What actually happens at take-off?
Thread Starter
What actually happens at take-off?
Very basic question with probably a basic answer.
How does an aircraft rotate during the take-off? I know the pilot pulls on the yoke but what does that do to the aircraft's devices and how does that create the rotation?
Presumably once the nose is in the air the plane gets to a speed at which the wings have enough lift to simply leave the ground?
How does an aircraft rotate during the take-off? I know the pilot pulls on the yoke but what does that do to the aircraft's devices and how does that create the rotation?
Presumably once the nose is in the air the plane gets to a speed at which the wings have enough lift to simply leave the ground?
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Pulling back the yoke pushes the tail down.
That increases the tilt (angle-ofattack) the wings present to the airflow. That increases the lift and away you go.
You can get airborne without pulling back on the yoke. Just let the plane keep accelerating. Eventually the speed will generate enough lift and again your flying. That does use a lot of runway though!
Speed and angle-of-attack combine to give lift. Although too much angle-of-attack and it all goes wrong and you fall out of the sky (stall).
That increases the tilt (angle-ofattack) the wings present to the airflow. That increases the lift and away you go.
You can get airborne without pulling back on the yoke. Just let the plane keep accelerating. Eventually the speed will generate enough lift and again your flying. That does use a lot of runway though!
Speed and angle-of-attack combine to give lift. Although too much angle-of-attack and it all goes wrong and you fall out of the sky (stall).
Hi espada - not seen you in another place of late!!
AB - aka Bromptonaut!!
AB - aka Bromptonaut!!
Thread Starter
Indeed AB - got fed up with Dog and his politics.
Thank you all above (well some of you) for the useful information. Elevators up; tail down; nose in air; increased lift and away you go.
Thank you all above (well some of you) for the useful information. Elevators up; tail down; nose in air; increased lift and away you go.
Must be lift fairies else how would taildraggers fly? 
And we don't wish to get Espada confused with the idea that, in some aeroplanes, you have to push the stick forward during the takeoff roll.
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It's not speed it's how loud is the engine.
You see on a taildragger with a very loud engine there is no need to push the stick forward.
The loud engine will attract sufficient lift fairies for it to fly eventually with no stick input.
(perhaps)
You see on a taildragger with a very loud engine there is no need to push the stick forward.
The loud engine will attract sufficient lift fairies for it to fly eventually with no stick input.
(perhaps)
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Dear Chiglet how could you be so horrible about the lovely Trident "Ground Gripper" yes but once the super stickey tyres left the runway and the wheels were up the words "pocket Rocket" spring to mind .you'll be saying next that the reason for the off set nose leg was to stop it making a thumping noise as it wouldn't keep hitting the runway center line lights.
Can we old Aviation types give the poor originator the right answers to his question, I thought on the old tail draggers the yoke was eased forwards to get the tail up to gain flying speed but what do I know I was AVIONICS
Can we old Aviation types give the poor originator the right answers to his question, I thought on the old tail draggers the yoke was eased forwards to get the tail up to gain flying speed but what do I know I was AVIONICS
Last edited by avionic type; 14th Jun 2011 at 18:18. Reason: A plea added
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OK the truth about flying a taildragger -
Lift equation states that the lift is proportional to the aoa and square of the velocity.
Planes (sorry 'Planes) take off when the lift produced is greater than the weight.
On a low powered taildragger, without putting the stick forward one may not accelerate sufficiently on a short runway to satisfy the velocity required for flight as in the nose up attitude it is very draggy. The tail is brought up to reduce drag and aid acceleration. Strangely this actually reduces the aoa so is in effect the opposite of a rotation, it's fine though because eventually the velocity part of the equation catches up and the thing flies off or is encouraged to un-stick with a relaxation of the forward pressure to put the aircraft into the climb attitude.
On more powerful types (Super Cub) you can achieve a three point take-off with the tail down. There is sufficient power to accelerate and lift off - all be it with a high angle of attack (near critical angle). This is OK as long as the pilot puts the nose down and continues the acceleration in ground effect before continuing to the climb. POH technique for soft field take-off of the Super Cub. Most bring the tail up though, because it is fun and looks cool. NOTE: There are aircraft where when on the ground the wing is at or above the critical aoa - they will never take-off in the three point position)
Between the fully tail-up and tail-down take off, you have the partial tail up. This is often preferred for types with very large props and lots of swirling mass up front. The upside of this technique is one lifts off in the climb attitude and only has to maintain it. The downside it it is very easy to become airborne due to a gust and drop back down on the runway during the take-off run. (scary)
Most of the problems with taildraggers are caused by the strange forces involved confusing the lift fairies, this can lead to nasty swings to the left or right depending on engine rotation and the side where most lift fairies fall off the wing and tailplane... Oh OK the first bit was true (probably).
Lift equation states that the lift is proportional to the aoa and square of the velocity.
Planes (sorry 'Planes) take off when the lift produced is greater than the weight.
On a low powered taildragger, without putting the stick forward one may not accelerate sufficiently on a short runway to satisfy the velocity required for flight as in the nose up attitude it is very draggy. The tail is brought up to reduce drag and aid acceleration. Strangely this actually reduces the aoa so is in effect the opposite of a rotation, it's fine though because eventually the velocity part of the equation catches up and the thing flies off or is encouraged to un-stick with a relaxation of the forward pressure to put the aircraft into the climb attitude.
On more powerful types (Super Cub) you can achieve a three point take-off with the tail down. There is sufficient power to accelerate and lift off - all be it with a high angle of attack (near critical angle). This is OK as long as the pilot puts the nose down and continues the acceleration in ground effect before continuing to the climb. POH technique for soft field take-off of the Super Cub. Most bring the tail up though, because it is fun and looks cool. NOTE: There are aircraft where when on the ground the wing is at or above the critical aoa - they will never take-off in the three point position)
Between the fully tail-up and tail-down take off, you have the partial tail up. This is often preferred for types with very large props and lots of swirling mass up front. The upside of this technique is one lifts off in the climb attitude and only has to maintain it. The downside it it is very easy to become airborne due to a gust and drop back down on the runway during the take-off run. (scary)
Most of the problems with taildraggers are caused by the strange forces involved confusing the lift fairies, this can lead to nasty swings to the left or right depending on engine rotation and the side where most lift fairies fall off the wing and tailplane... Oh OK the first bit was true (probably).
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Of course the Shackleton got round the "Swing on takeoff" by having conta- rotating props, plus the MK1s and 2s were taildraggers and the lift fairies were happy bunnies .
I shall now retire to my atomic bomb proof shelter to await the flak.
I shall now retire to my atomic bomb proof shelter to await the flak.
