TM 1–1520–238–T–3
20–12
20–27 SIGNAL NAME:
DOP SINE PITCH
MEMORY LOCATION: 000465 AND 000466
MEMORY DATA BIT(S):
16–4 AND 19–18
(SCALAR)
CONDITION:
Monitor HOD; memory location response should indicate a positive if aircraft is in nose
up attitude or a negative if aircraft is in nose down attitude.
SIGNAL FUNCTION:
Indicates Doppler sine pitch.
REMARKS: From Doppler through CPG MRTU Type III to FCC.
PASS:
If CONDITION has been met go to paragraph 20–33.
FAIL: Location of fault: Doppler, wiring from Doppler to CPG MRTU Type III,CPG MRTU Type III.
Troubleshoot wiring to isolate fault (TM 11–1520–238–23–2).
20–28 SIGNAL NAME:
DOP TRACK ANGLE ERROR (–180/+180 DEGREES)
MEMORY LOCATION: 000467
MEMORY DATA BIT(S):
19–18
(BINARY)
CONDITION:
If sixth digit displayed on HOD is 0, and fifth digit is 0, 1, 2, or 3=plus, north
west, up
If sixth digit displayed on HOD is 0, and fifth digit is 4, 5, 6, or 7=failure warning
If sixth digit displayed on HOD is 1, and fifth digit is 0, 1, 2, or 3=no computed data and
no failure detected
If sixth digit displayed on HOD is 1, and fifth digit is 4, 5, 6, of 7=minus, south, east,
down, from
SIGNAL FUNCTION:
Indicates sine/status of Doppler.
REMARKS: From RTA to Doppler. From Doppler through CPG MRTU Type III to FCC.
PASS:
If CONDITION agrees with track angle, go to paragraph 20–29.
FAIL: Location of fault: RTA, wiring from RTA to Doppler, Doppler, wiring from Doppler to CPG MRTU
Type III, CPG MRTU Type III. Troubleshoot wiring to isolate fault (TM 11–1520–238–23–2).
20–29 SIGNAL NAME:
DOP TRACK ANGLE ERROR
MEMORY LOCATION: 000467
MEMORY DATA BIT(S):
17–16
(BINARY)
CONDITION:
0 through 3 displayed
SIGNAL FUNCTION:
Indicates hundreds field.
REMARKS: From Doppler through CPG MRTU Type III to FCC.
PASS:
If CONDITION agrees with track angle, go to paragraph 20–30.
FAIL: Location of fault: Doppler, wiring from Doppler to CPG MRTU Type III, CPG MRTU Type III.
Troubleshoot wiring to isolate fault (TM 11–1520–238–23–2).
