Loss of Ground Data Reception by the ATSU

TASK 46-21-00-810-828-A
Loss of Ground Data Reception by the ATSU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-12-33-000-001	Removal of the VHF Transceiver
AMM 23-12-33-400-001	Installation of the VHF Transceiver
AMM 46-21-00-710-002	VHF 3 Link Test of the ATSU
ASM 462105
AMM 46-21-34-000-001	Removal of the Air Traffic Service Unit (ATSU)
AMM 46-21-34-400-001	Installation of the Air Traffic Service Unit (ATSU)

3. Fault Confirmation
Subtask 46-21-00-740-102-A

A. Test
(1) Do the VHF3 Link Test AMM 46-21-00-710-002.

NOTE: Set the frequency of the ground station.

4. Fault Isolation
Subtask 46-21-00-810-076-A

A. If the test gives the FAILED indication:

(1) If the fault continues:

(a) If the fault continues:

do a check and repair the wiring of the VDR/3 INPUT BUS from the VDR3 (1RC3) pins AB/10C,10D to the ATSU (1TX1) pins AA/4J,4K ASM 462105.

Subtask 46-21-00-740-103-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:19 UTC