven.
The principle of paper airplane flight is similar, except that it takes a short time and a short distance to glide, because there is no power.