Applying Best Practices to Military Commercial-Derivative Aircraft Engine Sustainment: Assessment of Using Parts Manufacturer Approval (PMA) Parts and Designated Engineering Representative (DER) Repairs

U.S. airlines have successfully used Parts Manufacturer Approval PMA parts and designated engineering representative DER repairs to decrease the cost of their aircraft engine maintenance. These parts and repairs are provided by third-party companies and are certified by the Federal Aviation Administration to be airworthy and interchangeable with original equipment manufacturer OEM parts or repairs. The U.S. Department of Defense DoD operates many commercial-derivative engines in its tanker, transport, and command and control and communications aircraft fleets. Many of those engines share common technologies, designs, and even parts with commercial engine variants. This report explores the potential for cost savings in DoD through the greater use of these commercial engine maintenance practices. Although some within DoD are familiar with PMA parts and DER repairs and associated practices and policy, most are not. This report includes background information required for those readers who are less familiar with them.