This has been discussed I believe but I can't find the thread. Any updates on the approval of the Garmin GFC 500 for Robertson Stol equipped wagons? At least a few have been done stateside and one in Canada through probably FA but do not want to deal with that. I can't stomach the idea of paying $20K for a new(but old) s-tec. Also, If anyone is upgrading from an s-tec 30,55, etc that is STCd for a 12V 185 and wants to get rid of theirs I am interested.

Can you not take the well worn route that the mechanic signing off the installation has verified that the two STCs are “compatible”? This is a routine assumption (and requirement) on ALL STC installations.

And, why would they not be?

MTV

mtv wrote:Can you not take the well worn route that the mechanic signing off the installation has verified that the two STCs are “compatible”? This is a routine assumption (and requirement) on ALL STC installations.

And, why would they not be?

MTV

Probably because it is more than paperwork. It is my understanding that the normal outboard attachment point is the belcrank modified by the RSTOL kit. For s-tec, you must have a simple bracket that they make(but do not have on the shelf) or that Robertson made. Cessna autopilot had some sort of solution too. So if the plane never had an autopilot, the challenge is more than just the autopilot settings which should not be any different in flap retracted configuration anyway.

frstnflt wrote:

mtv wrote:Can you not take the well worn route that the mechanic signing off the installation has verified that the two STCs are “compatible”? This is a routine assumption (and requirement) on ALL STC installations.

And, why would they not be?

MTV

Probably because it is more than paperwork. It is my understanding that the normal outboard attachment point is the belcrank modified by the RSTOL kit. For s-tec, you must have a simple bracket that they make(but do not have on the shelf) or that Robertson made. Cessna autopilot had some sort of solution too. So if the plane never had an autopilot, the challenge is more than just the autopilot settings which should not be any different in flap retracted configuration anyway.

Ah, so! Thanks for clarification. I’d start looking in salvage yards, and trying to find drawings for parts…. Good luck.

MTV

frstnflt wrote:

mtv wrote:Can you not take the well worn route that the mechanic signing off the installation has verified that the two STCs are “compatible”? This is a routine assumption (and requirement) on ALL STC installations.

And, why would they not be?

MTV

Probably because it is more than paperwork. It is my understanding that the normal outboard attachment point is the belcrank modified by the RSTOL kit. For s-tec, you must have a simple bracket that they make(but do not have on the shelf) or that Robertson made. Cessna autopilot had some sort of solution too. So if the plane never had an autopilot, the challenge is more than just the autopilot settings which should not be any different in flap retracted configuration anyway.

I have a stec and Robertson, didn’t know about that, interesting.

I have the s-tec 50 in mine. I called Garmin last year to ask about their autopilot and they didn't have much interest in finding a solution for such a small market which I can't blame them for. I even suggested a Placard stating flaps couldn't be deployed but their general answer remained the same. I couldn't get any specifics out of them about the why and how but maybe it should be revisited. I know a guy who decided to take his Robertson out to get the GFC 500 but I'm not willing to do that.

Here’s the response from Garmin. What is benefit of NTO?


Hi Andrew,



“Garmin Engineering is still looking for an aircraft to bring in to perform the certification STC for the C180/185 w/ a Robertson STOL kit installed. We may have located a candidate, but if that is something that may interest you, please let me know. Any program is at a minimum 5-6 months away before being completed.

In the interim, there have been several aircraft modified with the GFC 500 on filed approvals, for which Garmin Engineering can supply an NTO (no technical objection) for the changes required to the aileron bellcrank installation.”

It means they accept no liability should you proceed

frstnflt wrote:Here’s the response from Garmin. What is benefit of NTO?


Hi Andrew,



“Garmin Engineering is still looking for an aircraft to bring in to perform the certification STC for the C180/185 w/ a Robertson STOL kit installed. We may have located a candidate, but if that is something that may interest you, please let me know. Any program is at a minimum 5-6 months away before being completed.

In the interim, there have been several aircraft modified with the GFC 500 on filed approvals, for which Garmin Engineering can supply an NTO (no technical objection) for the changes required to the aileron bellcrank installation.”

thanks for the update!

It's different because the aileron bell crank is entirely different. I'd roll the dice that if you found the bell crank out of a 185 with a R STOL and an S-tec, you may be able to poach some of the engineering from S-tec. I'll try to find the drawings from my S-tec install. It has some info on the marriage of the 2.

Aeropod - This is a great opportunity for you to come up with another STC!! I have a Robertson on my 180 and would like to go with an autopilot some day.

RC5280 wrote:Aeropod - This is a great opportunity for you to come up with another STC!! I have a Robertson on my 180 and would like to go with an autopilot some day.

STCs on someone else’s STC is a cumbersome pain in the ass, I might skip that

Yeah, plus you would sell what? 2 of them?

Anyone actually done the Gfc in a RSTOL 185 I’m ready to pull the trigger but would like to know what others have done to interface the servo with the bell crank?

electricsnail wrote:Anyone actually done the Gfc in a RSTOL 185 I’m ready to pull the trigger but would like to know what others have done to interface the servo with the bell crank?

I'm aware of 2. One already had s-tec 55 so attached the bridle cable to existing s-tec bracket. The other was in Canada. He found the drawings of the s-tec bracket, fabricated 2, sent one for testing approved by transport Canada, and used the other. If you already have cessna autopilot, s-tec, or century its much easier. So you need an installer willing to take on a small engineering challenge and potentially large and expensive legal challenge with no guarantee.

Saw this today...wonder how close the 206 is to the 180/185?

Garmin's autopilot approved for more GA aircraft
The Federal Aviation Administration has granted supplemental type certification for the Garmin GFC 500 autopilot to be used in certain Robertson STOL-equipped Cessna 206 aircraft and Piper Twin Comanche PA-30B, PA-30C and PA-39 models. The autopilot is now approved for retrofit in 26 lines of general aviation aircraft models, and properly equipped airplanes can also utilize Smart Glide, which offers emergency landing guidance. Full Story:https://www.avweb.com/aviation-news/garmin-adds-two-new-piston-aircraft-lines-to-its-gfc-500-market-list/

I just spoke with a tech at Garmin. They have a Robertson equipped 185 and are estimating GFC 500 autopilot STC approval by "second quarter 2023, depending on FAA". He said their currently approved Cessna 206 RSTOL STC is the same engineering as a 185 RSTOL, but it will still take 6 months work dealing with the FAA....but it will happen.

Thats great. I love my GFC500 in my 185. Putting the YD in soon.

Garmin has been telling me 6 months for a few years now for a full STC with installation kit for the rstol 180/185. It is doubtful it will happen. At least now they have have a no technical objection letter to installation with a bracket which is a bit of a gray area, but obviates the need for field approval if your installer is comfortable with it. If you already had an STEC you can use the bracket from their installation kit. An approved STEC dealer can buy the bracket from Genesys, but then you would need the STC for an stec autopilot too. Fortunately, now Sierra Industries, the holder of Robertson STOL was able to produce the bracket that they used to make. It should fall as an option of the rstol kit under the umbrella of the rstol STC. Hoping for install next month!

I now have the GFC 500 in my RSTOL 180 and it is awesome. It is placarded for No Flaps but I am loving it. I did have the STEC 50 in it.