TM 1–1520–238–T–3
7–12
Change 4
7–40 SIGNAL NAME:
PLT LOS STATUS (ACY) PLT LOS INVALID (ACZ)
MEMORY LOCATION: 001571
MEMORY DATA BIT(S):
11
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Monitors pilot LOS status.
REMARKS: From SEU through RH FAB MRTU Type I to FCC.
PASS:
If third digit on HOD is 0, 1, 2, or 3, go to Chapter 10, paragraph 10–36.
FAIL: Location of fault: go to paragraph 7–41.
7–41 SIGNAL NAME:
PLT I DIRCOS
MEMORY LOCATION: 001572
MEMORY DATA BIT(S):
4–19 ACY) 4–15 (ACZ)
((SCALAR)
CONDITION:
Monitor pilot I direction cosine signal polarity on HOD as TADS is moved left (–) or right
(+) of TADS fixed forward position (0).
SIGNAL FUNCTION:
Generates pilot I direction cosine.
REMARKS: From SEU through RH FAB MRTU Type I to FCC.
PASS:
If condition is met go to paragraph 7–42.
FAIL: Location of fault: SSU, wiring from SSU to SEU, SEU, wiring from SEU to RH FAB MRTU Type
I, RH FAB MRTU Type I. Troubleshoot wiring to isolate fault (TM 9–1270–221–23).
7–42 SIGNAL NAME:
PLT J DIRCOS
MEMORY LOCATION: 001573
MEMORY DATA BIT(S):
4–19 (ACY) 4–15 (ACZ)
(SCALAR)
CONDITION:
Monitor pilot J direction cosine signal polarity on HOD as TADS is moved up (+) or
down (–) from TADS fixed forward position (0).
SIGNAL FUNCTION:
Generates pilot J direction cosine.
REMARKS: From SEU through RH FAB MRTU Type I to FCC.
PASS:
If condition is met go to paragraph 7–43.
FAIL: Location of fault: SSU, wiring from SSU to SEU, SEU, wiring from SEU to RH FAB MRTU Type
I, RH FAB MRTU Type I. Troubleshoot wiring to isolate fault (TM 9–1270–221–23).
7–43 SIGNAL NAME:
PLT K DIRCOS
MEMORY LOCATION: 001574
MEMORY DATA BIT(S):
4–19 (ACY) 4–15 (ACZ)
(SCALAR)
CONDITION:
Monitor pilot K direction cosine signal polarity on HOD as TADS lens assembly is
moved forward (–) or backward (+) relative to TADS focal plane (0).
SIGNAL FUNCTION:
Generates pilot K direction cosine.
REMARKS: From SEU through RH FAB MRTU Type I to FCC.
PASS:
Location of fault if condition is met: wiring between DEU and MRTU Type I. Troubleshoot
wiring to isolate fault (TM 9–1270–221–23).
FAIL: Location of fault: SSU, wiring from SSU to SEU, SEU, wiring from SEU to RH FAB MRTU Type
I, RH FAB MRTU Type I. Troubleshoot wiring to isolate fault (TM 9–1270–221–23).
7–44 SIGNAL NAME:
IHADSS COMMON VIDEO SELECT
MEMORY LOCATION: 001626
MEMORY DATA BIT(S):
4
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Instructs DEU to select common video input.
REMARKS: From FCC through RH FAB MRTU Type I to DEU.
PASS:
Location of fault if sixth digit on HOD is 1: wiring between DEU and MRTU Type I.
Troubleshoot wiring to isolate fault (TM 9–1270–221–23).
FAIL: Location of fault: DEU, wiring from DEU to RH FAB MRTU Type I, RH FAB MRTU Type I.
Troubleshoot wiring to isolate fault (TM 9–1270–221–23).
