Gallois
The blockage is the potential market and the fact that having never been certified in the USA Garmin will find themselves dealing with a foreign certification authority. Garmin do all their autopilot certification in-house and as there are no DR400’s in the USA this is a further problem.
Secondary problems are there are few people who understand wooden aircraft construction and how to install such systems in wooden aircraft.
As a company we would be happy to help Garmin our expertise is in major repair of wooden and composite aircraft and have a staff member who has been involved with autopilot integration of military aircraft as well as having a number of Avionic certification staff.
Some Robin aircraft have been fitted with autopilot’s but the Robin trim system is quite unconventional ( by industry standards ) so pitch trim would be a hurdle to overcome……… but not a game stopper.
My own feeling is it would take a number of people who are prepared to put up money and order autopilot systems for Robin aircraft to get Garmin interested in such a project. I can understand why people would be uneasy about putting money up front as we see so many vapourware products, however Garmin is a big company with a reputation to uphold and unlikely to fail in such a project.
I really appreciate your response but I don’t understand why Garmin won’t sell one of their autopilot to you as a Garmin dealer to fit into any of the wooden Robin’s.
Robin themselves fit Garmin G500 GTN650 and GTN 750 to their aircraft so why not the autopilot.It’s not as if they don’t install autopilots in their aircraft.
As most wooden Robin’s are very similar in their structural build much of the installation will be similar to any other. Although I accept that each is individual as it is handmade.
So I don’t understand why pressure has to be put on Garmin in order for a company like yours to be able to do what you are good at (which incidentally Garmin do not do and have no expertise in such).
After all if you manufacture a product, surely you want to sell it otherwise what’s the point.
Incidentally Robin have changed their trim system on the DR401 it’s now on the stick.They have also added pitot heat.
What seems to me to be so senseless is that I could buy all the above kit (if Garmin would sell it to me) and install it in a homebuilt D140 document the ground and flight tests’’’, have it checked and added to my Cof A by OSAC (basically an admin job).
Admittedly I couldn’t fly IFR but that is a regulatory thing where we know who and how to pressurise to get that changed if one could garner the support.
A small company like Nogaro were able to fit Rotax engines to Robin’s with IIUC only one club client. And also IIUC the regulatory hurdles such as the STC were neither massively costly nor massively time delayed. I would argue that changing an engine is far more structural than any avionics installation.
Am I too dumb to see the problem?
An autopilot STC needs flight testing, and quite a lot of it. An autopilot forms a part of a control loop with the aircraft aerodynamic behaviour.
This is not like an engine which has a weight of x and output power of y, dimensions z, and by choosing a prop which can absord the power that’s more or less the end of it.
Peter wrote:
An autopilot STC needs flight testing, and quite a lot of it. An autopilot forms a part of a control loop with the aircraft aerodynamic behaviour.This is not like an engine which has a weight of x and output power of y, dimensions z, and by choosing a prop which can absord the power that’s more or less the end of it.
Peter, while I understand the legal side of it, why is it that GFC500 on certified requires an STC and nothing on experimentals?
It is the same servos and G3X / G5, just no piece of paper for the non-certified world…
This is a Robin thread, but an STC is not applicable to homebuilts because they don’t have a Type Certificate. “STC” = Supplemental Type Certificate.
Although there are some Annex 1 (but factory built) Robins; I flew in one a couple of years ago.
Choosing the control loop parameters conservatively can yield a “working” system…
Surely an autopilot needs testing to demonstrate it works in all set ups.
There are several homebuilts and ULMs with perfectly good autopilots. Both 2 axis and 3 axis and coupled to both Dynon and Garmin navigation and display systems.
Here the pilot/owner/builder does the flight testing, produces as a dossier which is passed to OSAC who add this into your air worthiness documents. No STC involved.
I’m not questioning the requirement for an STC in certified aircrft or for flight testing. Full testing by an avionics installation company or person is a must to keep the customer pilot safe.
And yes there are costs involved. But why should a Garmin product which has a TSO rely on Garmin to test and approve or whatever, individual aircraft. They do not have the installation expertise.
An STC is surely for a type and I can understand a group of that type of aircraft getting together to do one set of installation plans and testing for a type of aircraft. I would argue that one STC could cover all wooden Robin’s. Although there are differences they are mostly slight.
The Robin trim A and C referred to has already been installed and flight tested in a wooden Robin. So it might be that this would also have to be retrofitted by the avionics installation company. And an STC produced.
My other point would be that an STC for an individual aircraft can be produced in terms of admin with EASA for AIUI around €120.
It may be a little more for a whole type. Admin does not mean extra safety it just means that something is documented as having been tested and shown to do what it is supposed to do.
All of this happens in the ULM and homebuilt world without STC but with a dossier showing performance and limitations from testing. Now having flown with autopilots on ULMs, homebuilts, and certified aircraft I have found very little difference in their performance.
So why would Garmin or how can Garmin stop owners having the equipment they want in their own aircraft? To me it is not logical and certified aviation seems to be the only world where these sort of barriers occur.
There is far more to autopilot certification than meets the eye with stability across the speed range, and damping of disturbance’s to the aircraft being just two of the issues to be looked at during flight testing.
I think your estimate of the costs are a little wide of the mark, I would not expect to start such a project without a budget of less than €25K for EASA STC paperwork. On top of this would be the cost of fitting the kit, and flight testing and the adjustments to the system to sort out the problems that arise during flight tests.
All this is not a trivial undertaking as the installation has to meet international standards, this is why Garmin ( or any other company ) won’t sell you and autopilot system for a certified aircraft until the aircraft meets the required standards. To do otherwise would invite the interest of ambulance chasing lawyers as soon as an aircraft fitted with such kit had an accident.
A_and_C wrote:
There is far more to autopilot certification than meets the eye with stability across the speed range, and damping of disturbance’s to the aircraft being just two of the issues to be looked at during flight testing.
A_and_C, sorry, but in what way the GFC500 hardware and software for experimentals is different from the GFC500 for the certified world?
Genuine question, no trolling! What surprises me a lot is the that it is the same set of components, and for the experimentals you could install them anywhere, and for exprimentals nowhere, unless there is an STC.
It’s the last paragraph don’t get.
I totally understand cost of equipment..Paid to the chosen installer Garmin approved who buys direct from Garmin. Hopefully with some sort of instructions or diagram.
I also understand cost of installation and cost of a testing programme following installation and producing an operating manual.
All this I get and you would do the same on an experimental or a ULM.
A copy of the dossier then has to be lodged with the regulator.
The aircraft manufacturer in the case of a certified aircraft would also need to agree that the installation, dossier etc can be added to their type certificate.
IIUC the original Nogaro/club STC for the Rotax conversion was nearer the €120 than the €25k. Robin obviously agreed that conversion as they allowed the supplement to be added to their type certificate.
My question with the Robin is that they already have the Stec55x installed on Robin 401 and Robin 180 Regents. So we know they don’t object.in principal to autopilots. Their interest would be how any different autopilot would merge into their aircraft and not threaten safety. So what they would be interested in is studying the flight tests and the attachments to the aircraft.
Garmin would already be covered as the A/P I assume is TSO’d and they should trust the installer to do the job well as they are an approved dealer.
But that’s just my logic. Can homebuilders buy any of the Garmin autopilots for self installation.
The answer is likely to be in somebody “sponsoring” the STC i.e. putting in some money in the hope that enough owners who expressed interest will buy it.
The amount of “hope” varies according to the typical mission profile of the fleet in question. See the many previous threads. If you are talking about a fleet of say 2000 TB20s (let’s assume the TB20 had no decent avionics options) then you have a solid demand for avionics. If the fleet is say 2000 Robins, most of which are in the French aeroclub community, then there will be far fewer people with a properly developed cheque book withdrawing-from-pocket reflex 
Sponsorship of STCs is a very tricky business – see e.g. here. And lots of avionics shops have got their fingers burnt on Robins, because when it comes to paying out tens of k on a plane used on nice VFR days there is a lot of talk the talk and much less walk the walk.
For a homebuilt, it’s not that difficult to adjust the loop parameters in flight, especially if you are interested only in cruise operation. If you start with zero derivative term and a low proportional gain, it will be stable. May not work great but won’t do anything wild. The integral term removes steady state errors so not that important. So you start by tweaking the gain up until it starts to porpoise and then back off a bit. Do this at fast cruise and minimal weight where the open loop gain is the highest i.e. the most critical setting. I’ve done this stuff hundreds of times when designing electronic products.
Can homebuilders buy any of the Garmin autopilots for self installation.
According to posts on US social media, where Garmin have factory presence (they studiously avoid interacting in Europe), Garmin will sell you stuff like a GTN750 (I don’t know about autopilots) if you prove it is a homebuilt. They want to see the evidence. That way you are not forced to buy via a dealer (which you are, for a certified sale, in most cases). I think the non-cert G5 is freely sold…
But also you can obtain anything, either secondhand (loads of used box dealers out there) with no questions asked, or brand new via a friendly dealer. That should do for a one-off or a small-qty requirement.
