text: Chapter 4
  Army Aviation Sustainment
  SECTION I – OVERVIEW
  4-1. This chapter addresses aviation sustainment requirements and the capabilities aviation provides to
  support the force. It focuses on the aviation specific details of the sustainment warfighting function and
  elements of sustainment—logistics, personnel support, HSS—and their impact on aviation operations.
  4-2. Sustaining Army Aviation units in complex environments requires a logistics network capable of
  projecting and providing the support and services necessary for extended operations in order to support the
  ground maneuver commander through the entire range of military operations. While conducting aviation
  sustainment operations, aviation commanders and staffs must adhere to sustainment principles: integration,
  anticipation, responsiveness, simplicity, economy, survivability, continuity, and improvisation (ADP 4-0,
  ATP 3-04.7, and ATP 4-33). These imperatives apply across the conflict continuum to units conducting
  offense, defense, and stability operations.
  4-3. By employing effective sustainment operations, aviation commanders have the combat power
  necessary to support decisive action essential to retaining and exploiting the initiative. For this reason,
  sustainment must be planned and synchronized at every level of the operation. Commanders must know the
  OE, understand requirements, track requisitions, and make crucial decisions ensuring responsive
  sustainment. LSCO heavily tax aviation sustainment networks, and the continuous generation of aviation
  combat power is one of the commander’s most significant concerns throughout an operation. Successful
  aviation sustainment in LSCO require redundant LOCs, well-trained processes, and commanders and staffs
  knowledgeable in the above-listed sustainment principles.
  SECTION II – MAINTENANCE AND LOGISTICS
  4-4. Army Aviation maintenance is a primary focus of the aviation commander, as it drives the
  availability of operational aircraft that can be used in support of the ground maneuver commander’s
  operational requirements. It also determines the level of tactical mission support each aircraft is able to
  perform during mission execution. An efficient, properly resourced maintenance program provides the
  maximum number of aircraft available on a consistent basis for mission support, thus increasing combat
  power. For more information on aviation maintenance, see ATP 3-04.7.
  4-5. Aircraft are generally limited by scheduled inspections at prescribed flight hour intervals. In order to
  provide the commander operational flexibility, the maneuver companies, AMC, and ASC must be
  organized and directed to perform scheduled maintenance well in advance of an operation. They must also
  prepare to perform unscheduled maintenance forward. The accepted goal for aircraft bank-time is generally
  50 percent. The AMC and ASC should expect to drive the unit bank-time as high as possible in the
  preparation phase of a significant operation. This ultimately provides the commander more flexibility and
  allows the AMC to focus efforts on unscheduled maintenance, repairing aircraft, and preserving combat
  power.
  FIELD-LEVEL MAINTENANCE
  4-6. Field-level maintenance is accomplished throughout the CAB by aviation companies and AMCs in
  maneuver battalions and by the ASC in the ASB.
  4-7. Aviation maneuver companies perform scheduled maintenance with assigned maintenance personnel.
  They also perform unscheduled field maintenance on assigned manned and unmanned aircraft provided that