We just installed a GFC500 in our 1977 Lance PA32R-300 with Dual G5’s and dual IFD540s. During the post-mod test flight the underspeed protection failed. Garmin is stating that the Avidyne IFD does not provide the inhibit signal required to engage the autopilot below the minimum airspeed set. (we tried 69 and 71 kts.) Of course they say the Garmin navigators provide AGL for min airspeed activation. I can’t believe Garmin received an STC for a product that fails underspeed protection when the STC does not state it is for Garmin navigators only. Anyone else have this config and experiencing the same issue? Thanks
