thomas1142 Posted May 5, 2018 Report Share Posted May 5, 2018 (edited) I have the opportunity to purchase a GDC 31 for my 1997 M20J to provide GPSS. I have Garmin 530W and a KFC 150 auto pilot. I have asked my avionics guy if all these components will work together and get the desired result, but he seems to be a bit busy at the time. So I am throwing this out to this group for some help. Edited May 5, 2018 by thomas1142 Quote Link to comment Share on other sites More sharing options...
donkaye Posted May 5, 2018 Report Share Posted May 5, 2018 1 hour ago, thomas1142 said: I have the opportunity to purchase a GDC 31 for my 1997 M20J to provide GPSS. I have Garmin 530W and a KFC 150 auto pilot. I have asked my avionics guy if all these components will work together and get the desired result, but he seems to be a bit busy at the time. So I am throwing this out to this group for some help. Yes, it will work very well. As Don said below, you won't believe what a difference it makes in flying the autopilot. I've had a number of students with that combination. 1 Quote Link to comment Share on other sites More sharing options...
DonMuncy Posted May 5, 2018 Report Share Posted May 5, 2018 So well, you will wonder why you didn't do it years ago. 1 Quote Link to comment Share on other sites More sharing options...
INA201 Posted May 6, 2018 Report Share Posted May 6, 2018 Based on other threads you’ll need an STC which is a little amu expense, not sure how much. Quote Link to comment Share on other sites More sharing options...
jetdriven Posted May 6, 2018 Report Share Posted May 6, 2018 according to DAC they want you to send the parts back and pay them 1200$ for a recert fee and stc. Rev. G of the install manual, however, still has the STC permission letter in it. Quote Link to comment Share on other sites More sharing options...
thomas1142 Posted May 6, 2018 Author Report Share Posted May 6, 2018 Not sure I understand this STC business. I buy the unit from a private party, let’s say for $800, then I have to get an STC for the company for another $1200 before I have to pay $xxx.xx to install it. Did o get that right? Quote Link to comment Share on other sites More sharing options...
gsxrpilot Posted May 6, 2018 Report Share Posted May 6, 2018 1 minute ago, thomas1142 said: Not sure I understand this STC business. I buy the unit from a private party, let’s say for $800, then I have to get an STC for the company for another $1200 before I have to pay $xxx.xx to install it. Did o get that right? Yes... technically... "following the letter of the law" You might have difficulty finding someone to do the install if you don't have a copy of the STC. If you can find Rev. G of the install manual, there is a copy of the STC in it. Quote Link to comment Share on other sites More sharing options...
donkaye Posted May 6, 2018 Report Share Posted May 6, 2018 14 minutes ago, gsxrpilot said: Yes... technically... "following the letter of the law" You might have difficulty finding someone to do the install if you don't have a copy of the STC. If you can find Rev. G of the install manual, there is a copy of the STC in it. If you have to do that, I'd just buy the unit new because between the STC purchase and the 3rd party purchase price you're paying nearly full price anyway and you'll have a warranty period. 2 Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted May 6, 2018 Report Share Posted May 6, 2018 On 5/4/2018 at 8:35 PM, thomas1142 said: I have the opportunity to purchase a GDC 31 for my 1997 M20J to provide GPSS. I have Garmin 530W and a KFC 150 auto pilot. I have asked my avionics guy if all these components will work together and get the desired result, but he seems to be a bit busy at the time. So I am throwing this out to this group for some help. Since it's more fun to spend someone else's money, by the time you add it all up, for not a lot more you could replace your HSI with a Garmin G5 and the GAD and I think you'd have GPSS and no mechanical HSI worries. Quote Link to comment Share on other sites More sharing options...
INA201 Posted May 6, 2018 Report Share Posted May 6, 2018 9 minutes ago, LANCECASPER said: Since it's more fun to spend someone else's money, by the time you add it all up, for not a lot more you could replace your HSI with a Garmin G5 and the GAD and I think you'd have GPSS and no mechanical HSI worries. I was going the same route and buy the Dac used and by the time it was over I now have a G5 HSI/GAD coupled to Century 2b. Works great! No regrets. Quote Link to comment Share on other sites More sharing options...
DonMuncy Posted May 6, 2018 Report Share Posted May 6, 2018 3 hours ago, thomas1142 said: Not sure I understand this STC business. I buy the unit from a private party, let’s say for $800, then I have to get an STC for the company for another $1200 before I have to pay $xxx.xx to install it. Did o get that right? Unfortunately, yes. It seems pretty rough that the company wants to charge one $1200, to reissue the STC in a new plane's name for a unit they already (presumably) made a profit from, on the first sale. I understand they went to a lot of effort to get the STC approval, and they want to maximize their income, but it would seem to me they would be better off in the long run, to only charge a reasonable fee for inspecting to make sure the unit meets the standards. Is that $1200 number reasonable? Hard to say, but it sure seems like a lot. 1 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted May 6, 2018 Report Share Posted May 6, 2018 You might try the field approval route. It won't cost you anything other than your IAs time to do the paperwork. Put together a package which includes the current install manual and what you want to do and send it to your IAs principal inspector. He will most likely approve it. 1 Quote Link to comment Share on other sites More sharing options...
thomas1142 Posted May 7, 2018 Author Report Share Posted May 7, 2018 Can you all explain “STC” to me. What requires an STC? If an avionics item is approved for your plane by the FAA, why is it necessary to pay for the factory approval paperwork. Hasn’t it been approved already? Seems like the proverbial circle jerk. Quote Link to comment Share on other sites More sharing options...
thomas1142 Posted May 7, 2018 Author Report Share Posted May 7, 2018 12 hours ago, donkaye said: If you have to do that, I'd just buy the unit new because between the STC purchase and the 3rd party purchase price you're paying nearly full price anyway and you'll have a warranty period. I have seen $1800 price for a new unit. Seems like new would be the way to go. Quote Link to comment Share on other sites More sharing options...
Bryan Posted May 7, 2018 Report Share Posted May 7, 2018 I received an email from DAC on this very topic just last week: We request that the unit be returned to DAC for bench check and any software update and the cost is $995 and includes STC authorization to reinstall the unit. This will not include annunciator or install kit, these can be purchased separately. -DAC Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 7, 2018 Report Share Posted May 7, 2018 Thomas, There are certain methods that the FAA uses to prove a device airworthy for use... The STC is a document that says a device has been tested and meets the expectations that it will provide the service you are paying for... When it comes to APs and their support devices like GPSS... the last thing you want is a random failure that takes out your AP while you are flying in IMC... Some devices are so specific, the testing is done over as wide of a range as possible... sometimes the range isn’t very wide and is limited by serial number... Or what it’s connected to... Some legal departments are so fearful of their own devices, they want to know that it is being re-sold properly to the the right end user... Think in terms of what could possibly go wrong... The GPSS stops working and you fly past your waypoint while heading towards terrain... The GPSS takes out your AP and you’re plane spirals towards the ground. More or less the reason STCs are around... they are the documented proof that the device is going to work for your plane. Getting the right version of a GPSS requires knowledge of what is on both ends... what gps and what AP is being bridged. Some GPS don’t have the outputs needed... Some APs are rate based and others are attitude based... Some companies want to sell you a first class ticket even when you are clear you have a CB budget. PP thoughts only... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
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