SDV-5000-OA damper effect on Yaw Autopilot

[AeriaGloria]

   Hello, this passage from Cold War museum manual for Mi-24D states that disabling the pedal dampener stops the Yaw Channel from exceeding its 18% limit by using the SDV-5000-OA pedal damper. 
 

   The re-addition of this Yaw Channel moving pedals by Damper to hold heading, which in DCS is modeled as auto trimming of pedals, is causing lots of confusion.

  I did not think this feature was important before, but it may help and also make our Mi-24P more realistic!!

   Currently turning off pedal damper only forces all Yaw AP functions to “off,” rather then just the “displacement mode” mentioned in this Cold War Musuem manual that we see in game aa auto trimming when yaw AP reaches its limit in Heading hold mode. 
 

  Yes this manual is for Mi-24D, but it also has addendums for V/P models, and D/V/P and Mi-35M all use same SAU-V-24/VUAP-1 Autopilot. I have found same evidence of pedal Damper switch interacting with Yaw channel in a 2006 Mi-35M manual with uses same AP and Pedals/dampener, but obviously can’t use that evidence here. Which is a shame becuase the Mi-35M added a crucial piece of information, to paraphrase it “in order to reduce “jerking” of the tail rotor pitch, when pedal damper is disabled, the Yaw AP enters stabilization/dampening mode, to decrease sudden changes in tail rotor pitch.” Which seems to say there is no “heading hold” mode at all when pedal dampener is disabled. But that the yaw AP in dampening mode takes the place of the hydraulic SDV-5000-OA dampener in reducing stress on tailboom/jerking of tail rotor pitch. 
 

As the automatic movement in heading hold is caused by the pedal dampener, it makes sense that turning off the pedal dampener would also disable it, as the pedal damper SDV-5000-OA is the only way for the Auto pilot to go from 18% to 100% authority
 

 

Edited October 9, 2022 by AeriaGloria

[TheLongShanks]

Bahmp

[Schlomo1933]

Bump

 

[TheLongShanks]

Bump

[AeriaGloria]

3 hours ago, TheLongShanks said:

Bump

Things haven’t changed. Yaw damper off forces yaw channel off, but not forcing it into stabilization/matching/dampening mode and turning off heading hold and auto trimming

[Schlomo1933]

Bump

[DeMonteur]

I asked Mi-24 pilots and damper function is horribly modelled in DCS it should damp the sudden change of pedal movement to softer to prevent dutch roll, no retrimming logical axis when it hits the autopilot heading hold limit.

[AeriaGloria]

22 minutes ago, DeMonteur said:

I asked Mi-24 pilots and damper function is horribly modelled in DCS it should damp the sudden change of pedal movement to softer to prevent dutch roll, no retrimming logical axis when it hits the autopilot heading hold limit.

the Cold War museum manual says it should re trim the pedals if the 18% authority is not enough and MicroSwitch disengaged. 

You mean if “pedal damper” red guarded switch is disengaged? Becuase if so then I believe it should only provide dampening regardless of MicroSwitch position. But it can definitly re trim your pedals with up to 100% authority of pedal damper engaged and yaw AP on, with microswitches released and heading changed more then 9 degrees 

[admiki]

1 hour ago, DeMonteur said:

I asked Mi-24 pilots and damper function is horribly modelled in DCS it should damp the sudden change of pedal movement to softer to prevent dutch roll, no retrimming logical axis when it hits the autopilot heading hold limit.

Strange, and I have Mi-24 pilot saying exactly the opposite thing

[DeMonteur]

15 minutes ago, admiki said:

Strange, and I have Mi-24 pilot saying exactly the opposite thing

Ok it was just chat at lunch. Maybe his meaning of function and mine thinking about it was different. What your sources say?

[admiki]

Exactly what AG said above. If heading hold is active (via microswitches) once servo limit is reached, system will move pedals. I don't know (didn't occur to me to ask) whether system will move pedals just enough to get servo back under limit or it will move pedals until servo has full authority (get servo in center).

[AeriaGloria]

6 hours ago, admiki said:

Exactly what AG said above. If heading hold is active (via microswitches) once servo limit is reached, system will move pedals. I don't know (didn't occur to me to ask) whether system will move pedals just enough to get servo back under limit or it will move pedals until servo has full authority (get servo in center).

The way it is in DCS Mi-8/24, it will stop moving pedals as soon as AP gets back within 18% limit. Which can be annoying as it will often move pedals in a seesaw motion on-off-on in an annoying way 

[sakoh36836]

 It is a Stability Augmentation System but not a control system (autopilot) per se. Some manufacturers incorrectly use the term. Check Here

[admiki]

2 hours ago, sakoh36836 said:

 It is a Stability Augmentation System but not a control system (autopilot) per se. Some manufacturers incorrectly use the term. Check Here

Why is your link taking us to seafood restaurant?

And no, SAS on Russian helicopter is a little bit more than just that. Pure SAS works as damper only, Russian system actively tries to get you back to trimmed position.

[AeriaGloria]

4 hours ago, sakoh36836 said:

 It is a Stability Augmentation System but not a control system (autopilot) per se. Some manufacturers incorrectly use the term. Check Here

You can fly it along different route, altitude, pitch, roll, all by manipulating AP panel and not touching stick or collective or pedals. I can also take off on hover and land that way. Only flight mode you can’t do is transition between Fast forward flight and hover. 

Is that not an autopilot? Actually, sometimes the attitude hold annoys me and I only want dampening