APPENDIX B MAINTENANCE ALLOCATION CHART

TM 55-4920-413-13&P APPENDIX B MAINTENANCE ALLOCATION CHART Section L INTRODUCTION B-1. MAINTENANCE ALLOCATION CHART. a. This Maintenance Allocation Chart (MAC) as- signs maintenance functions in accordance with the Three Levels of Maintenance concept for army aircraft. These maintenance levels Aviation Unit Maintenance (AVUM), Aviation Intermediate Maintenance (AVIM) and Depot Maintenance are depicted on the MAC as: AVUM WHICH CORRESPONDS TO THE O CODE IN THE REPAIR PARTS AND SPECIAL TOOLS LIST (RPSTL) AVIM WHICH CORRESPONDS TO THE F CODE IN THE REPAIR PARTS AND SPECIAL TOOLS LIST (RPSTL) DEPOT WHICH CORRESPONDS TO THE D CODE IN THE REPAIR PARTS AND SPECIAL TOOLS LIST (RPSTL) b. The maintenance to be performed below depot and in the field is described as follows (1) Aviation Unit Maintenance (AVUM) - AVUM activities will be staffed and equipped to perform high frequency “On-Equipment” mainte- nance tasks required to retain or return equipment to a serviceable condition. The maintenance capability of the AVUM will be governed by the MAC and limited by the amount and complexity of support equipment, facilities required, and number of spaces and critical skills available. The range and quantity of authorized spare modules/components will be consistent with the mobility requirements dictated by the air mobility concept. (Assignment of maintenance tasks to divi- sional company size aviation units will consider the overall maintenance capability of the division, the requirement to conserve personnel and equipment resources and air mobility requirements ). (a) Company Size Aviation Units Perform those tasks which consist primarily of preventive maintenance and maintenance repair and replacement functions associated with sustaining a high level of equipment operational readiness. Perform maintenance inspections and servicing to include daily, intermedi- ate, periodic and special inspections as authorized by the MAC or higher headquarters. Identify the cause of equipment/system malfunctions using applicable technical manual troubleshooting instructions, Built-In- Test Equipment (BITE ), installed instruments, or easy to use Test Measurement and Diagnostic Equipment (TMDE). Replace worn or damaged modules/comp- nents which do not require complex adjustments or system alignment and which can be removed/installed with available skills, tools and equipment. Perform operational and continuity checks and make minor repairs. Perform servicing, functional adjustments, and minor repair/replacement. Evacuate unserviceable modules/components and end items beyond the repair capability of AVUM to the supporting AVIM. (b) Less than Company Size Aviation Units: Aviation elements organic to brigade, group, battalion headquarters and detachment size units are normally small and have less than ten aircraft assigned. Main- tenance tasks performed by the aircraft crew chief or assigned aircraft repairman will normally be limited to preventive maintenance, inspections, servicing, spot painting, stop drilling, minor adjustments, module/ component fault diagnosis and replacement of selected modules/components. Repair functions wil normally be accomplished by the supporting AVIM unit. B-2. USE OF THE MAINTENANCE ALLOCATION CHART. a. The MAC assigns maintenance functions to the lowest level of maintenance based on past experience and the following consideration: (1) Skills available. (2) Time required. (3) Tools and test available. equipment required and/or b. Only the lowest level of maintenance authorized to perform a maintenance function is indicated. If the lowest level of maintenance cannot perform all tasks of B-1