Passing through 100knots….

[RuskyV]

I have noticed with the SCAS system as you pass through 100knots bunting the cyclic forwards starts to induce a role to the left as the nose dips, this becomes very twitchy beyond 120knots, with anything over 130knots you start to loose the roll authority to counter this phenomenon, This might well be correct behaviour of course.
 

If the trimmer switch is held to desaturate the SCAS while at these speeds it will start to roll, cycling from left to right. Anything at or below 100knots is fine.

[frostycab]

I don't notice it until I'm pushing 120, but given the direction of rotation of the main rotor I assumed it could be down to retreating blade stall. 

Calling all knowledgeable people! Enlighten me!!!

[Swift.]

It sounds quite slow for retreating blade stall, doesnt it? 

[frostycab]

24 minutes ago, Swift. said:

It sounds quite slow for retreating blade stall, doesnt it? 

It does a bit. It only starts to get bad at 135ish. Perhaps RBS was the wrong term. What I was trying to suggest is that at higher speeds my limited knowledge of physics suggests to me that there will at some point be a perceivable lift imbalance, evidenced by OP saying that the roll always seems to begin towards the retreating blade side. 

[NeMoGas]

Pretty sure this was reported with one of the SMEs here saying it was incorrect.

[River]

Yep, at higher speeds it starts to roll and is quite hard to get out of that roll to one side movement. 

Edited April 8, 2022 by River

[admiki]

1 hour ago, River said:

Yep, at higher speeds it starts to roll and is quite hard to get out of that roll to one side movement. 

 

Reduce collective, it will reduce blade attack angle and get you out of RBS

[NeMoGas]

https://forum.dcs.world/topic/296266-acft-roll-characteristics/

[bradmick]

3 hours ago, admiki said:

Reduce collective, it will reduce blade attack angle and get you out of RBS

At 100knots you are nowhere near RBS. That doesn’t become a concern until about 180+ knots or so. If you’re at high speed and push forward cyclic the aircraft just floats vertically, but I won’t belabor the point, it’s already been reported. 

Edited April 8, 2022 by bradmick

[RuskyV]

Thanks for the reply’s, at least it’s a know phenomenon with the flight model. I can work around it easy enough for the time being.

[admiki]

17 hours ago, bradmick said:

At 100knots you are nowhere near RBS. That doesn’t become a concern until about 180+ knots or so. If you’re at high speed and push forward cyclic the aircraft just floats vertically, but I won’t belabor the point, it’s already been reported. 

 

I agree, I was just responding to comment that it is hard to get out of rolling tendency