Flight Model: Right Skid Low

[Zentaos]

First, I am really enjoying the Kiowa! Great job Polychop! It flies beautifully and, for the most part, is behaving how I expect.

 

However, I have a question about weight & balance, and translating tendency. I have been flying on Kola with a stripped down OH-58, no weapons, MMS removed, just to have fun flying the cleanest version I can set up. I am wondering if there is something causing the CG to be shifted to the right side of the helicopter, because it's hovering right skid low. When I set down, the right rear skid contacts first.

 

I have turned on the Controls Indicator while watching the track, and I have to input a little bit of left/aft cyclic while hovering, with left pedal to maintain heading. All of this is what I expect from a counter-clockwise rotor system, except that with all of these conditions, it should be hovering left skid low. I've never flown a Kiowa/Bell 407 in real life, but all of the different Robinsons I fly (R22/R44/R66) hover left skid low with the same inputs.

 

As you pick-up and increase left pedal to counter the torque, the tail rotor pushes you to the right (translating tendency) and you counter with left cyclic, which, while stationary, should leave the left skid low...Am I missing something about the CG of the aircraft that would cause this?...or is this an FM bug?OH-58_kola_03.trk

[LuseKofte]

I think this is realistic and how it should be. Listening to what real chopper pilots say this is how a chopper is. Casmo, a formar Kiowa pilot say you hoover with back down, sort of. Another pilot say that aerodynamic make lift on left side more than right side, so to recover a chopper it is always wise to use left turn

[Zentaos]

Thanks for the reply, but I'm not referring to the nose high attitude. That is normal for the type. I'm a licensed rotorcraft pilot in real life, so I'm not asking about the aerodynamics.

I follow Casmo and agree with his sentiments on the module and how realistic it is. What I was asking, was if there is something with the Kiowa, since I am unfamiliar with it in real life, that would cause it to be leaning the opposite direction of what it should be aerodynamically.

 

Kinkku responded to the same bug on Discord and confirmed that they are looking into it.

Edited June 28, 2024 by Zentaos

[Jel]

Yep it should be left skid down - not right.

Already thought i was seeing things - thanks for coming up with that.

 

There seems to be something odd about the skids anyway, considering friction. Unclear if those issues may be related but afaik devs are already looking into more details here so let´s see...

Edited July 8, 2024 by Jel

[Wrcknbckr]

Basically; for a counter rotating rotor the tail rotor thrust is directed to the right to counteract main rotor torque. To compensate drift to the right the only means is by gravity so the helicopter should be tilted to the left (which is then corrected by collective, cyclic, and pedal again and again, still hovering only...).

[Jel]

vor 58 Minuten schrieb Wrcknbckr:

Basically; for a counter rotating rotor the tail rotor thrust is directed to the right to counteract main rotor torque. To compensate drift to the right the only means is by gravity so the helicopter should be tilted to the left (which is then corrected by collective, cyclic, and pedal again and again, still hovering only...).

Yep, as mentioned above, it SHOULD be.

Since it isn´t, this issue waits to be adressed i guess.

[Hiob]

Some (most?) helicopters have the main rotor shaft tilted in a way, that gives optimal body attitude at cruise speeds. Which may lead to a crooked attitude in hover. Dunno if and how pronounced this effect may be in the kiowa. Maybe it is balanced differently for military use.

[Zentaos]

The main rotor is often canted for optimization in cruise. It depends on the design and how the engineers approach the different problems of rotor wing flight. However, It's nearly impossible to solve all of the different problems in each phase of flight so there are trade offs. Take the Huey for example, it's main rotor is canted 5° forward for cruise optimization, but in turn it hovers nose high. I don't know what the design solutions are in the Kiowa, but there is always a trade off. I would assume, dangerous I know, that it is optimized for cruise since that is where most flight time is spent. 

 

Anyway, the devs already confirmed that it should be left skid low, like other CCW helis. We'll have to wait and see how it gets addressed.