1–5 FD/LS OPERATION – GENERAL (cont)

TM 1–1520–238–T–1 Change 5 1–13 1–5 FD/LS OPERATION – GENERAL (cont) 1–5 NOTE · Control/switch position changes prompted by FD/LS must be performed within 30 seconds of prompt or false NO-GO message is displayed. · The FD/LS message on the HOD changes within 2 seconds after responding to a prompt (acknowledgement). (3) Prompts and advisory messages are displayed on the HOD when specific interactive operator actions are required. These messages direct the operator to perform operations required by the systems tests. (4) Test-in-progress messages are automatically displayed on the HOD to inform operators that a specific test requires additional time to complete. (5) The operator is prompted through each test, until all tests are completed. (6) The operator has the option to pass or abort any test and continue forward to the next test during the ETE check. Pressing and releasing the ENTER SPACE key on the DEK (ADC) or SPC key on the CDU (ADD) executes the operators options. (7) The pass/abort mode during the ETE check is inhibited only if a prompt or advisory message is displayed. e. Boresight Corrector FD/LS Display for GUN, PYLON, TADS (target acquisition designation sight), and PNVS (pilot night vision sensor). NOTE The loss or significant reduction in the FCC battery voltage could cause loss of all data in random access memory (RAM), including boresight correctors. If FCC battery voltage is suspect, refer to TM 9-1230-476-20-2 (ACY). If FCC LOAD (ACZ) or FCC LOAD FAIL, BST DATA LOAD FAIL, INIT DATA LOAD FAIL (ADD) message appears, perform boresight editing procedures TM 9-1230-476-20-1. (1) FD/LS provides checksum error checking of the boresight correctors for GUN, PYLONS, TADS, and PNVS in both the continuous and maintenance modes. Arithmetic checking takes place during program execution of the software to prevent unexpected changes or alterations to this data which could cause gross errors in pointing/aiming of these systems.