What is angle of an airplane with Horizon in takeoff time?

Answer 1

The angle of the airplane, (or more importantly the wing) at the time of take-off depends on a few factors. While flat on the ground, there is a built in angle to the wing (called the chord) in relation to the level centerline of the aircraft ( called the datum). This is called the angle of incidence. As the pilot accelerates the aircraft down the runway, aerodynamic force on the elevators will cause the nose to rise up. The difference between the angle the wind is hitting the aircraft and the chord line is called the Angle of Attack. At a steady speed, the bigger the angle of attack, the more lift a wing will produce up to a certain point (usually about 25 degrees). At that angle, the wing stalls and lift is lost on the wing until the AOA is reduced, granted the speed is constant. Also if the wing is held at a perticular AOA, and wind speed over the wing is increased, lift will increase also. So it really depends on the speed of the aircraft and how much lift it need to get off the ground. But the rotation angle is different on every plane. Usually they try to keep the angle the same and adjust the speed of the take-off to make more lift.