The EFIS-D10A/EFIS-D100's attitude algorithm is normally aided by pitot-based airspeed information. If the EFISís airspeed source gets blocked, the EFIS will automatically use GPS ground speed to continue to display accurate attitude. The GPS antenna must be connected in an EAA STC installation.
Note: In order to not reduce the signal, the SV-GPS-251 module must not be painted
No, the HS34 will allow interface to a panel mounted nav/gps for HSI information. This is only approved for experimental aircraft.