AO Assembled by unit/AVUM level
Items with these codes are not to be
AF Assembled by DS/AVIM level
requested/requisitioned individually. The parts that
AH Assembled by GS level
make up the assembled item must be requisitioned or
AL Assembled by SFA
fabricated and assembled at the level of maintenance
AD Assembled by depot
indicated by the source code. If the 3rd position of the
SMR code authorizes you to replace the item, but the
source code indicates the item is assembled at a
higher level, order the item from the higher level of
Do not requisition an "XA" coded item. Order the next
higher assembly. (Refer to NOTE below).
If an item is not available from salvage, order it using
the CAGE and P/N.
Installation drawings, diagrams, instruction sheets,
field service drawings; identified by manufacturer's
Item is not stocked. Order an XD-coded item through
normal supply channels using the CAGE and P/N
given, if no NSN is available.
Cannibalization or controlled exchange, when authorized, may be used as a source of
supply for items with the above source codes except for those items source coded "XA"
or those aircraft support items restricted by requirements of AR 750-1.
Maintenance Code. Maintenance codes tell you the level(s) of maintenance authorized to use and repair
support items. The maintenance codes are entered in the third and fourth positions of the SMR code as
Third Position. The maintenance code entered in the third position tells you the lowest maintenance level
authorized to remove, replace, and use an item. The maintenance code entered in the third position will
indicate authorization to the following levels of maintenance:
Crew or operator maintenance done within unit/AVUM maintenance.
Unit level/AVUM maintenance can remove, replace, and use the item.
Direct support/AVIM maintenance can remove, replace, and use the item.
General support maintenance can remove, replace, and use the item.
Specialized repair activity can remove, replace, and use the item.
Depot can remove, replace, and use the item.