According to Gen. Norton Schwartz, Air Force Chief of Staff, the service has not closed the door on providing new engines as well as avionics upgrades to its oldest C-5 airlifters, the A models. Currently, the service has planned only to employ full modernization—the so-called RERP for reliability enhancement and reengining program—for 49 C-5B models and two C-5C models. It has fully modernized one C-5A model and two C-5Bs for the RERP test program; those three aircraft are now C-5M models. Lockheed Martin began work on the first production RERP aircraft last summer and this month received low-rate-initial-production funding.
The Pentagon awarded a contract worth over $2 billion for the next batch of F-35 engines to Pratt & Whitney on June 5. The deal for Lot 17 F135 engines, totaling $2.02 billion, is expected to be completed by December 2025.