(Almost) Uncontrollable yawing to the left

[Avimimus]

7 hours ago, stuart666 said:

I never use the yaw channel personally, but ive had the spinning effect. I think it may well be VRS on the tail rotor. Hard opposite rudder and slightly reducing collective seems to fix it.

 

There is a video here which seems to explain its occurance. The Hind it seems, is very squirrely in wind.

 

 

 

Having watched the video - I'm pretty sure that is what is going on... I might even have been using one form of LTE to get into another form of LTE

[stuart666]

Glad its of interest.

 

Ive actually gone so far as to get the FAA Helicopter Flying Handbook, which has a lot of good stuff in it. You can download it for free off their website.

https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/

Edited June 29, 2021 by stuart666

[Rongor]

5 hours ago, Avimimus said:

 

could be some form of exotic VRS in level flight leading to a loss of tail rotor effectiveness

 

No and no.

There is no such thing like VRS in level flight. VRS is caused by a descend rate which drops you into your own downwash.

The only VRS in causing LTE would be a tailrotor VRS which also wouldn't happen during level flight.

Btw LTE generally might not matter that much during level cruise flight, since the wind vane effect keeps your helo pretty stable.

 

What you are describing may be some undesired steering input of the AP channels. I recall to have them put me into significant sideslip situations, which could very well be a factor for LTE, maybe even a tailrotor VRS.

 

There is no point in double tapping trim reset. It's just 2 times resetting your trim. If you experienced a need to trim reset to regain control, chances are high that there is a misunderstanding between you and your selected AP channels.

Edited June 29, 2021 by Rongor

[26-J39]

Personally i don't think LTE is being modeled, its just a "coding error" in the flight model, not necessarily a bug.

 

Just my speculation thats all.

[fargo007]

What's the loadout and takeoff weight?

 

Almost certainly you are overweight, and the helicopter doesn't have enough remaining torque to arrest the yaw rate when you're spinning to the left. 

 

With four rocket pods, two shturms and full fuel, you're at 108%. 

 

You would have to be down to under 10% fuel to get to a 100% MGTOW.  

 

In order to take off and fly that overweight, you would need to do a rolling TO, and your landing in such a condition would have to be equally careful. 

[nazradu]

2 hours ago, fargo007 said:

What's the loadout and takeoff weight?

 

Almost certainly you are overweight, and the helicopter doesn't have enough remaining torque to arrest the yaw rate when you're spinning to the left. 

 

With four rocket pods, two shturms and full fuel, you're at 108%. 

 

You would have to be down to under 10% fuel to get to a 100% MGTOW.  

 

In order to take off and fly that overweight, you would need to do a rolling TO, and your landing in such a condition would have to be equally careful. 

I managed to take off vertical at 108% multiple times. May be very hard at about 2500m ASL but so far it was not a huge problem.

[fargo007]

I'm not saying you cannot take off when overweight.  You can, but it requires extreme care. 

 

If people are yawing to the left and don't have enough right pedal to overcome the yaw rate, it's not a broken helicopter, it's that you're too heavy for the type of flying you are trying to do. 

 

The issue isn't a bug or anything like that...  It's simply that there's not enough torque available in the system at that weight people are trying to take off at.

 

To prove it, drop some weapons and reduce fuel so you are now under 100% MGTOW and try again. It will be a completely different experience.

 

 

[Stratos]

Can the Hind dump fuel in flight?

[Avimimus]

On 6/29/2021 at 3:14 PM, Rongor said:

No and no.

There is no such thing like VRS in level flight. VRS is caused by a descend rate which drops you into your own downwash.

The only VRS in causing LTE would be a tailrotor VRS which also wouldn't happen during level flight.

Btw LTE generally might not matter that much during level cruise flight, since the wind vane effect keeps your helo pretty stable.

 

What you are describing may be some undesired steering input of the AP channels. I recall to have them put me into significant sideslip situations, which could very well be a factor for LTE, maybe even a tailrotor VRS.

 

Hmm.... well, I don't have the AP yaw channel on - only the pitch damper... so I honestly don't think it can be the YAW AP which is doing it! No one to blame but me

 

 

On 7/1/2021 at 9:40 AM, fargo007 said:

What's the loadout and takeoff weight?

 

Almost certainly you are overweight, and the helicopter doesn't have enough remaining torque to arrest the yaw rate when you're spinning to the left. 

 

Yes, this is definitely the case. Sometimes I'll have it lower - but often I forget to reduce the amount of fuel!