Rudder Authority Issue

[j3ster1369 0]

Took the CRJ up for some hand flying out of KTTS. Once airborne I noticed it did not feel like i had any rudder authority. Plane did not even change heading. 

Switched to exterior view and the rudder is visibly deflecting left or right to full extent, but there is no effect on the flight path/aircraft in control movement. 

Is this a known issue that i did not see a post about already? 

I will try and record a video of it after i am no longer at work. 

 

Regards

Adam

[nordeichmole 0]

same problem here, unable to decrab in crosswind landings. visually it will fully deflect, which is also shown on the systems display pressing the fltctl-button. best regards, frank

[Hans Hartmann [OLD] 1419]

It simulates a RTLU (rudder travelling limiter unit) which reduces the rudder effectivity at higher speeds but that certainly shouldn't be the case during landings - unless you're way too fast.

[nordeichmole 0]

hello hans thanks for your quick reply! ok i was just playing around a bit, not beeing 'procedural' at all. lightly loaded around 130 kias above the threshhold of a 8000 ft runway should not be way off, though. at least i would expect to have some authority to align the longitudinal axis with the runway centerline, but i was unable. further on, i could not observe any yaw induced roll. best regards, frank

[j3ster1369 0]

I was across the numbers at 150kts indicated, not unreasonable of a speed. 

My day job is dispatching CRJ900s for a US carrier and 150kts is only

5-8kts faster than what i usually see with my crews in the real aircraft.

During jumpseat rides; full rudder authority is present at that speed.  

Is there a way to disable the RTLU and see if i notice a difference then

reactive the system and see if it replicates the issue?  

If you have any suggestions for ways to help you test this and provide 

any data or feedback i would be more than happy to get some flying

in to help solve it. Ill bring home a few flight plans so my weights 

and balances are in check to real world numbers. 

[Hans Hartmann [OLD] 1419]

I'll check the RTLU code and may be reduce the effect a bit.

[j3ster1369 0]

Thank you for looking into the issue Hans. 

I will still try to get some video of the instruments and indications 

on the flight deck so you can see speeds, heading, and rudder deflection. 

i wont have that ready until close to end of business your time, as I 

cannot get on my sim for a few more hours. 

[nordeichmole 0]

thank you for taking care of! just did some pattern flying again: when disengaging the yaw damper i´m able to make rudder inputs deliberatly, e.g. decrabbing in crosswind landings. is this the way the real a/c is operated? best regards, frank

[Hans Hartmann [OLD] 1419]

I think I was wrong about the RTLU. It limits the rudder travel to between 33 degrees at up to 200 kts and 4 degrees at 300 or more kts. So that is not the reason. However, it's possible that it's the yaw damper. Flightsim greatly reduces the rudder movement if that is switched on. It's too late for today to test that, but I'll give it a try tomorrow.

[norddeichmole 0]

much appreciated, thank you hans! regards, frank

[j3ster1369 0]

I did get to do some more patterns and got the same results as norddeichmole. If i disengaged the yaw dampers i regain rudder authority. Will be curious to see what you are able to see with some testing. For now ill just disengage the yaw damper as a workaround. 

 

Thanks Hans! Your dedication to the project is appreciated! 

[Jaas 8]

So I guess you have to disengage yaw dampers for landing.  That's why I couldn't steer the plane after landing on the runway with the rudder....

[norddeichmole 0]

hello hans, did you already manage to look into the rudder problem, could you replicate the findings? for me at least it feels very odd. i'm a bit surprised that only few people report about this. after all it's an essential flight control.... best regards, frank

[tturbo 0]

up!!! i ´m also waiting any clarification on rudder and yaw damper disconection,or not neccesary but need a fix in order to have yaw axis control on landings.

 

Pepe.

[ZaurisLJ25 2]

you shouldnt have to disengage the YD before landing or for ground steering since it steers thru the tiller(at least in the real thing).

so clearly something thats needs to be rectified.

[JRBarrett 675]

 

hello hans, did you already manage to look into the rudder problem, could you replicate the findings? for me at least it feels very odd. i'm a bit surprised that only few people report about this. after all it's an essential flight control.... best regards, frank

 

 

 

 

 

This problem must be something specific to particular end user installations. I've never had any issues at all with ground steering via the yaw axis during testing or in the release versions no matter whether the YD is on or off. (P3DV4). Perhaps it is a conflict with other add-ons, or something to do with the specific hardware controllers being used.

 

[norddeichmole 0]

it's not a matter of ground steering, that works well. it's about contolling yaw with the rudder. best regards, frank.

[j3ster1369 0]

5 hours ago, JRBarrett said:

 

 

 

 

 

 

 

 

This problem must be something specific to particular end user installations. I've never had any issues at all with ground steering via the yaw axis during testing or in the release versions no matter whether the YD is on or off. (P3DV4). Perhaps it is a conflict with other add-ons, or something to do with the specific hardware controllers being used.

 

for me it is just the rudder authority issue. I can steer just fine. 

The part i find most interesting is that although i have no rudder control when airborne 

with the yaw damper engaged, in the external view the rudder moves in full deflection 

to either side reflecting what input im giving with the rudder controls. 

Animation=correct.  Rudder flight dynamics=not accurate. 

[metzgergva 210]

Hello, 

I can offer an easy testing what you think would be a better rudder reaction:

Open the aircraft.cfg with notepad and search for the [flight-tuning] section.

Then edit this line to:

rudder_effectiveness        = 1.5 //1.0
This would mean 50% more efficiency of the rudder. Might be too much, but you can feedback what you think would be a better value.

Otherwise a video from testing this in a real flight or a sim session would be helpful to see the rudder deflection and the aircraft reaction.

 

[norddeichmole 0]

hello alexander thank you for joining into the disussion! i modified the .cfg as suggested but with no effect. the default values render a well balanced flight model as long as the yaw damper is not engaged. if engaged, the rudder seems to work correct (modelwise), meaning the pedals are fully kicked in, the rudder itself is fully deflected, which is also reflected on the eicas-display (showing maximum control movement). There is just no effect to the flight path. No yawing of the nose, no positive roll-moment. hence no chance to align the nose with the runway when approaching  with a crab angle in a crosswind landing. it seems as if the aerodynamic forces of the rudder are blocked by the yaw-damper. this behavior i can recall with some jetprops simulations. there you have to disengage the yaw damper for landing or in case of an engine failure immediately.

 

by the way i can not observe any difference with the skid/slip indicator on the pfd-display, whether the yaw-damper be engaged or not. in turns it stays centered - more or less. at least to a far greater extent than e,g, in single engine pistons like a skyhawk where you have to work the pedals constantly if you want to keep the ball centered halfway (it wont´t stay there in rough air anyway :-) i understand that this self-centering effect on fancy jet aircraft is achieved by the use of roll-spoilers which compensate for added drag of the down-going aileron. so maybe that´s the explanation why status of the yaw-damper system (which works only the rudder??) makes no difference in turn coordination?

 

maybe these observations help a bit. because otherwise beeing a simulation with excellent hand-flying characteristics i would be really, really nice if this issue could somehow be solved. thanks again and best regards, frank

[metzgergva 210]

I didn't catch that you had an issue only with yaw damper engaged. Will look into this.

[norddeichmole 0]

thank you, alexander! frank

[Hans Hartmann [OLD] 1419]

Alexander sent an update to the beta testers and is waiting for feedback from them.

[The Dude 6537]

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