Garmin GFC500

[Rmag]

On my M20J it does not keep the ball centered on climb, it isn’t rudder trim.  It’s more like a shock absorber to dampen turbulence on the yaw axis. 

[Ragsf15e]

29 minutes ago, Rmag said:

On my M20J it does not keep the ball centered on climb, it isn’t rudder trim.  It’s more like a shock absorber to dampen turbulence on the yaw axis. 

How does it do on the descent?  I usually have to hold left rudder (3 blade prop might exaggerate that), but less than right rudder climbing.

 

[donkaye]

18 minutes ago, Ragsf15e said:

How does it do on the descent?  I usually have to hold left rudder (3 blade prop might exaggerate that), but less than right rudder climbing.

 

For me, the same as above.  Disconnect YD, adjust left rudder for a centered ball, then reconnect the YD.

[kpaul]

15 hours ago, aviatoreb said:

That's interesting.  But you have electric trim.  I do not.  I wonder if the GFC500 YD acts like trim keeping the ball centered without needing to manually stand on the rudder with my leg which while they are big and burly and wonderful legs, climbing for 10 or 15 min does take some devotion.

That is exactly what it does.  I can climb out with my feet off the rudders and the ball is centered.  When altitude is captured and the plane accelerates, the ball is still centered.

I fly a M20F with 2xG5s and GFC500.

[Wes]

Exactly

[aviatoreb]

2 hours ago, kpaul said:

That is exactly what it does.  I can climb out with my feet off the rudders and the ball is centered.  When altitude is captured and the plane accelerates, the ball is still centered.

I fly a M20F with 2xG5s and GFC500.

Wow - that a lone makes it worth the price of admission in that extra servo in my opinion.

[LANCECASPER]

My fear that using it as rudder trim would overwork the servo since that's not its purpose. If I had a YD w/o rudder trim I'd be keeping the ball centered in climb with my right foot to avoid replacing servos any more often than necessary.

[donkaye]

18 minutes ago, LANCECASPER said:

My fear that using it as rudder trim would overwork the servo since that's not its purpose. If I had a YD w/o rudder trim I'd be keeping the ball centered in climb with my right foot to avoid replacing servos any more often than necessary.

I agree.  I  think treating the YD as a rudder trim puts excess stress on the servo.  The long body Mooney clearly shows that the servo is not strong enough to handle acting as a rudder trim.

[aviatoreb]

2 hours ago, LANCECASPER said:

My fear that using it as rudder trim would overwork the servo since that's not its purpose. If I had a YD w/o rudder trim I'd be keeping the ball centered in climb with my right foot to avoid replacing servos any more often than necessary.

Darn- so much for my idea to lighten the load on my poor leg.

[kpaul]

2 hours ago, LANCECASPER said:

My fear that using it as rudder trim would overwork the servo since that's not its purpose. If I had a YD w/o rudder trim I'd be keeping the ball centered in climb with my right foot to avoid replacing servos any more often than necessary.

Well since my GFC500 was Garmin factory installed and that is how both the engineers and test pilots told me how to use it, I think I will continue to fly it that way.

I can also say that I have not had any of the issues that many others have.  I would have to assume that some of these problems are installation issues.

[LANCECASPER]

8 minutes ago, kpaul said:

Well since my GFC500 was Garmin factory installed and that is how both the engineers and test pilots told me how to use it, I think I will continue to fly it that way.

It's your airplane, you can fly it the way you decide. It sounds like a great plan as long as Garmin stands by the engineer's and test pilot's recommendations by giving you a written lifetime unconditional parts and labor warranty on that servo. My experience has been that owners have the privilege of opening their wallets much more often than company engineers and test pilots do. I hope you never have to replace that servo, but time will tell.

[dzeleski]

I engage my YD on climb as well. Keeps the ball centered in all phases of flight. I only have about 100 hours on it but the YD has been on for most of those hours. No issues so far but 100 hours isnt very much.

[carusoam]

Let’s consider how much harder a rudder trim servo motor works when used to center the ball during the climb…

 

1) Instead of working a range around the center…

2) in climb/descent… it now works the same range around an offset… (offset usually provided by rudder trim)

3) If the offset +/- the required range fits into the servo’s complete range… it won’t be working any harder….

4) What happens if the rudder servo runs out of range?  Bump the end, recognize the excess load, give warning, fail, and turn off….(?)

 

Why this isn’t a feature is a bit concerning….

my KAP150 has an elevator servo, and elevator trim servo…

I would expect it would have a rudder servo and a rudder trim servo as well…

 

With modern servos, it may be possible to do the job with one servo… one human arm seems to work fairly well… 

PP thoughts only, rudder trim is a nice feature… For long ascents and descents…

See if @TrekLawler stops by to explain the depth, value and limitations of the yaw damper…

Best regards,

-a-

[Wes]

Like kpaul... mine was also installed by Garmin....and tested and certified by Garmin. As per Garmin representatives,  YD after takeoff during climb was normal OP. Each to their own, but mine works flawlessly.

[FlyingDude]

I just installed mine last Nov-Jan time frame.  You need to dump your cash on multiple line items: head unit (507) + servos (gsa28s) + mooney installation kit (comes with the capstans for servos, pulley cables, weirdly shaped servo-holder brackets, label stickers, AP disconnect button, Go-around button, connector kits for gsa28 and 507), and then, you need to read the final 3-4 pages of the installation drawings that contain parts list.  There are two tables, one for parts that are included and one for those NOT included.  Those not included, you gotta order them from spruce, etc.  The not included parts are stuff like AN bolts, lock nuts, washers, spacers, pulleys, etc. etc.  which honestly, I believe would cost a lot more if they were stored, mix&matched and mailed by the Big G as opposed to Spruce, given big G's price scheme.

So, no, you don't cut one check to get one xmas present.

 

[Bob R]

Hey all,

Does anyone know if the GFC500 can use my existing electric Aerotrim trim as opposed to having to purchase the trim option for an additional $2500?

[Niko182]

On 5/10/2022 at 3:26 PM, aviatoreb said:

That's interesting.  But you have electric trim.  I do not.  I wonder if the GFC500 YD acts like trim keeping the ball centered without needing to manually stand on the rudder with my leg which while they are big and burly and wonderful legs, climbing for 10 or 15 min does take some devotion.

Mine does not center the ball. I still need rudder. In my experience its not a rudder trim. It is a yaw damper. It makes a hell of a difference having it and not. I didn't have a YD for about 2 or 3 months since i wasn't able to make it to the shop and have it replaced. Those 2 or 3 months were very noticably different. The yaw damper is 100% worth the price. It might also not center the ball on mine because i have 310hp. So different than the F model that states it centers it.

[ArtVandelay]

Hey all,
Does anyone know if the GFC500 can use my existing electric Aerotrim trim as opposed to having to purchase the trim option for an additional $2500?

Not if you want to use the autotrim feature, but you can still use your electric time manually, but it won’t connect to the 500.

[PT20J]

19 minutes ago, Bob R said:

Hey all,

Does anyone know if the GFC500 can use my existing electric Aerotrim trim as opposed to having to purchase the trim option for an additional $2500?

 

2 minutes ago, ArtVandelay said:

Not if you want to use the autotrim feature, but you can still use your electric time manually, but it won’t connect to the 500.

To elaborate, you would install the GFC 500 without the trim servo and it will annunciate TRIM UP or TRIM DOWN on the PFD and you would then have to adjust the trim with your existing trim system.

[ArtVandelay]

The yaw damper is 100% worth the price.

That maybe true for long bodies, the mid bodies don’t yaw that much IMHO.

[Niko182]

13 minutes ago, ArtVandelay said:

That maybe true for long bodies, the mid bodies don’t yaw that much IMHO.

The long bodies don't either. I think if you use it for 2 years, and then don't have it for 2 months, you really know what you're missing. Especially in turbulence. That's where the difference is massive.

[Aerodon]

I flew a C172 with GFC500 without pitch trim.  It would alert you when needing to trim up or down, and I can tell you that it does not need much adjustment each time.  So its clear that Garmin does not want the elevator servo working too hard, so I would apply the same logic to the rudder.

Yes I would like the YD to hold the ball in the centre during the climb, but that could be 15 or 20 minutes with fair amount of force.  I'll stick with the leg.

And the 'Aerotrim' rudder trim would solve this problem, but I think it looks rather home made.

 

Aerodon

 

 

 

[KLudwick]

Hi Bob, I own a 1971 E model and have a GFC 500 installed.  I also happen to work for Garmin.  Happy to answer any questions you may have about your upgrade!  kyle.ludwick@garmin.com works best.

[Fly Boomer]

11 hours ago, KLudwick said:

Happy to answer any questions you may have about your upgrade!

Response for @Bob R