TM 55-4920-429-23P
XA-
Do not requisition an "XA"-coded item. Order its next higher assembly. (Also, refer to the
NOTE below.)
XB-
If an "XB" item is not availabe from salvage, order it using the FSCM and part number given.
XC-
Installation drawing, diagram, instruction sheet, field service drawing, that is identified by
manufacturer's part number.
XD-
Item is not stocked. Order an "XD"-coded item through normal supply channels using the
FSCM and part number given, if no NSN is available.
NOTE: Cannibalization or controlled exchange, when authorized, may be used as a source of supply for
items with the above source codes, except for those source coded "XA" or those aircraft support items
restricted by requirements of AR 700-42.
3. Explanation of Columns (Sections II and III).
a. ITEM NO. (Column (1)). Indicates the number used to identify items called out in the illustration.
b. SMR CODE (Column (2)). The Source, Maintenance, and Recoverability (SMR) code is a 5-position
code containing supply/requisitioning information, maintenance category authorization criteria, and
disposition instruction, as shown in the following breakout:
Source
Maintenance
Recoverability
Code
Code
Code
Who determined
How you get an item
4th position
3d position
disposition
Who can install,
Who can do
action on an
complete repair*
replace or use
unserviceable
on the item
the item
item.
*Complete Repair: Maintenance capacity, capability, and authority to perform all corrective
maintenance tasks of the "Repair: function in a use/user environment in order to restore serviceability to a
failed item.
(1) Source Code. The source code tells you how to get an item needed for maintenance, repair, or
overhaul of an end item/equipment. Explanations of source codes follows:
2
