Garmin G1000 NAV III Line Maintenance Manual page 142

4.3.7.2 VHF COM Interference Test
This test must be conducted outside. Use of a GPS repeater inside a hangar may result in a failed test. Once the
signal acquisition test from Section 4.3.5.1 has been completed successfully, perform the following steps:
1. On the MFD, monitor GPS signal strength bars on the 3
2. On the PFD, ensure that the CDI is set to GPS. If it is not, press the 'CDI' softkey until GPS ENR is
displayed.
3. Verify that the GPS "INTEG" flag is out of view (see Figure 2-1).
4. Select 121.150 MHz on the No. 1 COM transceiver.
5. Transmit for a period of 30 seconds while monitoring GPS 1 signal strength levels.
6. During the transmit period, verify that the GPS "INTEG" flag does not come into view on the PFD and
verify that GPS 1 does not lose a 3-D navigation solution on the MFD.
7. Repeat steps 5-6 and re-transmit while monitoring GPS 2 signal levels on the MFD.
8. Repeat steps 4 through 7 for the following frequencies:
•
121.175 MHz
•
121.200 MHz
•
131.250 MHz
•
131.275 MHz
•
131.300 MHz
9. Repeat steps 4 through 8 for the No. 2 COM transceiver (GIA2).
10. On the MFD, select the 4
11. Under the COM CONFIG field, change the COM channel spacing from 25 kHz to 8.33 kHz.
12. Go back to the 3
13. Select 121.185 MHz on the No. 1 COM transceiver (GIA1).
14. Transmit for a period of 35 seconds while monitoring GPS 1 signal strength levels.
15. During the transmit period, verify that the GPS "INTEG" flag does not come into view on the PFD and
verify that GPS 1 does not lose a 3-D navigation solution on the MFD.
16. Repeat steps 14 and 15 while monitoring the GPS 2 (GIA2) signal levels on the MFD.
17. Repeat steps 14 through 16 for each of the following frequencies:
•
121.190 MHz
•
130.285 MHz
•
131.290 MHz
18. Repeat steps 14 through 17 for the No. 2 COM transceiver (GIA2).
19. On the MFD, select the 4
4.3.7.3 VOR/LOC/GS Test
Check the VOR, ILS, and Glideslope functions with ramp test equipment. Operate the equipment according to
the test equipment manufacturer's instructions. Adjust the RF signal to a level adequate to perform the test. Note
that the PFD CDI will not show a course deviation bar unless a valid VHF nav frequency is tuned. Simulate a
VOR signal on radial 000° with a course-width of 20°. Verify full-scale deflection of the CDI while applying a
10° deviation signal. Exercise the CDI with both right and left deviations for both NAV 1 and 2. Exercise the
Glideslope indicator with up and down deviation indications.
If no other maintenance is required, continue to Section 5.
Page 4-16
Rev. L
th
AUX page.
rd
AUX page.
th
AUX page and change the COM channel spacing back to 25kHz.
rd
AUX page.
G1000 Nav III Line Maintenance Manual
190-00352-00