Garmin G2000 Pilots Guide - Page 51

SYSTTEEMM OVERVIIEEWW FLIGHT INSTRUMMEENTS EEIIS AAUUDD&IIOOCNP&ASCNNESL System Overview GPS Input Failure Note: In-flight initialization of AHRS, when operating without any valid source of GPS data and at true air speed values greater than approximately 200 knots, is not guaranteed. Under these rare conditions, it is possible for in-flight AHRS initialization to take an indefinite amount of time which would result in an extended period of time where valid AHRS outputs are unavailable. Two GPS inputs are provided to the AHRS. If GPS information from one of the inputs fails, the AHRS uses the operating GPS input and an alert message is issued to inform the flight crew. If both GPS inputs fail, the AHRS can continue to provide attitude and heading information to the PFD as long as magnetometer and airspeed data are available and valid. Magnetometer Failure If the magnetometer input fails, the AHRS transitions to one of the reversionary No-Magnetometer modes and continues to output valid attitude information. However, if the aircraft is airborne, the heading output on the PFD does become invalid (as indicated by a red "X"). Air Data Input Failure Failure of the air data input has no affect on the AHRS output while AHRS is receiving valid GPS information. Invalid/unavailable airspeed data in addition to GPS failure results in loss of all attitude and heading information. GPS Receiver Operation Each GIA 63W Integrated Avionics Unit (IAU) contains a GPS receiver. Information collected by the specified receiver (GPS 1 for the #1 IAU or GPS 2 for the #2 IAU) may be viewed on the GPS 1 or GPS 2 Status Pane and the GPS Status Screen on the Touchscreen Controller (refer to Figure 1-29). These GPS sensor annunciations are most often seen after system power-up when one GPS receiver has acquired satellites before the other, or one of the GPS receivers has not yet acquired an SBAS (Satellite Based Augmentation System) signal. While the aircraft is on the ground, the SBAS signal may be blocked by obstructions causing one GPS receiver to have difficulty acquiring a good signal. Also, while airborne, turning the aircraft may result in one of the GPS receivers temporarily losing the SBAS signal. If the sensor annunciation persists, check for a system failure message by touching the MSG Button on Touchscreen Controller. If no failure message exists, check the GPS Status Screen and compare the information for GPS 1 and GPS 2. Discrepancies may indicate a problem. FLIGHT MANAGEEMMEENT HAZARD AVOIDANCE AFCS ADDITIONAL FEATURES APPENDICES INDEX 190-01263-01 Rev. A Garmin G2000 Pilot's Guide for the Cessna T240 37