Hey,

why is the Rudder turning full to left when the Hydraulic Pumps are switched off ?

is that real behavior ?

 

 

 

is that real behavior ?

 

thanks Kyle

obviously :good:

thanks Kyle

obviously :good:

 

Welcome - as for the specific answer to the first question, I think that's a question for @EGLL77W...

No hydraulic pressure means the rudder moves in whatever direction the wind is blowing. or does it always go to left on the 777?

 

 

or does it always go to left on the 777?

 

Pretty sure it biases to the #1 side, but I could be wrong.

Kyle, how come you always have a picture ready for every situation and every question asked on this forum :lol:

Kyle, how come you always have a picture ready for every situation and every question asked on this forum :lol:

 

A little bit of this:

I like the photo

I bet it's because you depressurize the left system first per the FCOM "to avoid fluid transfer". So the right system still has pressure, which forces the rudder to the left. 

I bet it's because you depressurize the left system first per the FCOM "to avoid fluid transfer". So the right system still has pressure, which forces the rudder to the left.

I doubt that, otherwise wouldn't a left system failure lead to a rudder hard over?

I doubt that, otherwise wouldn't a left system failure lead to a rudder hard over?

Good point, although I imagine there would be a redundancy built in to protect against that happening in flight. When you're shutting down you've already lost the Engine driven hydraulics, and you then turn off the demand pumps on that side.. I don't know. I thought it was wind at first, but it always seems to go to the left.

One way to find out; depressurise the right side first. I'll try tomorrow.

When there is no hydraulic pressure in the system, the rudder will move to whatever side the wind is blowing against the rudder. No wind, the rudder will stay put. It is finely balanced that a breeze will push it in whatever direction it blows. 

 

Try it in the sim, slew the plane in different directions, un-slew and watch the rudder move to whichever side the wind blows ;-)

When there is no hydraulic pressure in the system, the rudder will move to whatever side the wind is blowing against the rudder. No wind, the rudder will stay put. It is finely balanced that a breeze will push it in whatever direction it blows. 

 

Try it in the sim, slew the plane in different directions, un-slew and watch the rudder move to whichever side the wind blows ;-)

 

Indeed. I'v seen plenty of screenies with it hard over the other direction too.