Line replaceable unit LRU

LRU Also known as.

line-replaceable unit (LRU). lower line-replaceable unit(LLRU). line-replaceable component (LRC).line-replaceable item (LRI).

Definition

An LRU is an essential support item which is removed and replaced at the field level to restore the end item to an operational ready condition. Conversely, a non-LRU is a part, component, or assembly used in the repair of an LRU / LLRU, when the L.R.U has failed and has been removed from the end item for repair.

An LLRU is part of an LRU, and which can be removed and replaced at the field level to restore its L.R.U to an operational ready condition. As an L.R.U is considered the ‘parent’, the LLRU is considered a ‘child’. An LLRU can also be a child of a child–that is, an LLRU being a component of a higher-level LLRU. However, there is no hierarchy difference between child levels; the only hierarchical separation is parent versus child.

LRU line replaceable unit

L.R.U is a modular component of an airplane,  that is designed to be replaced quickly at an operating location. An L.R.U is usually a sealed unit such as a radio or other auxiliary equipment. L.R.Us are typically assigned logistics control numbers (LCNs) or work unit codes (WUCs) to manage logistics operations.

LRUs improve maintenance operations, because they can be stocked and replaced quickly from on-site inventory, restoring the system to service, while the failed (unserviceable) L.R.U is undergoing maintenance. L.R.U can be exchanged for a replacement part in a relatively short time by only opening and closing fasteners and connectors.