TM  1-1520-240-10 4-1-18            CONTROLS/ INDICATOR FUNCTION DSPL POS D/U/ L/R Pilot’s control for display position down/up (outer knob) and left/right (inner knob). MODE 1-4/DCLT Switch Three position toggle switch spring-loaded to off. Changes the pilot’s primary mode and/or primary mode’s decluttered display. refer to paragraph 4-1-36 for detailed procedures. ADJ/ON/OFF Switch Three position switch. Selects adjust mode, enabling the INC/DEC switch to adjust,altitudes, pitch or roll. Turns power on/off to HUD system. FAIL Light Illuminates to indicate a system failure. ON Light Illuminates to indicate when system is powered up. P-PGM/OP/CP-PGM Switch Three position switch. Selects pilot program mode, operational mode or copilot program mode. Used with the PGM NXT/SEL switch. BIT/ACK Switch Thee position toggle switch spring-loaded to off. Placed to BIT momentarily, selects built-in-test. Placed to BIT position and held, changes display to symbol generator test mode until switch is released. When placed to CONTROLS/ INDICATOR FUNCTION ACK, used to acknowledge displayed fault, completion of adjustment, or completion of programming sequence. After ACK is used to acknowledge a fault, fault will not appear until BIT is selected or power is cycled off and on. ALT/P/R DEC/INC Switch Thee position toggle switch spring-loaded to off. Active when adjust mode is selected to decrease/increase altitude/pitch/roll. When adjusting altitude (MSL) momentary movement of DEC/INC switch will change data in 5 ft increments. When DEC/INC switch is held for one second, data will change in 10 ft increments. Pitch and roll change in increments of 1 degree. PGM NXT/SEL Thee position toggle switch spring-loaded to off. Active when program mode is selected. Operator can preprogram four normal modes and four declutter modes. Operator selects flashing symbol for display or goes to next symbol. Once complete, operator toggles ACK switch to save programmed display. To program full display, use ACK after changing to new mode.