TM 1-1520-238-T-6
9–100
9–7.
SYSTEM DESCRIPTION (cont)
9–7
(14) Pilot Caution/Warning System.
The pilot caution/warning system (fig. 9–93) provides indications of
hazardous conditions, master caution indications, master caution resets, audio warning resets and lamp press to
test functions in the pilot station.
(a) LT CAUT circuit breaker (CB21), on the pilot’s center circuit breaker panel, supplies 28 VDC to the
pilot matrix module. FIRE DETR APU circuit breaker (CB11), on the pilot’s center circuit breaker panel, supplies
28 VDC to the pilot APU fire test panel. FIRE DETR ENG 1 circuit breaker (CB12), on the pilot’s center circuit
breaker panel, supplies 28 VDC to the multi-channel dimming controller. FIRE DETR ENG 2 circuit breaker
(CB13), on the pilot’s center circuit breaker panel, supplies 28 VDC to the multi-channel dimming controller.
(b) The multi-channel dimming controller receives engine fire detection, APU fire detection, tail wheel
unlock, anti-ice, engine starter and engine overspeed inputs to provide indications of caution and warning
conditions on the applicable remote indicator lights. When the PRESS TO TEST indicator on the pilot’s master
caution/warning panel is pressed, the multi-channel dimming controller outputs voltage to light the following
remote indicators:
Pilot BTL DISCHARGE indicators.
Pilot fire extinguisher ENG FIRE PULL handles.
Pilot ANTI ICE indicators.
Pilot power quadrant indicators.
Pilot TAIL WHEEL indicator.
Pilot EMERG PWR CHK OVSP TEST panel indicators.
Pilot remote transmitter selector indicator panel indicators.
Radar warning display MA indicator.
Radar warning control SELF-TEST indicator.
Pilot ARM/SAFE indicators (through the CPG and pilot fire control panels).
(c) The pilot matrix module supplies 28 VDC to the pilot master caution/warning panel and the pilot
caution/warning panel. The pilot matrix module also supplies 0 to 5 VDC edge-lighting to the pilot caution/warning
panel. When the PRESS TO TEST indicator on the pilot’s master caution/warning panel is pressed, the pilot
matrix module outputs voltage to enable the tail rotor gearbox temp alarm and to light the pilot ROCKETS control
panel remote indicators. The pilot matrix module supplies 28 VDC to the CPG isolation relay. When an APU fire is
detected the APU flame detector supplies a ground to the CPG isolation relay enabling the FIRE APU master
caution/warning indicators.
(d) The pilot caution/warning panel receives inputs from the CPG caution/warning panel and DASE to
provide indications of caution and warning. The pilot caution/warning panel outputs 28 VDC to the master
caution/warning panel for reset voltage and caution and warning indicators. The pilot caution/warning panel also
outputs 5 VDC to the master caution/warning panel for PRESS TO TEST indicator voltage.
(e) The MASTER CAUTION light on the pilot’s master caution/warning panel lights when a n indicator
on the pilot’s caution/warning panel lights. The PRESS TO TEST indicator on the pilot’s master caution/warning
panel tests (lights) caution/warning panel indicators and all remote caution/warning indicators. Pressing ENGINE
1 OUT or ENGINE 2 OUT indicator resets the audio alarms from the engine out warning unit.
