TM 1-1520-238-10 2-75 e. Inspection and Maintenance Light. The in- spection and maintenance light is stored in the left equip- ment stowage compartment (fig 2-2). Two plug-in recep- tacle locations provide electrical power and will facilitate inspection and maintenance at all points on the helicopter. The receptacle is located adjacent to the CPG station on the underside of the right FAB, forward of the searchlight (fig 2-2). The second receptacle is located in the right aft avionics bay (fig 2-2). Power for operating the light is 24 vdc directly from the battery through the MAINT LT circuit breaker in the right aft avionics bay. Operation of the in- spection and maintenance light is controlled by an OFF- BRT rheostat switch which is integral with the light. 2.49.2 Interior Lighting System. The helicopter interi- or lighting system consists of dimming lighting for engine instruments, flight instruments, avionics panels, console panels, and circuit breaker panels. All engine and flight in- struments are equipped with red surface mounted edge lighting fixtures, and the avionics console and circuit breaker panel lights are integrally illuminated. Light is re- flected to illuminate the panel markings and the clear edg- ing around each switch or circuit breaker. In the event of total electrical power generation failure, the pilot and CPG flood lights, utility lights, and searchlight remain operable through the dc emergency bus. a. Pilot Interior Lighting. Interior lighting for the pi- lot is controlled by three switch/rheostats and a three- position FLOOD toggle switch located on the pilot INTR LT control panel. The three switch/rheostats provide a de- tented OFF position and dim to BRT position. AC voltage is the primary power for the interior lights. The ac voltage is applied to a multichannel dimmer assembly through the PRI circuit breaker on the pilot overhead circuit breaker panel. The multichannel dimmer converts 115 vac to the proper dc levels for the three switch/rheostats. The INST, L CSL, and R/CTR CSL switch/rheostats vary the multi- channel dimmer output. The INST switch/rheostat con- trols channels 1 and 2 of the multichannel dimmer. Chan- nel 1 is for the right instrument panel, and channel 2 is for the left instrument panel. Both channels vary the multi- channel output from OFF position to BRT. The R/CTR CSL control is split into two sections; A: OFF position, and BRT for APU FIRE TEST and APX100 control panel. B: OFF position, and BRT for the avionics control box lights in the center and right console. The L CSL controls the cir- cuit breaker panels and the collective stick grip lights. The pilot also has an EDGE LT PNL ON/OFF switch located on the overhead circuit breaker panel that allows him to turn off circuit breaker edge lights independent of other console lights. b. CPG Interior Lighting. The CPG interior lighting operation of the INTR LT switch/rheostats and the multi- channel dimmer are the same as for the pilot operation. The INST switch/rheostat controls outputs to channel 1 (right side instruments), channel 2 (left side instruments), and the ORT. The R CSL controls outputs to channel 3 which is split into sections A and B. A: to the avionics lights; B: to the ASN 128 panel lights. The L CSL controls the circuit breaker and collective stick grip lights. c. Emergency Floodlight System. The emergen- cy floodlight system is installed under the glareshields of the pilot and CPG instrument panels. Power for the emer- gency floodlight system is emergency bus 28 vdc power through the UTIL SEC circuit breaker on the pilot over- head circuit breaker panel and the UTIL SEC LT circuit breaker on the CPG main circuit breaker panel (fig 2-40). Operation of the emergency floodlight system is con- trolled by the FLOOD three-position toggle switch on the pilot and CPG INTR LT control panel. When the switch is positioned to the BRT position, it turns on the blue green secondary lights to the brightest level. When in the dim position, the secondary lighting is dimmed. d. Utility Light. A detachable utility light with a coiled extension cord is located to the left of the pilot and CPG seats. The utility light provides emergency red or white lighting in case instrument panel lighting fails. The light is operated by an OFF BRT rheostat switch integral with the light. Rotating the front section of the light selects white flood or red flood. The utility light receives 28 vdc from the emergency dc bus through the UTIL SEC LT cir- cuit breaker on the pilot overhead circuit breaker panel and the UTIL SEC LT circuit breaker on the CPG No. 1 circuit breaker panel. e. Dimming, MASTER CAUTION Panel, and Cau- tion/Warning Panel Advisory Segment Lights. Dim- ming of all caution/warning lights is controlled by the INST control on both the pilot and CPG INTR LT control panels for the respective crew station. When the INST control is is in the OFF position, caution/warning lights are bright; any other position will cause the respective lights to go to a preset dim condition.