Garmin GI 275 Electronic Flight Instrument

Depending on version and configuration, the GI 275 replaces an attitude indicator, ADI, HSI, CDI, multi-function display, engine indication or, in the -50 version, an instantaneous vertical speed indicator. It can also serve as a standby ADI to a primary flight display.

Garmin describes it as a stand-alone drop-in replacement or as part of an integrated system. The installation and configuration decide which pages are available.

ADAHRS versions (-10, -20, -30, -40, -70) contain an air data computer and an attitude and heading reference, so the unit shows attitude, airspeed and altitude itself. The -20 and -40 versions add a third-party autopilot interface. The -30 and -40 versions are the Class III variants, and the -50 version adds the instantaneous vertical speed page.

The -60 and -70 versions are NVIS versions: -60 without and -70 with ADAHRS. Which version a given aircraft needs follows from its class, autopilot and lighting requirements.

For heading, the integrated ADAHRS uses a remote magnetometer, a GMU 11 or a GMU 44B (010-01708-00); the GI 275 powers the GMU 44B. The AHRS also needs either true airspeed or a GPS source for aiding, and Garmin recommends providing both.

A GPS source is required to calibrate the GMU 11 or GMU 44B. It can be an external navigator, or the optional backup GPS antenna for VFR use.

Garmin states that a single GI 275 can be the attitude source for the GFC 500 autopilot, and also shows mode annunciations and flight director indications. In a dual installation the second GI 275 can couple to the GFC 500 as well. The installation manual also lists the GFC 600 among the LRUs the GI 275 communicates with.

The -20 and -40 versions provide a third-party autopilot interface with heading and course error and gyro output.

The EIS covers single or twin reciprocating engines with 4, 6 or 7 cylinders. Per engine it needs a GEA 24 or GEA 24B, or a GEA 110 engine adapter, with CHT and EGT, RPM, oil temperature and oil pressure sensors, plus a manifold pressure sensor where the aircraft requires one.

The GEA adapters and engine sensors are not part of the GI 275.

A panel modification guide, 115-03278-00, is included with each unit. The connector kit is a separate required accessory: 011-04809-00 for the Base, 011-04809-01 for the other versions. The installer fabricates the cables and, on ADAHRS versions, the pitot and static hoses.

Backup battery, magnetometer, backup GPS antenna, GSB 15 USB charger and engine adapters are separate P/Ns in Garmin's accessory list.

Garmin announced EASA approval for installation in over 1,000 single- and multi-engine aircraft models in January 2021. The installation manual adds that TSO articles still need a separate approval for installation in an aircraft.

A certified aircraft therefore needs an approved modification that covers its type and a Certificate of Release to Service. AIR TEAM confirms the approval path for the type before a firm installation quote.

Fit depends on the P/N, the aircraft type and the instruments to be replaced. A repair of an existing unit, listed under 011-04489-00 (Garmin's unit-only P/N of the Base), also needs the serial number.

AIR TEAM confirms whether a unit-only P/N ships with a battery; a repair quote confirms the scope of the repair.