Right pedal authority

[AeriaGloria]

  Hello, I had a feeling after the last patch that something changed in regards to right pedal authority. It seems much more difficult to coordinate high power turns. The speed limit of being able to do a coordinated right hand turn is more limited by power. Becuase of this you cannot do much more then a 30 degree bank turn at 260 kmh cruise while staying coordinated. If you go a bit slower and use less power you can hit 45 degrees bank at 230 kmh and have enough right pedal to coordinate with dropping below critical main rotor RPM. A lot of the time; full right pedal is needed to reduce side slip, and still can’t fully coordinate. 
 

  Anyways, not sure if anything changed at all, or if something did change it was correct. I know there was some talk and patches lately about Apache tail rotor VRS from slight side slip at high speed. I do not know if that’s related.
 

  As it does definitely seem to do really well until right right slip starts, as soon as right slip starts it’s as if the tail rotor “loses grip” on the air. 
 

  Perhaps it’s always been this way and I just didn’t do enough right turns. Anyways, here’s a track if someone wants to take a look. I turned yaw autopilot off, turned off altitude channel to keep collective axis matched to my physical axis, and reset trim after turning off yaw AP. SPUU-52-3 is on as it would be in reality 

rightpedalauthority2.trk

Edited October 9, 2022 by AeriaGloria

[randomTOTEN]

I took over your track, and was able to achieve the following flight parameters, through multiple 360° continuous turns. It took several minutes of careful control to get here.

I'm pretty sure this scenario is over stressing the engines, as you're commanding takeoff EPR in the maneuver. So the concept that there's power lacking to perform this maneuver doesn't terribly surprise me. Is there any documentation that states what the requirements are?

[AeriaGloria]

8 hours ago, randomTOTEN said:

I took over your track, and was able to achieve the following flight parameters, through multiple 360° continuous turns. It took several minutes of careful control to get here.

I'm pretty sure this scenario is over stressing the engines, as you're commanding takeoff EPR in the maneuver. So the concept that there's power lacking to perform this maneuver doesn't terribly surprise me. Is there any documentation that states what the requirements are?

Yup, that 30-35 degree bank you can do is about max. 
 

Technically the 5 minute limit for take off power is to increase engine life time, it wouldn’t actually decrease power mid flight from being in max power a while. But yes in reality you would only go above cruise power for five minutes at a time, and at cruise power there is no issues staying coordinated. 
 

I have not seen any documentation or figures to say how much of a right turn you can do at cruise speed, I am merely curious as it “feels” different from before the patch.  But of course a feeling is subjective. 
 

I definitely mean this as more of a problem/curiosity and not a bug. If we get more authority I would love it, but if it’s working as intended I would also be very happy. 
 

Thank you for trying out the track! Sometimes I wish they made that vertical stabilizer produce a little more lift, or added a rudder like Ka-50

[randomTOTEN]

16 minutes ago, AeriaGloria said:

it wouldn’t actually decrease power mid flight from being in max power a while.

it would if you were respecting it (because you would be reducing engine power).

I don't really know what you're expecting here. 30 degrees of sustained turn is nothing to sneeze at. If you're already rocking along at "lol limits" power settings I don't know where you expect to find another 50% horsepower to pull anything more.

In my image my pedal isn't at the limit of travel. What actually limits my bank is the inability to maintain speed. And some roughness with my control inputs. Coordination is fine.

[AeriaGloria]

16 hours ago, randomTOTEN said:

it would if you were respecting it (because you would be reducing engine power).

I don't really know what you're expecting here. 30 degrees of sustained turn is nothing to sneeze at. If you're already rocking along at "lol limits" power settings I don't know where you expect to find another 50% horsepower to pull anything more.

In my image my pedal isn't at the limit of travel. What actually limits my bank is the inability to maintain speed. And some roughness with my control inputs. Coordination is fine.

Yes power was not really what I was wondering about, but if full right pedal is really supposed to do so little at cruise speed 

[AeriaGloria]

On 10/9/2022 at 6:16 PM, randomTOTEN said:

it would if you were respecting it (because you would be reducing engine power).

I don't really know what you're expecting here. 30 degrees of sustained turn is nothing to sneeze at. If you're already rocking along at "lol limits" power settings I don't know where you expect to find another 50% horsepower to pull anything more.

In my image my pedal isn't at the limit of travel. What actually limits my bank is the inability to maintain speed. And some roughness with my control inputs. Coordination is fine.

Pretty sure you’re right. I probably just never checked it in such depth before and was surprised it was more limited then I thought. Testing it in a variety of atmospheres and weights, yeah it does fly a lot more like normal then I thought. Wonder if I’ve just been overweight recently

[randomTOTEN]

From watching your track, I think through a variety of causes you had a droop in main rotor rpm. This I believe would also cause a drooping of tail rotor rpm, which you could interpret as a loss off yaw authority. At the end of your track (I believe, it's been a little bit now) you are simultaneously at full collective and full pedal.

Edited October 13, 2022 by randomTOTEN

[AeriaGloria]

18 minutes ago, randomTOTEN said:

From watching your track, I think through a variety of causes you had a droop in main rotor rpm. This I believe would also cause a drooping of tail rotor rpm, which you could interpret as a loss off yaw authority. At the end of your track (I believe, it's been a little bit now) you are simultaneously at full collective and full pedal.

 

Yeah, I’ve been trying figure out what power levels are low enough to allow to coordinate any right hand turn. And how much that depends on weight if it depends at all. It seems above 75-85% collective pitch, you cannot coordinate banking turns steeper then 30 degrees

At which point, you might go from 30% right pedal to full right pedal with little difference but rotor droop.
 

So yeah marked your first post as the solution, I just don’t think I had tried doing level right hand turns so steep before. If you’re diving you need less power, and have no problem coordinating even 60-80 degree bank angle turns at any speed  

[Tiger-II]

All helicopters have a better side to turn. It seems the Hind runs out of power, rotor RPM droops, and then you start getting other problems.

It's a big tail rotor that you're demanding a lot of pitch from, and I don't think the Hind has much excess power to deal with it.

[admiki]

51 minutes ago, Tiger-II said:

All helicopters have a better side to turn. It seems the Hind runs out of power, rotor RPM droops, and then you start getting other problems.

It's a big tail rotor that you're demanding a lot of pitch from, and I don't think the Hind has much excess power to deal with it.

It has enough power to do vertical take off about 650 kgs overweight at sea level, which is approx 5% over MAUW. You might crab a bit until you get some speed, but it can do it. Same goes for Mi-8 and to some extent Huey. Haven't flown Ka-50 or Gazelle. Apache is spot on on what it says on perf page.

[AeriaGloria]

1 hour ago, Tiger-II said:

All helicopters have a better side to turn. It seems the Hind runs out of power, rotor RPM droops, and then you start getting other problems.

It's a big tail rotor that you're demanding a lot of pitch from, and I don't think the Hind has much excess power to deal with it.

There is sweet spot for collective when making turn. Full pitch causes too much torque, needing high tail rotor drag. 
 

Highest pitch you can maintain full power and 90-95% rpm, since Governor cuts power above 95%. You can increase this limit by 2-3% with rpm adjust switch on collective. For me usually end up at 11-13 collective for 200-250 kmh right hand turn sustained 

SPUU-52 off won’t help much, Tail rotor stalls eventually, same if you let it crab more then about 10 degrees (slip ball 2/3rds right)

[admiki]

37 minutes ago, AeriaGloria said:

There is sweet spot for collective when making turn. Full pitch causes too much torque, needing high tail rotor drag. 
 

Highest pitch you can maintain full power and 90-95% rpm, since Governor cuts power above 95%. You can increase this limit by 2-3% with rpm adjust switch on collective. For me usually end up at 11-13 collective for 200-250 kmh right hand turn sustained 

SPUU-52 off won’t help much, Tail rotor stalls eventually, same if you let it crab more then about 10 degrees (slip ball 2/3rds right)

You rarely have to do more than 180 turn. That's why I like diving attacks. Get speed to 300, roll a lot and start pulling. Once it it starts to mush on you, drop some collective and it will turn for you on its own. I can exit hard right turn at about 240.

[Tiger-II]

I found a bigger problem was suffering RBS. I'm not sure why a 40 degree right turn would induce that?

[randomTOTEN]

Do you know how G's work?

[AeriaGloria]

5 hours ago, Tiger-II said:

I found a bigger problem was suffering RBS. I'm not sure why a 40 degree right turn would induce that?

It’s mushing. Caused by exceeding 1.8 G at low altitudes and medium weight. Only happens this has becuase wings stall from positive AOA, when their lift stalls it causes pitch up. This causes rotor to stall. Which makes pitch up even worse. 
 

Depending on where collective is, your horizontal stabilator will stall at around 10 degrees AOA or more. Once your stabilator stalls you are really screwed! 
 

So as preventative or to help you can decrease collective 1-3 degrees, watch your G meter, build up G slowly. At altitudes of 2,000-3000m your max g won’t be higher then about 1.4-1.5. And don’t be afraid to give full forward cyclic when you feel it starting. Decreasing collective will help un-stall the rotor blades and increase control, as well as rotating the stabilator down to make it work at higher AOA. 
 

This happens in any helicopter, but is only mentioned in army manuals becuase it usually happens in fast dives. But Mi-24 with its wings that are behind rotor causing 25% lift and pitch down, with 19 degrees incidence so they stall easily, and rotors that only have 3 degrees of washout/twist (many other helicopters like Apache and Mi-8 have rotor with 7-8 degrees twist), all mean that when your wings stall then your rotor stalls and you cobra. If your rotor stalls then your wing stalls after that and you cobra. 
 

This can be good for breaking, but once you get good at hearing and feeling when it happens, you will be able to ride the edge. 
 

In a level turn your bank angle decides your G. A 2 G turn is equal to 60 degree bank in level turn. So basically at low weight and altitude, 60 degree turn is the steepest turn you can do. 45 degree is about 1.4 G, so your range of max bank in level turn is about 45-60 degrees. 
 

You can ignore the relation between speed and max G, while speed does make the mushing more violent, if you can pull 2 G at 250 kmh you can do it at 300 kmh 

 

If You need to turn with more then 60 degrees of bank, plan on losing altitude 

Edited December 30, 2022 by AeriaGloria

[AeriaGloria]

13 hours ago, Tiger-II said:

I found a bigger problem was suffering RBS. I'm not sure why a 40 degree right turn would induce that?

Army fundamentals of flight https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN35749-TC_3-04.4-000-WEB-1.pdf

Described as 

“MUSHING
1-165. Mushing is a temporary stall condition occurring in helicopters when rapid aft cyclic is applied at high forward airspeeds. Normally associated with dive recoveries, which result in a significant loss of altitude, this phenomenon can also occur in a steep turn resulting in an increased turn radius. Mushing results during high G- maneuvers when at high forward airspeeds aft cyclic is abruptly applied. This results in a change in the airflow pattern on the rotor exacerbated by total lift area reduction as a result of rotor disc coning. Instead of an induced flow down through the rotor system, an upflow is introduced which results in a stall condition on portions of the entire rotor system. While this is a temporary condition (because in due time the upflow will dissipate and the stall will abate), the situation may become critical during low altitude recoveries or when maneuvering engagements require precise, tight turning radii. High aircraft gross weight and high density altitude are conditions conducive to and can aggravate mushing.
1-166. Mushing can be recognized by the aircraft failing to respond immediately but continuing on the same flight path as before the application of aft cyclic. Slight feedback and mushiness may be felt in the controls. When mushing occurs, the tendency is to pull more aft cyclic which prolongs stall and increases recovery times. Make a forward cyclic adjustment to recover from the mushing condition. This reduces the induced flow, improves the resultant AOA, and reduces rotor disc coning which increases the total lift area of the disc. The pilot will immediately feel a change in direction of the aircraft and increased forward momentum as the cyclic
  05 July 2022 TC 3-04.4 1-51

Chapter 1
 is moved forward. To avoid mushing, the pilot must use smooth and progressive application of the aft cyclic during high G-maneuvers such as dive recoveries and tight turns”

 

So as you can see, basically a helicopter stall that is made more violent and agreesive by the wing aerodynamics which brings to stall at positive AOA, and the little rotor twist. And once your stabilator stalls you’re really screwed. 
 

Now you know everything there is to know about mushing

If this isn’t what you were experiencing, please forgive me and give me some more details. There is a difference in return to level bank stability in left versus right turns 

Edited December 30, 2022 by AeriaGloria

[admiki]

58 minutes ago, AeriaGloria said:

Army fundamentals of flight https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN35749-TC_3-04.4-000-WEB-1.pdf

Described as 

“MUSHING
1-165. Mushing is a temporary stall condition occurring in helicopters when rapid aft cyclic is applied at high forward airspeeds. Normally associated with dive recoveries, which result in a significant loss of altitude, this phenomenon can also occur in a steep turn resulting in an increased turn radius. Mushing results during high G- maneuvers when at high forward airspeeds aft cyclic is abruptly applied. This results in a change in the airflow pattern on the rotor exacerbated by total lift area reduction as a result of rotor disc coning. Instead of an induced flow down through the rotor system, an upflow is introduced which results in a stall condition on portions of the entire rotor system. While this is a temporary condition (because in due time the upflow will dissipate and the stall will abate), the situation may become critical during low altitude recoveries or when maneuvering engagements require precise, tight turning radii. High aircraft gross weight and high density altitude are conditions conducive to and can aggravate mushing.
1-166. Mushing can be recognized by the aircraft failing to respond immediately but continuing on the same flight path as before the application of aft cyclic. Slight feedback and mushiness may be felt in the controls. When mushing occurs, the tendency is to pull more aft cyclic which prolongs stall and increases recovery times. Make a forward cyclic adjustment to recover from the mushing condition. This reduces the induced flow, improves the resultant AOA, and reduces rotor disc coning which increases the total lift area of the disc. The pilot will immediately feel a change in direction of the aircraft and increased forward momentum as the cyclic
  05 July 2022 TC 3-04.4 1-51

Chapter 1
 is moved forward. To avoid mushing, the pilot must use smooth and progressive application of the aft cyclic during high G-maneuvers such as dive recoveries and tight turns”

 

So as you can see, basically a helicopter stall that is made more violent and agreesive by the wing aerodynamics which brings to stall at positive AOA, and the little rotor twist. And once your stabilator stalls you’re really screwed. 
 

Now you know everything there is to know about mushing

If this isn’t what you were experiencing, please forgive me and give me some more details. There is a difference in return to level bank stability in left versus right turns 

 

there might be a condition where close to RBS, rolling to the right might increase AoA on right side just enough to stall it.

But, I too think he is experiencing mushing

 

[Tiger-II]

As @admiki said, I think that is the actual problem. I'm already on the margin, and exceeding it by turning at all.

Quote

when rapid aft cyclic is applied at high forward airspeeds

"rapid aft" means "to move quickly". I'm not doing that. I know you can't see me flying, but I'm actually very smooth on the controls, and I'm not pulling aft at all. Pure roll + pedal only.

Edited January 2, 2023 by Tiger-II

[AeriaGloria]

5 hours ago, Tiger-II said:

As @admiki said, I think that is the actual problem. I'm already on the margin, and exceeding it by turning at all.

"rapid aft" means "to move quickly". I'm not doing that. I know you can't see me flying, but I'm actually very smooth on the controls, and I'm not pulling aft at all. Pure roll + pedal only.

 

Yes. That’s becuase that’s the US Army definition that doesn’t operate it and only really experienced it in dives. 
 

But Mi-24 is very fast, easily mushes in level flight, and becuase of it’s wings this mushing is based on a G limit that varies on altitude. 

That’s all I can say, it’s not the exact same phenomenon that the US army describes for its wingless or helicopters with wings that aren’t designed quite the same. 
 

I was very surprised myself how accurately the G limit chart from the manual applies to DCS. 
 

I know by being careful with cyclic, I can do 2 G turns from 200-350 kmh, and sustain them especially long by doing so in a dive. It’s not like you can’t turn at high speed; just got to be careful with the Gs.

 

Maybe it’s easier for me since I use a jetseat with the G vibration turned up all the way so I feel it in my butt as well as having the G meter. But you will also be able to notice the sound of the rotors stalling and making a more aggressive FLAP FLAP FLAP noise as the coning becomes severe. So having your sound turned up can help as well. 
 

Sometimes I wish the precision air data vane was easier to see by the pilot, if you fly while looking at it or at looking at AOA in the F2/F10 bar also, the relation also becomes very clear 

[Tiger-II]

I wish you could see my flying. I completely agree with everything written. I just keep forgetting the thing has wings and their effect.

Happy New Year!

[AeriaGloria]

7 hours ago, Tiger-II said:

I wish you could see my flying. I completely agree with everything written. I just keep forgetting the thing has wings and their effect.

Happy New Year!

Also thought I would mention, becuase of gyroscopic precession, rolling right causes a pitch up and rolling left a pitch down. So a rapid roll right can actually induce mushing/wing/rotor-stall/over G. 
 

Heres what manual says, you can disregard how speed decreases max G, more speed makes mushing more violent but still happens at same G. The lower G for high speed I’m sure is there for Margin of safety 

Edited January 3, 2023 by AeriaGloria