What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Rudder malfunction???

mturnerb

Well Known Member
So today the "genius" operator of my aircraft learned something new. I did my usual pre-flight and started up the airplane. On the taxiway by my hangar (stopped and holding brakes) I did part of the checklist that I don't like to do in the run-up area as the airport is crazy busy on a beautiful VFR day like today. One of those items is an autopilot test (G3X touch) to check that I can overcome the servos and that my red button (autopilot disconnect) works as it's supposed to. So far, so good. My next action is always to turn off the flight director as the G3X autopilot leaves it on and I find it annoying while taxiing. Today I forgot to hit that button until a bit farther down the taxiway.

As I approached the point on the taxiway where I usually contact ground control (they have no visual contact with hangar area taxiways), I noticed that my rudder pedals felt "stuck": gentle force against the pedals gave me the sensation that the cables were caught/trapped. Strange, since I checked them on preflight and they seemed fine, and felt good when I got in the airplane to start up.

So I called up ground control and taxied back to my hangar using brakes. As I turned on the taxiway to my hangar I turned off the avionics and autopilot switches. Suddenly, rudder pedals are "free and correct". It's about this point that I realize I hit the yaw damper button instead of the flight director button (or both, not sure). Yaw damper servo engaged on the ground pretty much feels like a stuck rudder cable, I learned today!

It was a perfect day for the flight that then ensued after shutting down, checking everything on the ground fully, and making my way back to the starting point....
 
Last edited:
That is super good to know.

I haven't been doing any G3X checklists. Would you be able to send me what you have so I can add to my checklist?

Thanks,
D
 
That is super good to know.

I haven't been doing any G3X checklists. Would you be able to send me what you have so I can add to my checklist?

Thanks,
D

I modified mine from E's checklist on his blog/website - his are so good, I didn't see much room for improvement - I just modified where my airplane is different and deleted some non-relevant items. Not specific to G3X, just testing autopilot/autopilot disconnect. Here's where I found what he did:

https://rv-14a.blogspot.com/2017/10/first-flight-prep-my-poh-checklist-and.html
 
I modified mine from E's checklist on his blog/website - his are so good, I didn't see much room for improvement - I just modified where my airplane is different and deleted some non-relevant items.

I've been planning to do the same thing for awhile now - time to get to it with the first flight pending in (hopefully!) under three weeks...
 
On my RV-9A (no rudder servo, but I'd love to have a yaw damper), I've got the autopilot servos on a circuit breaker switch so that I can turn them off quickly if I should ever have to. I'll lose the nice variable speed electric pitch trim, but at that point, who cares...

I'm not concerned that the servo clutches and motor will abruptly get hard to overpower, so I don't test them every flight.

Our mileage differs, obviously...
 
On my RV-9A (no rudder servo, but I'd love to have a yaw damper), I've got the autopilot servos on a circuit breaker switch so that I can turn them off quickly if I should ever have to. I'll lose the nice variable speed electric pitch trim, but at that point, who cares...

I'm not concerned that the servo clutches and motor will abruptly get hard to overpower, so I don't test them every flight.

Our mileage differs, obviously...

I mainly test to assure autopilot disconnect function - since that button's on the stick, it's easy to test servo clutches at the same time. Old habit from Bonanza flying days.
 
Checklist???

Wow, thanks for posting. Brought back a stressful memory! I have the G3x touch and Garmin autopilot as well. First time happened to me several years back, in the run up area, in a hurry, on a X-C, busy airport and I have all this resistance in the flight controls...WTH!!! Did I pack something somehow that was restricting the flight controls??? I can't imagine how? Getting ready to call ground to taxi back and decided I would run my CHECKLIST...shocker.... "Auto Pilot/FD - Disengage" Press the button on the stick and now "Flight Controls - Free & Correct". The morale to this for me was as simple as these RV's can be you should ALWAYS do your checklist! Procedure, Procedure, Procedure. Every time I haven't or got distracted it has done nothing but add stress to my flying - totally unnecessarily!

Thanks for posting - Flight control resistance gets your attention real quick!
 
Back
Top