Operation of the electric trim system should occur only by movement of pairs of switches. Any
movement of the elevator trim wheel while depressing only one switch element indicates a trim
system malfunction. The electric elevator trim control switch must then be turned OFF and light
conducted by operating the elevator trim wheel manually. Do not use autopilot.
(1) ELEV TRIM switch -- ON.
(2) Pilot and copilot trim switches -- Check operation.
(3) Pilot and copilot trim switches -- Check individual element for no movement of trim, then check
proper operation of both elements.
(4) Pilot trim switches -- Check that pilot switches override copilot switches while trimming in
opposite directions, and trim moves in direction commanded by pilot.
(5) Pilot or copilot trim switches -- Check trim disconnects while activating pilot or copilot trim
(6) ELEV TRIM switch -- OFF then ON (ELEC TRIM OFF annunciator extinguishes).
27. COMMON MISSILE WARNING SYSTEM (CMWS) -- BIT checks as required.
a. Safe Arm Control Panel (SACP) -- Set as follows:
(1) Saing pin -- Conirm installed.
(2) ARM/SAFE switch -- SAFE.
(3) JETTISON switch cover -- Down.
(4) ZEROIZE switch cover -- Down.
After installing a UDM, do not abort the ECU power- up and initialization process. This process is
complete when BIT I/P is displayed on the CI. If this process is prematurely aborted, differences
between the UDM and the ECU resident boot data may permanently disable the ECU.
If a UDM is not installed the system will not progress to the BIT I/P message and the system will not
b. CMWS Control Indicator (CI) PWR switch -- ON . Monitor the system for the following audio/visual
(1) Verify the CI Status alphanumeric display and indicators briely light.
(2) Message COMM FAIL is displayed on CI at start- up for approximately 30 seconds -- this is
normal. If COMM FAIL is displayed for longer than 3 minutes, wait another 2 minutes before
aborting the process.
(ICS) and CI displays BIT I/P.
(4) Verify "Missile, Missile" is heard over the ICS.
(5) Verify the 4 CI THREAT quadrant Indicators simultaneously lash twice.
(6) If a fault appears, review and record the XXXX FAIL or XXXX DEGR (ground only) message (s).
Each fault message must be acknowledged.
(7) Toggle the CI PWR switch to TEST and release to display next fault message. Review and
record this message. Continue to toggle the CI PWR switch to TEST and release to page
through all fault messages.
(8) If SYS PASS message appears, the system is mission capable.