Helicopter "wobble"

[44HardCorps]

I've been fortunate enough to have travelled on many helicopters, having worked offshore for a lot of years.

 

On several occasions I have been onboard as the helicopter was started up from cold. On each occasion, during initial rotor movement, the helicopter would slightly "wobble" for a short time at initial start up. I guess this would be due to the centre of gravity shifting until the rotors are at the optimum RPM?

 

Due to its unique twin rotor system, is the same "wobble" a characteristic of the Ka-50?

[AussieFX]

I've been fortunate enough to have travelled on many helicopters, having worked offshore for a lot of years.

 

On several occasions I have been onboard as the helicopter was started up from cold. On each occasion, during initial rotor movement, the helicopter would slightly "wobble" for a short time at initial start up. I guess this would be due to the centre of gravity shifting until the rotors are at the optimum RPM?

 

Due to its unique twin rotor system, is the same "wobble" a characteristic of the Ka-50?

That's pretty much it, the rotor tips are weighted therefore the individual blades can be balanced. If you damage a blade they are usually replaced in matched sets.

[Yo-Yo]

I've been fortunate enough to have travelled on many helicopters, having worked offshore for a lot of years.

 

On several occasions I have been onboard as the helicopter was started up from cold. On each occasion, during initial rotor movement, the helicopter would slightly "wobble" for a short time at initial start up. I guess this would be due to the centre of gravity shifting until the rotors are at the optimum RPM?

 

Due to its unique twin rotor system, is the same "wobble" a characteristic of the Ka-50?

 

It could be a kind of "ground resonance" phenomena. The energy of starting engine can not wobble the helicopter up to dangerous magnitude due to the dampeners and resonant frequency values made dy design but you can notice this wobbling.

Ka-50 in RL has the dangerous area of rotor rps and this zone must be transient only.

The model in BS has the same "feature" so you can encountered GR after rough landing, etc.

[44HardCorps]

I think it would be nice to add this "wobble" to the sim.

[graywo1fg]

.... just have someone else in the house move your chair a little bit for some wobble :P or go crazy with your track IR :D

[Obiwan]

I think it would be nice to add this "wobble" to the sim.

 

If SHIFT-J isn't wobbly enough for you, you can always clip a blade on mission start :D

[AlphaOneSix]

I don't think this wobble, as you describe it, exists for the Ka-50.. What you describe sounds like something that I have very intimate knowledge of, namely that rotor systems that use hydraulic dampers for dampening of lead and lag forces on the rotor blades. When a helicopter that has hydraulic dampers sits for any length of time, the individual rotors tend to "hunt" for equilibrium while it sits static on the ground. When the rotors start turning again, the rotor disc is out of balance (some blades closer to each other, some farther away) for a few seconds until the rotor speeds up enough for the blades to find their proper place, so to speak. This wobble does not occur on helicopters that use elastomeric dampers, such as the Ka-50.