You and your Hind - Basic Tutorial Videos

[Wrcknbckr]

1 hour ago, Lurker said:

 

Wait what? The net vector result of tailrotor thrust vs gyroscopic forces on the helicopter should be 0. There should be no inherent sideslip from tailrotor thrust. 

 

There is a torque balance yes, but no force balance. The helicopter can compensate by a small bank angle to compensate drift. This changes the complete force/moment balance that may also include a sideslip. I'm not sure how a 'normal flight' is conducted; accepting a sideslip or bank angle, probably both...

[admiki]

2 hours ago, Lurker said:

 

Wait what? The net vector result of tailrotor thrust vs gyroscopic forces on the helicopter should be 0. There should be no inherent sideslip from tailrotor thrust. 

 

It's called translational tendency.

Let's say you are in stable hover where disc is perfectly level. Rotor torque wants to spin helicopter around the mast. Just that, no other force vector. Tail rotor counteracts that by pushing on the tail. While it cancels torque, that push on the tail wants to push complete helicopter in that direction. If you look at hovering helicopter in no wind condition, it will hover with one side low, to compensate for that.  There is even a torque reaction created by tailrotor which needs to be canceled by cyclic.

Even if you have tail fin to unload tail rotor in forward flight, it still creates that side push. Now, if you do not compensate, either by inbuilt mast tilt or by tilting the disc via cyclic, it will create drift

[Lurker]

On 8/27/2021 at 4:46 PM, admiki said:

It's called translational tendency.

Let's say you are in stable hover where disc is perfectly level. Rotor torque wants to spin helicopter around the mast. Just that, no other force vector. Tail rotor counteracts that by pushing on the tail. While it cancels torque, that push on the tail wants to push complete helicopter in that direction. If you look at hovering helicopter in no wind condition, it will hover with one side low, to compensate for that.  There is even a torque reaction created by tailrotor which needs to be canceled by cyclic.

Even if you have tail fin to unload tail rotor in forward flight, it still creates that side push. Now, if you do not compensate, either by inbuilt mast tilt or by tilting the disc via cyclic, it will create drift

 

Oh okay, I see what you mean now. Thanks. But isn't that solved via Mast tilt? 

Edited August 30, 2021 by Lurker

[admiki]

11 hours ago, Lurker said:

 

Oh okay, I see what you mean now. Thanks. But isn't that solved via Mast tilt? 

 

Mast tilt is usually set to provide level cabin in forward flight (largest portion of flight time). There might be some mast tilt to compensate for translational tendency, but I don't know about that.