Plane take off
#1
Original Poster



Join Date: Feb 2008
Programs: UA AA MR HH B6
Posts: 1,430
Plane take off
When a plane takes off, what is it that gives them that extra lift? Is there something on the wings that they do to point the plane up? What are the pilots moving when they move that handle looking thing forward?
Thanks in advance
Thanks in advance
#2

Join Date: Dec 2006
Location: SJO
Programs: CO Gold
Posts: 1,230
Interesting question...that can generate tons and tons of pages of info
the lift that makes the plane fly comes from the difference of pressures between the two sides of the wing (up / down) , for more info on this look
http://library.thinkquest.org/3142/lift.htm
the handle that points forward (I imagine you are talking about is the throttle, look at picture in the following link)
http://www.ueet.nasa.gov/StudentSite...sofflight.html
the lift that makes the plane fly comes from the difference of pressures between the two sides of the wing (up / down) , for more info on this look
http://library.thinkquest.org/3142/lift.htm
the handle that points forward (I imagine you are talking about is the throttle, look at picture in the following link)
http://www.ueet.nasa.gov/StudentSite...sofflight.html
#3
Suspended
Join Date: Jun 2009
Posts: 3,096
On takeoff, the aircraft will be "trimmed" in advance. The elevator will be set to the most ideal position for the aircraft's weight and balance, so it will lift itself at a certain speed.
Also, most take offs are done with a certain amount of flap down. This lowers the stall speed of the aircraft and therefore reduces the necessary speed to generate sufficient lift. This varies with altitude and runway length.
#4
Join Date: Dec 2006
Posts: 1,452
Most civilian planes rotate on takeoff.
There are a few planes which do not rotate on takeoff. Notably Boeing B-52 bomber, which has its wings tilted relative to the fuselage so that they will produce lift as the plane runs on the takeoff run, and when the plane reaches takeoff speed, the lift exceeds weight and it rises up.
This is generally a bad arrangement for a number of reasons (one of which is probably poor effectiveness of brakes at high speed on landing or aborted takeoff).
Taildraggers like DC-3 usually use their elevator to lift tail up early in the takeoff run. This prevents the wing from giving lift and decreases drag during the takeoff run. When rotation speed is reached, elevator is used to lower the tail, so the wing starts to give lift and lifts the plane off ground.
On planes with nosewheel, the wind is placed so that it gives little thrust when the plane is standing level. When rotation speed is reached, the elevator presses the tail down, so that the wing starts to give lift and causes liftoff.
Now, throttles are the cockpit controls which increase or decrease engine thrust. They are advanced at the start of takeoff run, not on rotation.
Elevator is controlled with yoke, or with joystick.
There are a few planes which do not rotate on takeoff. Notably Boeing B-52 bomber, which has its wings tilted relative to the fuselage so that they will produce lift as the plane runs on the takeoff run, and when the plane reaches takeoff speed, the lift exceeds weight and it rises up.
This is generally a bad arrangement for a number of reasons (one of which is probably poor effectiveness of brakes at high speed on landing or aborted takeoff).
Taildraggers like DC-3 usually use their elevator to lift tail up early in the takeoff run. This prevents the wing from giving lift and decreases drag during the takeoff run. When rotation speed is reached, elevator is used to lower the tail, so the wing starts to give lift and lifts the plane off ground.
On planes with nosewheel, the wind is placed so that it gives little thrust when the plane is standing level. When rotation speed is reached, the elevator presses the tail down, so that the wing starts to give lift and causes liftoff.
Now, throttles are the cockpit controls which increase or decrease engine thrust. They are advanced at the start of takeoff run, not on rotation.
Elevator is controlled with yoke, or with joystick.

