Editing Line-replaceable unit (section)

== Definition ==

While the term LRU has been in use for decades, MIL-PRF-49506, Notice 1 of 18 Jan 05, the Performance Spec for Logistics Management Information defines an LRU as:

<blockquote>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 LRU has failed and has been removed from the end item for repair.</blockquote>

<blockquote>An '''LLRU''' is part of an LRU, and which can be removed and replaced at the field level to restore its LRU to an operational ready condition.  As an LRU 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.</blockquote>