nightlynx Posted December 29, 2008 Share Posted December 29, 2008 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? Link to comment Share on other sites More sharing options...
ED Team Yo-Yo Posted December 29, 2008 ED Team Share Posted December 29, 2008 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. Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles. Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me Link to comment Share on other sites More sharing options...
airea Posted December 29, 2008 Share Posted December 29, 2008 What is ground resonance? Link to comment Share on other sites More sharing options...
slug88 Posted December 29, 2008 Share Posted December 29, 2008 What is ground resonance? http://en.wikipedia.org/wiki/Ground_resonance [sIGPIC][/sIGPIC] Link to comment Share on other sites More sharing options...
Airway Posted December 29, 2008 Share Posted December 29, 2008 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 Link to comment Share on other sites More sharing options...
ED Team Yo-Yo Posted December 29, 2008 ED Team Share Posted December 29, 2008 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. :) Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles. Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me Link to comment Share on other sites More sharing options...
Tango Posted December 29, 2008 Share Posted December 29, 2008 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. Link to comment Share on other sites More sharing options...
Airway Posted December 29, 2008 Share Posted December 29, 2008 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) Link to comment Share on other sites More sharing options...
REL Posted December 29, 2008 Share Posted December 29, 2008 Very interesting (=8 Link to comment Share on other sites More sharing options...
Tango Posted December 29, 2008 Share Posted December 29, 2008 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. Link to comment Share on other sites More sharing options...
Aser Posted December 29, 2008 Share Posted December 29, 2008 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 AW-139 Pilot Link to comment Share on other sites More sharing options...
ED Team Yo-Yo Posted December 29, 2008 ED Team Share Posted December 29, 2008 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. Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles. Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me Link to comment Share on other sites More sharing options...
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