Adding electric pitch trim and yaw damp to an existing GFC500 installation

[ArrowBerry]

Hey all,

We're slowly gathering information regarding a panel upgrade in our 1967 E which includes radio(s), and an AP. Our most recent question is regarding the extra cost of electric trim and yaw damp. While there's no question as to the added benefit of these systems, how hard are they to add after? If one was low on budget and went ahead with a very basic installation, can these features be added in years down the line to spread out the cost? Or is it a lot of work, and therefore expensive and not worth splitting up...aka, just close your eyes and spend the extra money when you put it in? 

[ArtVandelay]

The servos are just daisy chain connected to a CAN bus, assuming they can share power and servos there would not need any additional wiring, should be easy as they’re all installed in tail on the same mounting bracket IIRC.

[Pinecone]

I would think that you would want to have the shop do any wiring required when the install the basic system.  

[LANCECASPER]

On 5/11/2023 at 3:34 PM, ArrowBerry said:

Hey all,

We're slowly gathering information regarding a panel upgrade in our 1967 E which includes radio(s), and an AP. Our most recent question is regarding the extra cost of electric trim and yaw damp. While there's no question as to the added benefit of these systems, how hard are they to add after? If one was low on budget and went ahead with a very basic installation, can these features be added in years down the line to spread out the cost? Or is it a lot of work, and therefore expensive and not worth splitting up...aka, just close your eyes and spend the extra money when you put it in? 

It's going to be less money to do it all together rather than splitting it up. Plus, as much fine tuning is needed with this installation to get everything right, I'd want one person responsible.

[Yourpilotincommand]

I’d say the yaw damper is just adding unnecessary weight and cost in my opinion. More right rudder!! Lol. The trim servo I was told by an avionics shop is necessary for the GFC500 because the trim alert is constantly annoying. Do you have the annoying alert issue? ..or is there a way to suppress it? Or are they trying to upsell me to buying the trim servo?

[Fly Boomer]

Not only do you not need all that extra stuff — you don’t even need an autopilot.

[ArtVandelay]

Not only do you not need all that extra stuff — you don’t even need an autopilot.

Speak for yourself, on any trip longer than a hour, I need a working autopilot.

[kortopates]

Not only do you not need all that extra stuff — you don’t even need an autopilot.

VFR pilots may not but IFR pilots sure appreciate an autopilot.

Skipping electric trim makes no sense IMO. It barely works in a C172, but the Trim Up and Trim Down annunciations would be beyond annoying and i expect harder on your trim servo.


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[ArtVandelay]

My philosophy is either the autopilot flies the plane or I do. And trim is included, allowing hands off.

[pirate]

I added everything right away with no regrets but my advice to anyone is before you decide wether or not to add or delete durning the GFC500 do your self a HUGE favor and try to fly something with everything included.

During the flight you can  turn off the items you want for the demonstration and compare, do this on a smoother day and a very bumpy day then decide what works for you. 

 

[Pinecone]

It is funny.  Most everyone who HAS a yaw damper installed says everyone should install it.  The ones who say it is not needed, don't have it.

My 252 will get some serious tail wag in turbulence.  Judicious use of rudder solves the issue, but on a longer flight, that would be annoying.

All that, prior to buying my 252 I had maybe 15 minutes of flight time with autopilot on.  Most planes I flew (including jets in the military) did not have one.  And the few GA planes I flew with them, had a simple wing leveler.  

And yes, I hand flew a good bit of actual instrument.

[ArrowBerry]

I have flown a C182 without electric trim and completely agree, the constant messages requiring trim are annoying. One more thing blinking at you and needing attention during a potentially high workload time. 

I'm not debating the need for it, more looking from an installation and financial perspective as whether the initial AP installation can be completed without electric trim--fly for a year, and then add the trim at the next annual, for example. 

[kortopates]

I have flown a C182 without electric trim and completely agree, the constant messages requiring trim are annoying. One more thing blinking at you and needing attention during a potentially high workload time. 
I'm not debating the need for it, more looking from an installation and financial perspective as whether the initial AP installation can be completed without electric trim--fly for a year, and then add the trim at the next annual, for example. 

I’d say your tolerance will be proportional to how much instrument flying you do. I do some instruction in a couple of Cessna’s without it and it becomes beyond annoying without the electric trim and when you fail to heed the annunciation to trim up and down the AP stops climbing or descending till you fix trim. Not a big deal VFR but really adds to the workload of an already task saturated instrument pilot on an approach.


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[ArtVandelay]

I do some instruction in a couple of Cessna’s without it and it becomes beyond annoying without the electric trim and when you fail to heed the annunciation to trim up and down the AP stops climbing or descending till you fix trim.

I would think that’s hard on the servos as well.

[hubcap]

On 5/26/2023 at 3:35 AM, Pinecone said:

It is funny.  Most everyone who HAS a yaw damper installed says everyone should install it.  The ones who say it is not needed, don't have it.

My 252 will get some serious tail wag in turbulence.  Judicious use of rudder solves the issue, but on a longer flight, that would be annoying.

I don’t have it, and I certainly do not miss it. I have never noticed tail wag in my K Model, but I have never ridden in the back. I would definitely want electric trim. I can’t imagine flying without it.

[Pinecone]

Many people do not notice tail wag.  I find those with tailwheel and/or glider time notice it more.

I used to a fly a lot with a friend in a Cherokee 180D he was in a partnership on.  One day we are flying along, and he started cussing under his breath.  I asked what was the matter.  He says, "Damn you, you fly my airplane 4 knots faster at the same power setting."  The difference was, I was using the rudders to stop the tail wag.

But again, you make my point.  Those without YD, see no reason for it.  I don't think I have seen a single post by someone who installed it and said, "that was a waste of money."

[PT20J]

There is no doubt that a yaw damper will improve the dynamics of the airplane. Some airplanes have more Dutch roll than others. (it is not possible to have the tail wag only because the airplane will have a yaw-roll coupling). So, it's a matter of degree. The tradeoff for me is that you add both operational complexity (you have to turn it on and off) and system complexity (now you have another thing that can fail). My primary goal when I upgraded my avionics was to improve reliability, so I didn't add anything I didn't need.

You can add the electric trim later, but there is wiring for the MET switch on the yoke and it's associated circuit breaker in addition to installing the servo and wiring it. A local flight school installed a G3X and GFC 500 in one of the C-172s without the trim servo and everyone hated it so they went back and added it.

[hais]

Makes one wonder, between the A/P and the pilot, who is in charge and who is commanding whom

[PT20J]

1 hour ago, hais said:

Makes one wonder, between the A/P and the pilot, who is in charge and who is commanding whom

That’s simple: The autopilot is flying and the pilot in command is monitoring. The PIC is responsible for the safety of the flight and acts accordingly including selection of the appropriate autopilot modes, monitoring the autopilot performance, and disconnecting the autopilot whenever it is doing something other than desired.

[hubcap]

19 hours ago, Pinecone said:

Many people do not notice tail wag.  I find those with tailwheel and/or glider time notice it more.

I used to a fly a lot with a friend in a Cherokee 180D he was in a partnership on.  One day we are flying along, and he started cussing under his breath.  I asked what was the matter.  He says, "Damn you, you fly my airplane 4 knots faster at the same power setting."  The difference was, I was using the rudders to stop the tail wag.

But again, you make my point.  Those without YD, see no reason for it.  I don't think I have seen a single post by someone who installed it and said, "that was a waste of money."

I can get an extra couple of knots if I use my foot like rudder trim on the pedals.

It may be that my rudder is a little bit out of trim. How difficult is it to adjust?