Rudder problem only in flight

[branks737 29]

I updated to the latest pmdg 737ngx version via OC the other day (V1.20.8443) and was doing some testing today and discovered an issue with the rudder. Whilst taxing and during takeoff the rudder works as expected, however as soon as I'm in the air the rudder plays up. Whether I am pressing full rudder left or right, I will hold the rudder pedal down to one side for maximum deflection and the rudder would deflect for a fraction of a second then snap back to centre, even though I still have the rudder pedal hard left or right. 

Very strange as when I am back on the ground rudder works normally. I haven't changed anything apart from upgrading to the latest version via OC. Anyone else experiencing this??? by the way I am using it on P3DV4.

Regards

 

Branko Markovic

[branks737 29]

I now uninstalled the ngx and reinstalled the previous version (V.120.8413) and the same thing is occurring. I switched the yaw dumper to off and the rudder works normally in the air, what the hell???? I never used to do this in any version. I am at a loss am I missing something here??

 

[branks737 29]

ok seems to be working again after a reinstall of saitek drivers, then re calibrated axis's.

Something I did notice which never caught my attention before, was that when the aircraft is below 130kts (approx), I can get full deflection from the rudder. As I pass 130kts rudder deflection is almost decreased by half and the more airspeed I get the rudder deflection decreases further. Upwards of 300kts I barely get rudder deflection. Is this normal operation, is this simulating g-loads on the rudder?

[lodestar 186]

It's normal, all modern transport aircraft limit rudder deflection as airspeed increases

[JRBarrett 3,038]

7 hours ago, branks737 said:

ok seems to be working again after a reinstall of saitek drivers, then re calibrated axis's.

Something I did notice which never caught my attention before, was that when the aircraft is below 130kts (approx), I can get full deflection from the rudder. As I pass 130kts rudder deflection is almost decreased by half and the more airspeed I get the rudder deflection decreases further. Upwards of 300kts I barely get rudder deflection. Is this normal operation, is this simulating g-loads on the rudder?

That is exactly what is supposed to happen. The real aircraft limits the rudder travel with increasing speed. The rudder is the most aerodynamically powerful control surface on the airplane. If you DID manage to achieve full rudder deflection when the aircraft was flying at high speed,  it would most likely cause a complete structural failure of the vertical stabilizer.

Even at lower speeds, full rudder deflection on a large transport category aircraft can have a very bad result, as shown in the crash of American Airlines flight 587 in 2001.

https://en.m.wikipedia.org/wiki/American_Airlines_Flight_587

 

[branks737 29]

Yeah makes sense, thanks.