Gtx Test - Garmin GTX 330 System Maintenance Manual

8.4

GTX TEST

Operation of the GTX 330/330D/33 or 33D Mode-S transponder is accomplished using either the
faceplate of the unit (on the GTX 330 series See Section 3.1) or a GTN 6XX/7XX unit (on the GTX 33
series). Refer to the operational documents listed in Table 2 and Table 3 for basic GTX 33 series
operation.
The integrated transponder/altitude reporting system must be verified in accordance with Title 14 of the
Code of Federal Regulations (14 CFR) §§ 91.411 and 91.413, every 24 calendar months, or any time the
transponder is removed/replaced/modified.
Additionally, the ADS-B Out parameters must be verified in accordance with Title 14 of the Code of
Federal Regulations (14 CFR) § 91.227 any time the position source (GPS) is replaced/modified.
The test is typically done as a ramp test using a transponder ramp test set, such as the IFR ATC-601A or
TIC TR-220 (S/W v5.30 or later). Specific instructions for operating the ramp tester are contained in the
applicable operator's manual.
Reference Part 43 Appendix F for testing criteria. The ramp test includes checks as follows:
1. Reply Frequency
2. Suppression
3. Receiver Sensitivity
4. Reply RF Output Power
5. Mode S Diversity Channel Isolation (if applicable)
6. Mode S Address
7. Mode S Formats
8. Mode S All-Call
9. ATCRBS –Only All Call
10. Squitter
Reference AC 43-6B and 14 CFR Part 43, Appendix E (c) for testing criteria. The ramp test includes
checks as follows:
1. Altitude Reporting
Reference Advisory Circular 20-165A and 14 CFR Part 91.227 for the following ADS-B Out parameters:
≥ 8
1. NAC
P
2. NIC ≥ 7
3. NACv ≥ 1
4. SIL ≥ 3
5. SDA ≥ 2
6. Ensure all 14 CFR 91.227(d) parameters are populated and transmitted.
If no other service is to be performed, continue to the return-to-service checks in Section 9.
GTX 330/33 with ADS-B Out
Maintenance Manual with ICA
The document reference is online, please check the correspondence between the online documentation and the printed version.
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