Peter wrote:
Indeed it should, but it does not
Again, the autopilot is (we assume in this thread) NOT STCed, NOT APPROVED FOR A KING KATMAI. It is approved for a Cessna 182Q. The decision to apply that STC meant for a Cessna 182Q to a King Katmai (that is, a Cessna 182Q with another engine, added canards, etc) IS A DECISION OF THE INSTALLER. You cannot blame the person that obtained an STC for A STANDARD CESSNA 182Q not to list settings for a King Katmai.
If the Katmai version is not listed on the STC applicability list, in that case the installer should have known that the 3100 autopilot cannot possibly work properly on the Katmai version, so should not have installed it. It would be daft to think the autopilot will work correctly on a plane with such different control loop behaviour.
I am not familiar with English grammar formally. Not my first language; never studied it.
Peter, It’s not semantics or grammar – it is the very logic of STCs.
"S"TC is the abbreviation of “Supplemental Type Certificate”. Therefore you take an airplane with an existing type certificate (TC) and add a modification that has an STC for that type. Without an underlying TC there is no STC and the STC always refers to one (or several) TCs.
In this case, the “King Katmai” is technically not an airplane of its own with a TC, but a modification of an 182Q under the Peterson STC. As it is still a 182Q, its TC is the original 182(Q) TC.
Therefore by the nature of the STC concept, there can not be such a thing as an “STC for the 3100 installation in a King Katmai” as there is no such thing a s a “King Katmai TC”. The STC for the 3100 is – amongst others – supplemental to the 182(Q) TC.
Technically the OP has a 182(Q) and wants to install two different modifications based on two different STCs. It is his (and the installers) responsibility to make sure that those two modifications have no unwanted interactions. Both manufacturers of the modifications do only have to ensure that their mod works on the unchangenged 182(Q) individually.
Malibuflyer wrote:
Therefore by the nature of the STC concept, there can not be such a thing as an “STC for the 3100 installation in a King Katmai” as there is no such thing a s a “King Katmai TC”. The STC for the 3100 is – amongst others – supplemental to the 182(Q) TC.
Not quite. One can ask for a STC for an TC modified per another STC. See e.g. http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/672a0d4cf322cb13862581e70054c5c4/$FILE/SA03976NY.pdf. local copy
That is STC number SA03976NY to TC 3A21, but is only applicable to TC 3A21 modified per STC SA1003NE.
Malibuflyer wrote:
Technically the OP has a 182(Q) and wants to install two different modifications based on two different STCs. It is his (and the installers) responsibility to make sure that those two modifications have no unwanted interactions.
That is correct. But the AP STC holder could ask for a supplementary STC for their AP for “Cessna 182Q as modified by STC XXXX” where XXXX is the reference of the Peterson “King Katmai” STC, with the corresponding technical data (and in particular adapted settings for envelope protection). This would be helpful for the OP and his installer. Whether there is a business case for the AP STC holder to do so is another issue; maybe Peterson can convince them to do it, since (according to their website) they currently mount an older/predecessor model of that AP on the aircraft they sell/modify.
Why don’t we relish in the unexpected freedom to make one’s own assessment on whether to apply two STCs to the same airframe or not?
Do we really want an additional rule requiring a third STC if two STCs are applied to the same aircraft?
Normally I would agree with you but the problem is that some avionics installers don’t have the competence to make that judgement, and this is an example of that.
The only correct “judgement” in this case would have been to not install that autopilot at all.
I am now talking just like that outfit in Cologne 
This issue must also be a risk for things like turboprop conversions, where due to getting the power maintained to a higher altitude you are getting a much higher TAS, which increases the autopilot loop gain. It would not surprise me if some autopilots STCd for a PA46 get unstable at the upper corner, especially in certain loading conditions.
Cobalt wrote:
Do we really want an additional rule requiring a third STC if two STCs are applied to the same aircraft?
No. We definitely want the installer to be legally allowed to make that judgement. But, STC holders can/should also apply for the “third STC” when it makes sense. Like a prop for an engine that is not the one on the TC. Or possibly maybe the case of an autopilot with envelope protection for an STC that changes the handling characteristics, and especially the stall speed.
The only area of contention here is the stall speed difference between the standard C182Q and the King Katmai as set in the envelope protection, every other parameter has no affect on upgrading from the 55X to the 3100 (I think).
It has now come to light that the envelope protection is indeed disabled from active interference when the disable button is pressed and if the aircraft goes outside the envelope the autopilot gives an audible warning and a flag warning on the G500. The only time the autopilot intervenes if going outside the envelope is if it is on and enabled.
We have this information from the field service engineer in the US. Why we were told the autopilot will intervene even when disabled I really don’t know.
This whole thing is because the 3100 is so new and only just released on the market. I had been told it had been out around a year – hmmm. It wasn’t perhaps my best decision to upgrade so early. I should have waited a year or so to allow the 3100 to mature. The installer is finding many issues with wiring diagrams and even connectivity with the set up procedures so what should have taken a week is going to take a month.
One thing is for sure, I’m going to test the envelope protection out for myself before attempting a STOL landing. Rotate speed first time will also be as for the 182 Q first take off.
With autopilots, it is important to understand exactly how much “off” it is for a given “off” switch, or if it merely “disengages” it.
As I dimly recall, the disconnect switch on the yoke should not only send a “disengage” command to the autopilot, but also remove all power from the servos while held down, but this may also be installation specific. In the Columbia pre G1000, the big autopilot switch did that, too. After G1000, there was only the circuit breaker, IIRC.
Envelope protection is supposed to work even if the autopilot itself is “disengaged”, i.e., when you hand fly.
the disconnect switch on the yoke should not only send a “disengage” command to the autopilot, but also remove all power from the servos while held down
Exactly correct for the King boxes. The red button switch interrupts the power to the servo solenoid-operated clutches.
Obviously, for EP the servo power must be maintained even though the red button is pressed. This introduces a big risk… if the software crashes, you cannot overpower the autopilot unless the slipping clutches work correctly. On many installations they are stuck (corrosion, debris, misadjustment) and the owners don’t know because they never do the preflight “overpower” test.
There must be a Master switch, or maybe just a circuit breaker, and you better know where this is in case you have to pull it in a hurry 
Someone told me the EP disable is in the G1000 menus and one hopes this is not the only place…
You cannot overpower the servos, because the gearing is something like 1000:1. There is just the slipping clutch.
