During a turn the nose goes down. Why ?
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During a turn the nose goes down. Why ?
Hi,
If I start a coordinated turn with my airplane, the nose is automatically going down and I need to pull in the stick to maintain the nose on the horizon, thus level flight.
Why is that ?
This is NOT because of the increase in apparent weight (which is the vector sum of mv²/r + weight) because apparent weight applies at the Center of Gravity so its increased value does not affect the moment around the CG.
My hypothesis is that during the initial part of the turn I bank the aircraft. Then during the first seconds, a non symmetrical relative wind appears on the fin, generating a total reaction on the fin which is directed upwards and in the opposite direction of the turn. That aerodynamic reaction on the fin would create a moment nose down around the CG (and also a moment which will put the nose of the aircraft in the relative wind as a weather vane and re-establish a symmetrical airflow on each side of the longitudinal axis of the aircraft).
What do you think about that ?
Any other idea/opinion is more then welcome.
If I start a coordinated turn with my airplane, the nose is automatically going down and I need to pull in the stick to maintain the nose on the horizon, thus level flight.
Why is that ?
This is NOT because of the increase in apparent weight (which is the vector sum of mv²/r + weight) because apparent weight applies at the Center of Gravity so its increased value does not affect the moment around the CG.
My hypothesis is that during the initial part of the turn I bank the aircraft. Then during the first seconds, a non symmetrical relative wind appears on the fin, generating a total reaction on the fin which is directed upwards and in the opposite direction of the turn. That aerodynamic reaction on the fin would create a moment nose down around the CG (and also a moment which will put the nose of the aircraft in the relative wind as a weather vane and re-establish a symmetrical airflow on each side of the longitudinal axis of the aircraft).
What do you think about that ?
Any other idea/opinion is more then welcome.
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Banking the a/c inclines the Lift..
the horziontal component of Lift causes the a/c to turn (centripetal force)
if the angle of attack is kept constant, the vertical component of Lift will be too small to balance the Weight of the a/c and the nose will drop.
the horziontal component of Lift causes the a/c to turn (centripetal force)
if the angle of attack is kept constant, the vertical component of Lift will be too small to balance the Weight of the a/c and the nose will drop.
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If you can remember back to your first flying lessons, the Effects of Controls, Roll causes Yaw and Yaw causes Roll.
The reason the nose begins to drop is because when you are in a turn the aircrafts keel (side) surfaces are exposed to the force of the air from the side that you are turning into. Because the COG is forward in the Aircraft the larger force is applied behind the COG therefore causing the Aircraft to Yaw into the turn which results in the nose dropping (i.e. Yawing into the turn) and if back pressure is not exerted on the stick to maintain level flight the result can be a Spiral Dive. Hope this helps.
The reason the nose begins to drop is because when you are in a turn the aircrafts keel (side) surfaces are exposed to the force of the air from the side that you are turning into. Because the COG is forward in the Aircraft the larger force is applied behind the COG therefore causing the Aircraft to Yaw into the turn which results in the nose dropping (i.e. Yawing into the turn) and if back pressure is not exerted on the stick to maintain level flight the result can be a Spiral Dive. Hope this helps.
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In simple terms :
- you bank the aircraft
- it starts slipping or falling sideways, into the direction of the bank
- you have a big tail fin sticking up at the back of the plane, which resists the sideways movement of the plane, so the nose falls into the turn more than the tail does
- therefore the nose drops.
- you bank the aircraft
- it starts slipping or falling sideways, into the direction of the bank
- you have a big tail fin sticking up at the back of the plane, which resists the sideways movement of the plane, so the nose falls into the turn more than the tail does
- therefore the nose drops.
