Garmin SOCATA TBM850, Pilot'S Manual

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190-00709-04 Rev. A
Garmin G1000 Pilot’s Guide for the Socata TBM 850 3
SYSTEM OVERVIEW
• GDC 74B – Processes data from the pitot/static system as well as the OAT probe. This unit provides pressure
altitude, airspeed, vertical speed and OAT information to the G1000 system, and it communicates with the on-
side GIA 63W, on-side GDU 1040A and on-side GRS 77, using an ARINC 429 digital interface (it also interfaces
directly with the OAT). The GDC 74B is designed to operate in Reduced Vertical Separation Minimum (RVSM)
airspace.
• GEA 71 – Receives and processes signals from the engine and airframe sensors. This unit communicates with
both GIA 63Ws using an RS-485 digital interface.
• GRS 77 – Provides aircraft attitude and heading information via ARINC 429 to both the on-side GDU 1040A
and the on-side GIA 63W. The GRS 77 contains advanced sensors (including accelerometers and rate sensors)
and interfaces with the on-side GMU 44 to obtain magnetic field information, with the GDC 74B to obtain air
data, and with both GIA 63Ws to obtain GPS information. AHRS modes of operation are discussed later in this
document.
• GMU 44 – Measures local magnetic field. Data is sent to the GRS 77 for processing to determine aircraft
magnetic heading. This unit receives power directly from the GRS 77 and communicates with the GRS 77,
using an RS-485 digital interface.