1–1 FAULT DETECTION AND LOCATION SYSTEM 1–1 (FD/LS)

TM 1–1520–238–T–1 1–2 Change 5 1–1 FAULT DETECTION AND LOCATION SYSTEM 1–1 (FD/LS) – GENERAL Section I. GENERAL INFORMATION 1–1 FAULT DETECTION AND LOCATION SYSTEM (FD/LS) – GENERAL. FD/LS is a method of automatically performing a built-in-test of various systems/line replaceable units (LRUs). Flight crew and maintenance personnel are provided with continuous monitoring of flight critical and mission essential systems, and keyboard initiated system testing. Faults are isolated to the malfunctioning system and LRUs. Various aircraft controls, displays, and indicators interface with FD/LS providing caution/warning advisory information and the media for operator interaction. FD/LS is a software module which resides within the fire control computer (FCC). The FCC is considered the primary bus controller and must be on-line to execute FD/LS functions. The back-up bus controller (BBC) contains a limited version of system fault detection. 1–2 MAJOR FUNCTIONS. a. Provides caution/advisory displays, warning displays, and audible tones while monitoring flight critical and mission essential equipment performance. b. Detects failed systems during flight and ground operations. c. Isolates down to the aviation unit maintenance (AVUM) replaceable LRU. d. Displays operational status (GO/NO-GO) of the systems that interface with the multiplex (MUX) bus.