Ground resonance?

[nightlynx]

Sorry if this has been asked and answered else where but I was wondering if first, the KA-50 is affected by ground resonance and second if it's modeled in the sim?

[Yo-Yo]

Sorry if this has been asked and answered else where but I was wondering if first, the KA-50 is affected by ground resonance and second if it's modeled in the sim?

 

Real Ka-50 is not known suffering from GR... but as the vertical hinges are modelled there is a possibility to encounter GR if you shock the airframe while taxiing, for example. I do not know exactly what thing you have to bump because a building clips your rotor first... but if you can manage to find something for proper collision you can see the process.

By the way, when we removed damping from VFs we could see even "air resonance" - vibrations due to blades set CG moving after maneuvers in flight. It was a faded process for some seconds after the initial impulse.

[airea]

What is ground resonance?

[slug88]

What is ground resonance?

 

http://en.wikipedia.org/wiki/Ground_resonance

 

[Airway]

I have never thought that this can happen to a helicopter with inflated tires on a suspensioned gear

 

I would have thought suspension and tires absorb most of the resonance

 

Thanks for the video link

[Yo-Yo]

I have never thought that this can happen to a helicopter with inflated tires on a suspensioned gear

 

I would have thought suspension and tires absorb most of the resonance

 

 

No. they are the main reason of the resonance. :)

[Tango]

Someone posted a clip here of ground resonance occuring to a Bell with skids at the start of a TV program. The filming continued but you can see the pilot rush off the pad before the helicopter self-destructed.

 

I've managed ground resonance in BS by landing heavily.

 

Best regards,

Tango.

[Airway]

I saw that one - that was on the beginning of a MacGuyver series episode.

 

Is taking off always a solution to get out of this situation?

Or will these vibrations stay in the rotor system, making the shaft running "imbalanced"

(Don'T know how to describe)

[REL]

Very interesting (=8

[Tango]

Is taking off always a solution to get out of this situation?

It's the only solution. Take off or destroy the aircraft. You'd never get it shutdown quick enough to stop it.

 

Best regards,

Tango.

[Aser]

In fact you need to have a bad damper/strut/tire/etc to get into GR, helicopters needs to demonstrate they are GR free in good conditions.

 

No. they are the main reason of the resonance. :)

 

 

Regards

Aser

[Yo-Yo]

In fact you need to have a bad damper/strut/tire/etc to get into GR, helicopters needs to demonstrate they are GR free in good conditions.

 

 

 

 

Regards

Aser

 

Of course. But the point is that not BAD damper/strut/tire... not BAD but improper combination of their parameters can be the reason.