TM 1–1520–238–T–3
Change 4
12–9
12–26 SIGNAL NAME:
PLT TRIG 2ND DET (ACY) PLT TRIG 1ST DTT (ACZ)
MEMORY LOCATION: 001554
MEMORY DATA BIT(S):
16
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Indicates pilot has pulled cyclic stick weapons action switch trigger to 2nd
detent.
REMARKS: From pilot cyclic stick weapons action switch through pilot FCP and RH FAB MRTU Type
I to FCC.
PASS:
If second digit displayed on HOD is 1, 3, 5, or 7, go to failure symptom index and next failure
symptom paragraph.
FAIL: Location of fault: pilot cyclic stick weapons action switch, wiring from pilot cyclic stick weapons
action switch to pilot FCP, pilot FCP,wiring from pilot FCP to RH FAB MRTU Type I, RH FAB
MRTU Type I. Troubleshoot wiring to isolate fault (TM 9–1090–208–23–2).
12–27 SIGNAL NAME:
CPG I BEAM TYPE
MEMORY LOCATION: 000664
MEMORY DATA BIT(S):
18
(BINARY)
CONDITION:
If the first digit is 0, 1, 4, or 5=SOLID
If the first digit is 2, 3, 6, or 7=OPEN
SIGNAL FUNCTION:
Selects solid or open I beam.
REMARKS: From FCC to symbol generator.
PASS:
If first digit displayed on HOD corresponds to selected I BEAM, go to paragraph 12–28.
FAIL: Location of fault: wiring from DEU to RH FAB MRTU Type I, RH FAB MRTU Type I, for IHADSS
related discrepancies; TADS/PNVS Turret Assembly, wiring from TADS/PNVS Turret Assembly
to TEU, TEU, wiring from TEU to CPG MRTU Type III, CPG MRTU Type III, for TADS related
discrepancies; TADS/PNVS Turret Assembly, wiring from TADS/PNVS Turret Assembly to TEU,
TEU, wiring from TEU to LH FAB MRTU Type I, LH FAB MRTU Type I, wiring from TADS/PNVS
Turret Assembly to PEU, for PNVS related discrepancies. Troubleshoot wiring to isolate fault.
Refer to TM 9–1270–221–23 for integrated helmet and display sight system (IHADSS),
TM 1–5855–265–T for pilot night vision sensor (PNVS), or TM 1–1270–476–T for target
acquisition designation sight (TADS) related discrepancies.
12–28 SIGNAL NAME:
CPG I BEAM CTL
MEMORY LOCATION: 000664
MEMORY DATA BIT(S):
19
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Controls I beam symbol displayed on HOD.
REMARKS: From FCC to symbol generator.
PASS:
If first digit displayed on HOD is 1, 3, 5, or 7, go to paragraph 12–29.
FAIL: Location of fault: wiring from DEU to RH FAB MRTU Type I, RH FAB MRTU Type I, for IHADSS
related discrepancies; TADS/PNVS Turret Assembly,wiring from TADS/PNVS Turret Assembly
to TEU, TEU, wiring from TEU to CPG MRTU Type III, CPG MRTU Type III, for TADS related
discrepancies; TADS/PNVS Turret Assembly, wiring from TADS/PNVS Turret Assembly to TEU,
TEU, wiring from TEU to LH FAB MRTU Type I, LH FAB MRTU Type I, wiring from TADS/PNVS
Turret Assembly to PEU, for PNVS related discrepancies. Troubleshoot wiring to isolate fault.
Refer to TM 9–1270–221–23 for integrated helmet and display sight system (IHADSS),
TM 1–5855–265–T for pilot night vision sensor (PNVS), or TM 1–1270–476–T for target
acquisition designation sight (TADS) related discrepancies.
