Gps Failure Test - Garmin G1000 NXi Supplemental Maintenance Manual

9.5

GPS Failure Test

Before starting this test, create a simple Direct-To flight plan to an airport or other waypoint that
is greater than 31 NM from the present aircraft position. Verify that the phase of flight displayed
on the GPS CDI is ENR.
Step
Single GPS Failure Condition:
1. Ensure GPS satellites are acquired.
2. Place a shroud over the GPS antenna for GIA 1
to prevent signal reception. Verify loss of signal
on MFD Aux – GPS Status page.
3. Check for desired results.
4. Remove shroud from the GIA 1 GPS antenna
and allow system to re-acquire satellites.
5. Place a shroud over the GPS antenna for GIA 2
to prevent signal reception. Verify loss of signal
on MFD Aux – GPS Status page.
6. Check for desired results.
7.
Remove shroud from the GIA 2 GPS antenna.
Dual GPS Failure Condition:
1. Ensure GPS satellites are acquired.
2. Cover both GPS antennas. Verify loss of signal
on Aux – GPS Status page.
3. Check for desired results.
4. Remove shrouds from GPS antennas.
5. Allow both receivers to re-acquire satellite
signals before continuing.
G1000 NXi Supplemental Maintenance Manual
Textron Aviation G36/G58
Desired Result
For each of the single GPS failure conditions, the following
shall remain valid on the PFD throughout the procedure:
•
Attitude and Heading from AHRS.
•
Airspeed, Altitude, Vertical Speed, and OAT from Air
Data Computer.
•
GPS Course Deviation Indicator
For a dual GPS failure condition, the following shall occur:
•
GPS CDI flags LOI on the PFD.
•
Attitude and Heading remain valid from both AHRS
on the PFD.
•
Airspeed, Altitude, Vertical Speed and OAT remain
valid 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 INTEG
OK annunciation is given on the HSI in white for a brief
period 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, & GPS
data magenta).
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