This is a commercial item procurement for the P8 aircraft. The contract includes an addendum requiring the contractor to notify the government of all proposed engineering changes and obtain written authorization before any change affecting form, fit, function, safety, or FAA certification. The contractor must provide affected part numbers and a required approval date, and make available commercial change documentation. All contractual documents are considered issued when sent via mail, fax, or email, with government acceptance of the proposal constituting a bilateral agreement. Early and incremental deliveries are accepted.