Will a plane fly straight or turn away from it's cruising straight ahead attitude of flight , if you release the controls?
What does an airplane really want to do concerning the direction of its flight?
Unfortunately, aircraft built to American specifications don't have the stability to remain straight and level with the controls released.
A pilot knows this if he experiments at a safe altitude. Release the controls and the plane will enter a turn. Pilots say the reason a plane enters a turn is because of:
The end result, if the plane is left to its own fate, is the plane will break up in this tight corkscrew because of excessive g forces that exceed the aircrafts maximum load limits.
The spiral looks like a spin except the plane's controls will function in a normal manner and no stall is involved. You can recover from a spiral dive any time you elect to use the controls.
The entrance into a spiral begins when something disturbs the plane's right-left sense. The aircraft will respond to the disturbance in two different ways simultaneously. One is a planes vertical tail will yaw the plane around to point itself into the direction it was actually moving. At the same time its tendency to refuse to sideslip, due to the dihedral angle of its wings, will cause the plane to lift one wing and drop the other to regain its lateral balance. Both events occur together.
The turn causes the relative wind, to blow slightly crosswise at the plane to affect both the vertical tail and the wings dihedral at the same time. A plane will respond to a disturbance depending on weather the yaw effect or the wing-righting response is quicker and more forceful.
Think about a plane that has a very small tail and a pronounced dihedral. If a gust throws the ship into a slight sideslip the right wing will pick itself up before the small tail has a chance to yaw the plane around to the right. After the disturbance the plane will resume its flight in the origiinal direction.
Now think of a plane with no dihedral and a large vertical tail fin. The gust above will cause the plane to turn entirely from the yawing. If it does recover, it will head in a different direction.
Students think the vertical tail fin is there to keep the plane flying straight. Instead, it actually makes the plane turn.
All of the above also depends on tail length and wing span. The density of the air plays a role in the dampening effect. A gust may cause a quick response but the air density will damp the quickness. A short tail and short wings will react quickly. Slower for a long tail-long wingspan aircraft.
To a pilot, in a steep spiral turn, is that tendencies that exist in a plane with controls released will be noticeable when the pilot flies the turn.
Plane design should make stability a priority.
What does an airplane really want to do concerning the direction of its flight?
Unfortunately, aircraft built to American specifications don't have the stability to remain straight and level with the controls released.
A pilot knows this if he experiments at a safe altitude. Release the controls and the plane will enter a turn. Pilots say the reason a plane enters a turn is because of:
- Torque
- Stiff controls
- Wing heaviness
The end result, if the plane is left to its own fate, is the plane will break up in this tight corkscrew because of excessive g forces that exceed the aircrafts maximum load limits.
The spiral looks like a spin except the plane's controls will function in a normal manner and no stall is involved. You can recover from a spiral dive any time you elect to use the controls.
The entrance into a spiral begins when something disturbs the plane's right-left sense. The aircraft will respond to the disturbance in two different ways simultaneously. One is a planes vertical tail will yaw the plane around to point itself into the direction it was actually moving. At the same time its tendency to refuse to sideslip, due to the dihedral angle of its wings, will cause the plane to lift one wing and drop the other to regain its lateral balance. Both events occur together.
The turn causes the relative wind, to blow slightly crosswise at the plane to affect both the vertical tail and the wings dihedral at the same time. A plane will respond to a disturbance depending on weather the yaw effect or the wing-righting response is quicker and more forceful.
Think about a plane that has a very small tail and a pronounced dihedral. If a gust throws the ship into a slight sideslip the right wing will pick itself up before the small tail has a chance to yaw the plane around to the right. After the disturbance the plane will resume its flight in the origiinal direction.
Now think of a plane with no dihedral and a large vertical tail fin. The gust above will cause the plane to turn entirely from the yawing. If it does recover, it will head in a different direction.
Students think the vertical tail fin is there to keep the plane flying straight. Instead, it actually makes the plane turn.
All of the above also depends on tail length and wing span. The density of the air plays a role in the dampening effect. A gust may cause a quick response but the air density will damp the quickness. A short tail and short wings will react quickly. Slower for a long tail-long wingspan aircraft.
Designing a stable non-spiraling plane is not worth the time for aircraft designers. They design a plane to actually help a pilot in controlling the aircraft. They contend that a spirally stable airplane is hard to fly in rough air. It will tire the pilot out over a long period of time.
To a pilot, in a steep spiral turn, is that tendencies that exist in a plane with controls released will be noticeable when the pilot flies the turn.
Plane design should make stability a priority.
