TM 1–1520–238–T–3
Change 4
7–17
7–59 SIGNAL NAME:
CPG J DIR COS
MEMORY LOCATION: 001576
MEMORY DATA BIT(S):
4–19 (ACY) 4–15 (ACZ)
(SCALAR)
CONDITION:
Monitor CPG J direction cosine signal polarity on HOD as TADS is moved up (+) or
down (–) relative to TADS fixed forward position (0).
SIGNAL FUNCTION:
Generates CPG IHADSS J direction cosine.
REMARKS: From SEU through RH FAB MRTU Type I to FCC.
PASS:
If condition is met go to paragraph 7–60.
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).
7–60 SIGNAL NAME:
CPG K DIR COS
MEMORY LOCATION: 001577
MEMORY DATA BIT(S):
4–19 (ACY) 4–15 (ACZ)
(SCALAR)
CONDITION:
Monitor CPG K direction cosine signal polarity on HOD as TADS lens assembly is
moved forward (–) or backwards (+) relative to TADS focal plane (0).
SIGNAL FUNCTION:
Generates CPG IHADSS 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 RH FAB.
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).
7–61 SIGNAL NAME:
PLT GRAY SCALE SW (ACY)
MEMORY LOCATION: 001120
MEMORY DATA BIT(S):
9
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Selects grey scale for helmet mounted display (HMD) calibration.
REMARKS: From pilot FCP through LH FAB MRTU Type I to FCC.
PASS:
If fourth digit on HOD is 0, 1, 4, or 5, go to 7–62.
FAIL: Location of fault: pilot FCP, wiring from pilot FCP to LH FAB MRTU Type I, LH FAB MRTU Type
I. Troubleshoot wiring to isolate fault (TM 9–1270–221–23).
7–62 SIGNAL NAME:
PLT CPG VIDEO SW (ACY)
MEMORY LOCATION: 001120
MEMORY DATA BIT(S):
8
(BINARY)
CONDITION:
If fourth digit on HOD is 2 or 3=CPG
If fourth digit on HOD is 6 or 7=PILOT
SIGNAL FUNCTION:
Selects pilot or CPG video.
REMARKS: From pilot FCP through LH FAB MRTU Type I to FCC.
PASS:
If fourth digit on HOD is 0, 1, 4, or 5, go to Chapter 15, paragraph 15–63.
FAIL: Location of fault: pilot FCP, wiring from pilot FCP to LH FAB MRTU Type I, LH FAB MRTU Type
I. Troubleshoot wiring to isolate fault (TM 9–1270–221–23).
