190-02246-11
GI 275 Part 23 AML STC Maintenance Manual
Rev. 1
Page 2-8
2.4 LRU Description, Control, and Operation
2.4.1 GI 275 Display
The GI 275 is a multi-function electronic instrument display. The GI 275 can be configured as a Primary
ADI, HSI, MFD/Standby ADI, HSI/Standby ADI, MFD, or EIS display. The GI 275 ADAHRS and
AP variants include an integrated ADAHRS.
Figure 2-3 GI 275 Display
2.4.2 VFR GPS Antenna
The GI 275 has an internal VFR GPS that may be used as a primary GPS source for VFR navigation only
or as a backup GPS. The internal VFR GPS is not approved as an IFR navigation source. If the VFR GPS
antenna is installed, the internal VFR GPS is automatically used when the primary GPS source is
unavailable. The GI 275 internal GPS antenna is installed on the instrument panel glareshield. Only one
antenna is required for all installed GI 275s in the system. GPS data will be forwarded from the GI 275
directly interfaced to the GPS antenna.
Figure 2-4 VFR GPS Antenna
2.4.3 Integrated ADAHRS
The GI 275 ADAHRS and AP variants have an integrated ADAHRS that provides altitude,
vertical speed, airspeed, attitude, OAT, and heading data for flight instrumentation. The internal ADAHRS
receives data from the GMU 11/44B, GTP 59, and pitot-static system. The integrated ADAHRS utilizes
GPS signals sent from the internal VFR GPS or an external GPS/SBAS source. Attitude, heading, and air
data can be sent to external LRUs via ARINC 429.
