Cris

Not that it helps but the same thing happened to the early adapters the first time around. A friend of mine ordered a lynx 3 weeks before the rebate program was announced. As I recall Lynx gave him some sort of upgrade at no cost to partially make up for the $500. I think other mfg’s did similarly.

Great info. Do you happen to know from where these might be ordered or replaced?

Cable adjustment of the roll servo is my best guess. Go to the Stec dealer for correct adjustment. Flying to the left of the line is a simple adjustment on the panal controller.

If you Google you will find the Stec ST 901 Manual. This is the info page for the T approach you described. From your description it seems that the issue you are experiencing is that the S-Tec is not intercepting the various segments in a timely manner. I think you believe that it needs to have a greater bank angle to resolve the issue. However typically the IAF’s are not fly over points. Therefore the unit should calculate and turn prior to reaching the IAF so that it smoothly ends on the next segment. If this is not occurring and you are using the unit in accordance with the manual I’d suspect it needs adjustment. Best course of action is to take it to an Stec dealer who regularly works on this autopilot. It could be a simple cable adjustment or reracking the control head etc. The servo might also be drawing high starting voltage which would slow its startup and cause it to fly thru the course. These autopilots are relatively bullet proof so should not be that costly to diagnose and repair. 3-6 5th Ed. Feb 15, 08 S–TEC Fig. 3-2. GPS-T Approach 1. a. Set the Heading Bug under the Lubber Line. b. Engage the GPSS Converter's HDG mode. c. Engage the autopilot's HDG mode. d. Program the GPS Navigator with the desired approach. e. Engage the GPSS Converter's GPSS mode. f. The autopilot begins tracking to the Initial Approach Fix (IAF). 2. a. The autopilot intercepts the IAF, then makes a 90° turn, and begins tracking to the Final Approach Fix (FAF). 3. a. The autopilot becomes established on the inbound course. b. At the Missed Approach Point (MAP), disconnect the autopilot for a landing or go-around, as required.

This autopilot is limited to 90% of standard rate. There is no pilot adjustment so it will need to go to the dealer if you are not satisfied with the turn rate. However before you do so try to see how it works in different scenarios. As an example use the left/right roll command to determine if it is giving the same rate indication as approaching a course for GPS/VOR/LOC. Use the high setting for GPS/LOC. I think Heading on the St50 and GPSS on the Aspen might also work. Remember it will use a more shallow bank angle depending on what it needs to intercept. Basically it will not intercept unless you have it within 10% of the course before you select the mode except when I GPSS mode. Finally standard rate depends on your airspeed. Check the accuracy of your Turn Coordinator by: Take the first two digits of your airspeed (or just the first digit if you are under 100kts) and add 5 to it. That is your bank angle to get a std rate turn.120 kts, add 12+5=17 degrees of bank gives you a standard rate turn. Stec will only go to 90% or 15 degrees in this example. Don’t confuse your attitude Indicator at 15 degrees in this example with the assumption it is the standard rate shown on the Turn Coordinator. 90 kts, add 9+5=14 degrees of bank gives you a standard rate turn. Compare that to the Turn Coordinator. Last but not least you can stay on the magenta line if you set your GPS to one mile instead of the standard 3 mile enroute so it wont get to far off course before adjusting.

Since you intend to upgrade from an initial GPS, installation costs to install twice will be substantial. So use some of that extra money to go with a 430 (w) or maybe a 400 (gps only which is really cheap) Latter you can upgrade to the Avidyne 440 without any additional install costs. If you sell the aircraft it offers an inexpensive upgrade path for a new owner.

All Garmin firmware updates require a trip to the dealer. Some charge some don’t

Yes V 6.50 includes the query keyboard for the GTN 650

As Marauder points out a lot depends on the math. Clearly if you have an Stec autopilot the upgrade path is quite competitive for a similar system ie Garmin. I don’t look at Trio/Trutrack as having similar capabilities. What needs to be considered is that the Garmin GFC500 requires 1-2 G5’s which adds to the cost. However if you have G5’s you don’t look at it from that perspective. There also is a higher install cost with the Garmin as the existing servo’s need to be removed and new ones installed. How much will the shop charge for that? Would 25 hours more or less be a good guess? Stec is like the Swiss Army knife of autopilots and will interface with all your existing equipment including steam gauges and EFIS. If you have steam gauges they provide an Air Data Computer as part of the kit at no additional charge according to Jack Somsen of Genysis which is huge. So the Stec install includes all of the bits and pieces at one stated upgrade cost based on the specific aircraft in which it will be installed. In my case I like what I have so this works well for me and is probably less expensive than what the GFC500 will ultimately cost. For others the numbers and equipment might be different.

Yes I think it probably went to anyone that has expressed interest. Presumably the servo’s will be certified as part of the installation. With a two year warranty on something that has proven itself I’m ok with that. The “other guys” only offer a 1-2 year warranty on their “new”. For me it’s a non issue but I do understand the point.

Found this from Jack Somsen on Beechtalk. Looks like the ADC is included at no extra cost. This might push me to upgrade for sure. “The 3100 takes some of that info from steam gauges and some from an ADC. If you don't have an ADC, we provide one as part of the kit (no additional cost). If you have an EFIS, we use that as the main source. In your case, it looks like we would use info from the Garmin GPS and the ADC we provide. You would retain your S-TEC servos and replace the 55X control head with the 3100 (in simple terms). Shoot me an email at jack.somsen@genesys-aerosystems.com and I can provide contact info for the dealers in Australia. We have a few options for you. We have started the STC for the 310/320/340 airframes and you still have time to get in on the extended warranty. And that includes 2 years on your existing S-TEC servos...”

A resistor which is only available as an s-tec dealer needs to be installed in the control head to tell it that a GPSS is now part of the system. At least that is how mine needed to be modified in addition to the integration resistor- S-tec 30

Curious as to whether or not you are having it installed by an S-Tec shop? I recently had one installed and it would not work correctly. The Avionics shop that did the install wired it incorrectly and the resistors were not changed for my equipment. Took it to the S-Tec dealer and now it works flawlessly.