Unless otherwise specified by contract, part substitution for parts identified in the current approved configuration documentation of an item from the product baseline through the remainder of the item's life cycle shall conform as follows:
a. Substitution of a non-repairable part for an item for which the contractor has configuration documentation custody shall not require a Class I or Class II engineering change or a request for deviation or waiver when:
(1) The part is identified as an authorized substitute or superseding part in a military specification or standard; and
(2) The part will not be installed in equipment to be submitted for verification and reliability demonstration tests.
b. Substitution of a non-repairable part shall require a Class II engineering change when:
(1) The part substituted is determined, by the contractor having configuration documentation custody over the item, to be a preferred part over the original; or
(2) The contractor does not have configuration documentation custody.
c. Part substitutions which do not meet the requirements of 5.4.5a or 5.4.5b and for which a permanent change is not desired shall require submission of a Request for Deviation (RFD) or Request for Waiver (RFW).
d. All other parts substitutions shall be subject to the Class I or Class II engineering change as applicable.