GFC500 YD Use

[V1VRV2]

I was wondering what there SOP is for the YD on the GFC500. When do you get it on and off?

[Niko182]

On usually maybe 20 to 30 seconds after takeoff. Off as part of the landing checklist. 

When I fly around for fun, like lazy 8s, or chandelles or other manuevers, for some stick and rudder flying, i'll also turn it off.

[donkaye]

In the light jets it is turned on almost immediately after takeoff after the gear is raised.  The AFMS says the YD is not to be used for takeoffs and landings.  It then says,

"Yaw Damper Engagement with Autopilot Off –- The yaw damper, if installed, may be engaged with the autopilot disengaged. This will provide yaw damping and turn coordination. YD will be annunciated in the autopilot status box."

So, like the light jets, I engage it after the gear and flaps are up on takeoff (Rudder trim is full right) even though the AP isn't engaged until 800' AGL.  After I level off in cruise, I disengage it, trim the rudder for coordinated flight, and then reengage the YD.  I feel this puts less stress on the YD Servo.  Except for landing, when I disengage the AP, I'll still keep the YD engaged.

[ArtVandelay]

I assume if you forget to turn it off on landing it would be noticeable or you can easily over power it?

[Niko182]

2 hours ago, ArtVandelay said:

I assume if you forget to turn it off on landing it would be noticeable or you can easily over power it?

For me it just turns off. However the YD annunciation on the G3X blinks red, therefor I added it to my checkflist.

[donkaye]

4 hours ago, ArtVandelay said:

I assume if you forget to turn it off on landing it would be noticeable or you can easily over power it?

"In tests" it is noticeable, but doesn't really interfere in any significant way with aircraft control--even in crosswind landings.  However, as stated in the AFMS, it should be off for landings.

Since it responds to "rate of change of rate of change" (the 2nd derivative in mathematical terms, lateral acceleration in layman's terms) among its 4 inputs (yaw rate, roll angle, lateral acceleration, and airspeed), it responds much better than a human in response to turbulence.  I've rested my feet on the rudder pedals during turbulence without any control input from me, and feel the immediate minute movements of the rudder to mitigate it.  For the small cost of adding it, it is worth every penny in my opinion.

[Niko182]

43 minutes ago, donkaye said:

For the small cost of adding it, it is worth every penny in my opinion

I agree. The people that havent flown with it dont know what they are missing out on. And although its movements are on the smaller side, the change it makes in turbulence makes a big difference, especially over time.

[Ragsf15e]

I fly a PA46T with the gfc600 for work.  I just turn on the full autopilot at an appropriate time after t/o.  I don’t do the YD by itself on departure.  Typically the AP remains engaged through the flight.  However, I’ll often disconnect the autopilot during descent to enter the pattern, but I reengage just the YD.  As others said, it’s nice in bumps, coordinates well and significantly dampens any tail wag (although Mooneys are pretty stable).  Mine automatically disengages at 200’agl, however I try to ensure it’s off at the 500’ callout on final,

[dzeleski]

I turn mine on at about 200ish feet. I pull the gear up immediately, YD, check airspeed, flaps up if fast enough.

I always hand fly my landings/approaches as much as possible so I just kick the whole AP off a few miles out and hand fly. If flying an approach to mins then leave everything on until your min and kick the AP off the YD will come off with it but ONLY if you use the disconnect button, if you press the AP button on the GMC it will leave the YD on.

[ArtVandelay]

For the small cost of adding it, it is worth every penny in my opinion.

Small cost is about $3500.
I avoid flying in turbulence so it’s benefit is somewhat limited for me.
But when I do install it I will tell them not to do anything that prevents easily adding it later.

[donkaye]

39 minutes ago, ArtVandelay said:

Small cost is about $3500.
I avoid flying in turbulence so it’s benefit is somewhat limited for me.
But when I do install it I will tell them not to do anything that prevents easily adding it later.

The servo costs about $1,275 (15% discount quoted),  Labor $2,000?  It sits right next to the Pitch Servo.  I think there are 4 wires.  Time to look for another installer.

[ArtVandelay]

The servo costs about $1,275 (15% discount quoted),  Labor $2,000?  It sits right next to the Pitch Servo.  I think there are 4 wires.  Time to look for another installer.

I pulled it from:
https://avionics-laf.com/products/garmin-gfc500-autopilot-installed

[Stanton R]

4 hours ago, donkaye said:

The servo costs about $1,275 (15% discount quoted),  Labor $2,000?  It sits right next to the Pitch Servo.  I think there are 4 wires.  Time to look for another installer.

The Yaw install kit including servo for a mooney is $2700 list, which assumes that you have the pitch tray.

 

[donkaye]

28 minutes ago, Stanton R said:

The Yaw install kit including servo for a mooney is $2700 list, which assumes that you have the pitch tray.

 

You're right, the YD Servo Kit was bid at $722.50.  So 722.50 + 1275 = 1997.50 in parts.  Still worth every penny.

[Z W]

Still learning and getting used to our GFC500.  I realized after landing the other day that I had done so with the YD on.  Didn't even notice until turning off the runway, although there was not a lot of cross-wind.  It appears to be a non-event, which is good design by Garmin I suppose.

Turning off the YD is going on my pre-landing checklist.  It is very easy to forget, since if you press the "AP" button on the control unit to disconnect the autopilot, the YD stays on.  As someone else said above, if you use the "AP Disconnect" button on the yoke instead, that turns off the YD as well.  I think I will make it my practice to always use the button on the yoke and not touch the AP button on the control panel, unless I make a conscious decision that I want the YD to stay on.  Coming from our old KAP150, there was no difference, and for no reason at all, I always used the control panel in the dash and not the button on the yoke.  I guess I have an old habit to break.

Edited July 13, 2021 by Zane Williams

[ArtVandelay]

Are the yoke buttons (YP, AP disconnect, CWS) required?

[donkaye]

1 hour ago, ArtVandelay said:

Are the yoke buttons (YP, AP disconnect, CWS) required?

Only the AP Disconnect Button is required on the yoke.  There is no CWS on the GFC 500, and there is no YD button in the yoke.

[kpaul]

14 hours ago, Zane Williams said:

Still learning and getting used to our GFC500.  I realized after landing the other day that I had done so with the YD on.  Didn't even notice until turning off the runway, although there was not a lot of cross-wind.  It appears to be a non-event, which is good design by Garmin I suppose.

Ha, I know a guy that may have landed a few different aircraft with the yaw damper engaged.  Seems to be a non-event in most cases.  Just don't try to do a 180 on a narrow runway with it engaged. Actually it doesn't work very well even on 150' wide ones.

In the PC-12 I use the 500' call-out to ensure the A/P & Yaw damper are disengaged.  My Mooneys GPS also calls out 500' so it is repeatable.  This assumes clear of clouds at 500'.  Otherwise, I wait until the runway is insight and landing is assured before mashing the disconnect button.