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GI 275 Software Update 2.32 and STec 20 Heading Scaler adjustment

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The new GI 275 Software Update 2.32 for autopilot operation (for me an analog STec 20 that uses heading mode for emulation) works much better than the original "Mickey Mouse" procedure with the GPSS hidden three levels down. Sometimes you wonder if Garmin actually has its products tested in flight by pilots. Its still not ideal however, and I will probably go with the now allowable "discrete switch".

The issue for me is alternating between flying an assigned heading and GPSS, such as you might do when being vectored in the terminal area, changing to GPSS, and then being given heading vectors again after a missed approach. Of course when flying single pilot IFR in the clouds and turbulence. Sounds simple but it was a lot of work for me to do all the three level button pushing while bouncing around in the soup.

The new procedure is shown on the first pic--the GPSS switch from Heading or back to Heading mode from GPSS requires one long push on the inner knob to bring up the first level menu and then a twist on the outer knob to go to the AP REF or HDG Bug button where one push on inner knob takes you to GPSS on your autopilot (assuming its set for HDG mode). One screen touch on the "Back" button top left takes you back to the panel. Going back to heading mode works the same. The second pic shows the panel after the switch with GPSS active and in straight and level flight. I access this menu on my #2 ADAHRS GI 275 while in HSI mode as my hand fits more conveniently at this level and doesn't block anything else in the process.

Last pic shows the whole panel. If you look closely at the flight track on the IPad you can see a bit of meandering as I went from heading to GPSS. The issue was that the autopilot had gone back to ready mode from heading (see pic 2). Don't know what I did to cause this but I need to remember to scan the autopilot mode to make sure that heading mode is still engaged. It may be that when switching from heading mode to GPSS its necessary to tell the autopilot again that you want heading mode.

Second subject was getting my STec 20 adjusted to crisply fly a GPSS approach. Turns out the GI 275 has an internal "heading scaler" adjustment for different autopilots. Default is a 1.0 value which was not giving me standard rate turns, but big loopy turns that used up more sky than was desirable (or allowable) such as for a procedure turn course reversal. We went first to a 1.1 value because my avionics tech didn't know what would happen. That showed a change so we tried 1.2 and then jumped to 1.5 where it now gives me standard rate turns crisp enough to do a nice procedure turn course reversal. I think the adjustment value goes up to 9.0 so there is a lot. I will stay with 1.5 for now.

BTW, there is a lot more GI 275 discussion on the Beech and Mooney forums so it looks like the units may be more popular there.

GI 275 Software Update June 2021.jpg
GI 275 Software Update2 June 2021.jpg
GI 275 Software Update3 June 2021.jpg
 

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