U.S. Air Force Extends C-5M Galaxy Service Life to 2050

The U.S. Air Force does not expect the last of its C-5M Galaxy cargo planes to be replaced until fiscal year 2050. This timeline is roughly five years later than the retirement schedule the service laid out last year. The Next-Generation Airlift platform, known as NGAL, is also expected to replace the C-17A Globemaster III fleet, which is projected to remain in service through 2075.

The C-5M is the largest airlifter in U.S. military service and provides unique capabilities. It can accommodate larger payloads by mass and volume than the C-17A and allows simultaneous loading and unloading from both nose and tail doors. The aircraft is used for moving outsized and unusual payloads by air, including satellites and other space-related items.

The service currently operates 52 C-5Ms, all converted from older B and C variants. The last of those legacy aircraft were built in 1989. Under the new timeline, the youngest C-5Ms will be 61 years old at retirement. The Air Force has 222 C-17As, with the last acquired in 2013.

Neither aircraft remains in production.

The Air Force recently disclosed that the C-5 fleet's mission capable rate has fallen to 37 percent. At a House Appropriations Committee hearing in April, Air Force Chief of Staff Gen. Kenneth S. Wilsbach stated the figure. Retired Air Force Gen. Michael “Mini” Minihan referenced earlier congressional testimony from U.S. Transportation Command commander Gen.

Randall Reed that had placed the mission reliability rate at 46 percent. The C-5 has a long history of maintenance challenges despite major upgrades. Lt. Gen. Rebecca Sonkiss, Deputy Commander of Air Mobility Command, addressed the sustainability questions in February.

She stated that the service has shown it can sustain older aircraft and that the C-5 performs when required, while noting the desire to move toward a modernized fleet.

The Air Force's fiscal year 2027 budget request includes $8.9 million for NGAL analysis of alternatives and concept development work under the C-5 Modernization Efforts funding line. This follows $200,000 provided earlier for the same effort. The analysis of alternatives process will assess options, refine requirements, and prepare for Milestone A approval and entry into the technology maturation and risk reduction phase.

A strategic airlift strategy document released last year had projected C-5M replacement by the mid-2040s. With an accelerated analysis of alternatives beginning in fiscal year 2027 and consistent funding, the first NGAL aircraft could be produced as early as fiscal year 2038.

Initial operational capability would follow in fiscal year 2041. The plan calls for one NGAL aircraft to replace each C-5M until that fleet is retired. The C-17A fleet would then be replaced on a one-for-one basis. The strategy document stressed that uninterrupted inter-theater airlift capacity must be maintained during the recapitalization period.

Lt. Gen. Sonkiss told reporters in February that work on NGAL is progressing to determine requirements for the next strategic airlifter that combines attributes of both the C-5 and C-17 fleets. The C-5Ms have been heavily used in recent years, including support for operations and buildup related to Iran and other Middle East contingencies.