The ECU is switched off until it receives discrete A/C PWR CTL at ECU J2-65 from the CI.
(2) +28 Vdc Main. When ASE 30A CB is closed on the Mission AC/DC Power Cabinet and AAR-57 20A
CB is closed on the Mission Control Panel, +28 Vdc is applied to 10A AAR-57 SQUIB CB and 7.5A AAR-57 DC CB
on the ECU Service Panel.
(3) +28 Vdc Squib CB Distribution. When 10A AAR-57 SQUIB CB on the ECU Service Panel is closed,
the +28 Vdc squib power is distributed to K2 Squib Relay. The SQUIB 10A CB on the ECU Service Panel dis-
tributes +28 Vdc from the aircraft to K2 Squib Power Relay that is activated when signal SQUIB ENABLE from
the CMWS Safe/Arm Control Panel is +28 Vdc. When relay K2 closes +28 Vdc squib power is applied to the
Sequencer. However, WOW Relay K1 in the CMWS Safe/Arm Control Panel controls the distribution of a +28 Vdc
SQUIB ENABLE signal to the K2 Squib Power Relay. WOW Relay K1 is activated when weight is off wheels, but
the SAFE/ARM switch on the CMWS Safe/Arm Control Panel, SAFETY PIN receptacle on the CMWS Safe/Arm
Control Panel, and the SAFETY SWITCH on the right wing in series with each other can cut off distribution of power
(signal +28 Vdc ARM) to pin A2 of K1.
(4) +28 Vdc CB Distribution. When the 7.5A AAR-57 DC CB on the ECU Service Panel is closed, +28
Vdc is distributed as primary power to the CI, ECU, CMWS Safe/Arm Control Panel, and Sequencer (via CMWS
Safe/Arm Control Panel).
(5) +12 Vdc. Part of the +28 Vdc CB distribution goes to Ethernet port plug 9530J3 pin 1. When the plug is
connected to an Ethernet device, +28 Vdc is wrapped around via pin 2 to a +12 Vdc Regulator VR1 where the +28
Vdc is converted to +12 Vdc and provided back to the plug.
4-3. AAR-57 CMWS OPERATION.
The system design is to passively detect IR guided missile threats, by their UV signature, and actively dispense Ad-
vanced Infrared Counter-Measure (AIRCM) lare decoys automatically. Should the aircraft be engaged by RADAR
guided missile threats, as displayed on the APR-39/APR-44 set, the crew will have to manually dispense chaff de-
coy(s) via the control wheel chaff dispense switch. The CI and SACP provide the crew with interface and control of
a. Utilize the CI to:
Power OFF/ON and TEST the system.
(2) Conirm the aircraft identiication number (ACID), CMWS Operational Flight Program (OFP) version,
Mission Data File (MDF) version, and the Sequencer OFP version during initial start-up.
Select and Run Built-In Tests (BIT) and view BIT results.
Conirm, evaluate, and monitor ICMD inventory.
(5) Conirm system conigured for automatic lare or manual chaff dispense by illumination of the "R",
inside top half of the Threat Quadrant Indicator.
(6) Evaluate threat status after threat declaration. The "D", inside lower half of Threat Quadrant Indicator,
remains illuminated while the threat is active and extinguishes when the threat is defeated.
b. Utilize the SACP to:
Safe the system by inserting the Safety pin. Prepare to ARM the system by removing the safety pin.
(2) Safe or Arm the system by selecting the appropriate position on the SAFE/ARM switch. The SACP
SAFE/ARM switch should be the last switch moved to enable protection ("R" illuminated on the CI) and the irst
switch moved to disable protection ("R" extinguished on the CI).