Garmin 300XL -Hold- HSI Course

[sgfreeman]

I have a D-180 (master), D-100, HS-34, AP-74, SL-30, GTX-327. Everything works great except when I put the 300 in the "hold" mode through the innunciator button to go into a holding pattern or missed approach, I have no ability to adjust the HSI course value with the HS-34(when the holding pattern is off a GPS waypoint or IF). Also, when the Autopilot is slaved to the GPS, the course knob on the HS-34 is inactive. Anyone had this issue and been able to solve it? Any help would be appreciated.

 

[dynonsupport]

The latter part of your question - the course knob being inoperative during normal GPS course operations, is by design. The GPS isn't designed to take external course adjustment input in that mode. In the virtual VOR / OBS mode, the 430 series will listen to an external course adjustment to allow the inbound course to be adjusted, kind of like a VOR. But I'm not sure whether the 300XL supports this function. We do send course back on the ARINC transmit wires, so to make sure that those wires are connected to ARINC recieve lines on the 300XL, and that any appropriate ARINC settings are set so that it's expecting to receive course information.