Will the digital DG (GPS based) on the ADI meet the requirements of ?91.205(d)(9) for a gyroscopic direction indicator in an experimental aircraft?
 
Will the digital DG (GPS based) on the ADI meet the requirements of ?91.205(d)(9) for a gyroscopic direction indicator in an experimental aircraft?
I would doubt it since the ADI is not a gyroscopic direction indicator but a GPS derived ground track indicator. The turn rate is gyroscopic but the direction indicator is not. Perfectly usable to get you on the ground as a backup but does not meet the requirement IMHO.
 
Kinda bass-ackward logic though. I mean, I'm sure the regs were conceived long before readily available gps technology, and unlike a gps DG, a gyro DG simply tells you which way you're pointing, not which wy you're going.