Smart Glide voice echo with G3X

[PT20J]

My Smart Glide seems to work fine, but there is an echo in the voice annunciations. A thread in BeechTalk caused me to investigate this further. It turns out that Garmin added Smart Glide to both the GTN Xi and the G3X. When enabled in the G3X, it allows Smart Glide to operate the GFC 500 using the G3X internal GPS so that no external navigator is required. This was likely done for experimental installations. When used in a certified installation, this is not approved and Smart Glide requires a GTN Xi. In this case, the G3X Smart Glide is not supposed to be enabled. Enabling it causes the echo. Someone on BeechTalk was kind enough to post an excerpt from the installation manual:

Smart Glide functionality on G3X STC installations requires a GTN 6xx/7xx Xi navigator running software v20.23 or later. All configuration for the Smart Glide function must be done via the GTN Xi in accordance with AML STC SA02019SE-D. The G3X configuration setting for Smart Glide must always be Disabled even when interfaced to a GTN Xi navigator.

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[RoundTwo]

1 hour ago, PT20J said:

My Smart Glide seems to work fine, but there is an echo in the voice annunciations. A thread in BeechTalk caused me to investigate this further. It turns out that Garmin added Smart Glide to both the GTN Xi and the G3X. When enabled in the G3X, it allows Smart Glide to operate the GFC 500 using the G3X internal GPS so that no external navigator is required. This was likely done for experimental installations. When used in a certified installation, this is not approved and Smart Glide requires a GTN Xi. In this case, the G3X Smart Glide is not supposed to be enabled. Enabling it causes the echo. Someone on BeechTalk was kind enough to post an excerpt from the installation manual:

Smart Glide functionality on G3X STC installations requires a GTN 6xx/7xx Xi navigator running software v20.23 or later. All configuration for the Smart Glide function must be done via the GTN Xi in accordance with AML STC SA02019SE-D. The G3X configuration setting for Smart Glide must always be Disabled even when interfaced to a GTN Xi navigator.

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Hopefully it’s just an echo and not an argument with different chosen destinations. I’m reminiscing about the red zone and white zone argument in Airplane.

[PT20J]

After some more research, I found that the echo was not caused by Smart Glide being enabled in the G3X. The GTN Xi installation manual calls for the GTN audio out to be connected to an unswitched input on the audio panel. However, the G3X installation manual calls for the GTN audio output to be disconnected from the audio panel. Having both connected was the cause of the echo.

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