G1000 Supplemental Maintenance Manual Page 9-7Textron Nav III Series Revision 3190-02128-049.5 GPS Failure TestBefore starting this test, create a simple Direct-To flight plan to an airport or other waypoint thatis greater than 31 NM from the present aircraft position. Verify that the phase of flight displayedon the GPS CDI is ENR.Step Desired ResultSingle GPS Failure Condition:1. Ensure GPS satellites are acquired.2. Place a shroud over the GPS antenna for GIA 1to prevent signal reception. Verify loss of signalon MFD Aux – GPS Status page.3. Check for desired results.4. Remove shroud from the GIA 1 GPS antennaand allow system to re-acquire satellites.5. Place a shroud over the GPS antenna for GIA 2to prevent signal reception. Verify loss of signalon MFD Aux – GPS Status page.6. Check for desired results.7. Remove shroud from the GIA 2 GPS antenna.For each of the single GPS failure conditions, the followingshall remain valid on the PFD throughout the procedure:• Attitude and Heading from AHRS.• Airspeed, Altitude, Vertical Speed, and OAT from AirData Computer.• GPS Course Deviation IndicatorDual GPS Failure Condition:1. Ensure GPS satellites are acquired.2. Cover both GPS antennas. Verify loss of signalon Aux – GPS Status page.3. Check for desired results.4. Remove shrouds from GPS antennas.5. Allow both receivers to re-acquire satellitesignals before continuing.For a dual GPS failure condition, the following shall occur:• GPS CDI flags LOI on the PFD.• Attitude and Heading remain valid from both AHRSon the PFD.• Airspeed, Altitude, Vertical Speed and OAT remainvalid from both Air Data Computers on the PFD.• LOI appears on MFD Map.• TAWS N/A aural alert & annunciation given.When GPS satellites are re-acquired, verify that the INTEGOK annunciation is given on the HSI in white for a briefperiod of time then disappears.After ~10 seconds of stable GPS position reacquisition,verify the TAWS AVAILABLE aural alert is given.Verify that the system returns to normal navigation mode(GPS CDI restored, LOI annunciation removed, & GPSdata magenta).
