USAF

The U.S. Air Force says it estimates a fleet of Next Generation Airlift (NGAL) aircraft will be flying operational missions by the 2040-2041 timeframe. The service hopes to have its C-5M Galaxy and C-17A Globemaster III cargo planes replaced by NGAL types by the mid-2040s and mid-2070s, respectively. By 2075, the C-17, a type that has been under particular strain in recent years, will have been in service for 80 years, though the remaining individual aircraft will be younger than that.

Air Mobility Command (AMC) laid out its latest vision for its future airlift fleets in a strategy memo released earlier this week. The document reconfirms that the current plan is for a single NGAL aircraft to supplant the C-5M and C17A, which AMC had first disclosed publicly in September. At that time, the command had only said it was targeting the mid-2040s timeframe to begin making the transition to its new cargo planes. The Air Force had 222 C-17As and 52 C-5Ms in its inventory as of the start of Fiscal Year 2025.

“With an accelerated NGAL Analysis of Alternatives (AoA) in FY27 [Fiscal Year 2027] and an uninterrupted acquisition process with consistent funding, the first NGAL aircraft could be produced as early as FY38,” the Airlift Recapitalization Strategy document, dated November 18, 2025, explains. “It is estimated [that] the NGAL program will reach Initial Operational Capability (IOC) in FY41.”

U.S. government fiscal years run from October 1 of the year before through September 30 of the year in question. So, for example, Fiscal Year 2041 starts on October 1, 2040, and ends on September 30, 2041.

“One NGAL aircraft will replace one C-5M aircraft until the entire C-5M fleet is retired. Then, the C-17A fleet will be replaced by NGAL at a one-for-one swap,” the document adds. “Uninterrupted inter-theater airlift capacity is paramount for global operations during fleet recapitalization. Current recapitalization projections require C-5M viability until 2045 and C-17A viability through 2075.”

The Air Force’s C-5Ms were all upgraded from older B and C variants that began their service careers in the 1980s. C-17As first began entering operational service in 1995. Neither of these aircraft is still in production.

By 2045, the youngest C-5Ms will have been flying for some 56 years. As already mentioned, the Air Force is now set to keep flying C-17s for eight decades. The service took delivery of its last Globemaster III in 2013, which will be 62 years old in 2075.

It’s also important to point out here that a succession of major crises globally has led to persistently high demand for the C-17 fleet in recent years. The aircraft have played notably critical roles in the chaotic U.S. withdrawal from Afghanistan in 2021, the delivery of military aid to Ukraine immediately before and since Russia’s all-out invasion in 2022, and various contingencies around the Middle East since 2023. This, in turn, has put immense strain on the aircraft, and their crews, and has created additional sustainment challenges. With all this in mind, how exactly the Air Force concluded it would be feasible to keep the C-17s flying through 2075 is unclear.

“To mitigate risks associated with acquisition delays, funding uncertainties, or technological challenges, the existing C-5M and C-17A fleets’ operational viability must be maintained until a fully capable replacement is fielded, which may require extending the service life and associated Military Type Certificate (MTC) of each platform,” the AMC airlift strategy document does note.

There have been growing discussions already about re-engining the C-17 fleet, which could help extend the operational life of those aircraft. New engines that offer greater fuel economy and/or higher reliability could give the aircraft a boost in performance, as well as reduce operating costs and sustainment demands.

“The C-17 and C-5 … served us well for decades, but they’re not going to fly forever, and so we’d like to recapitalize those on our timeline,” Air Force Gen. John Lamontagne, head of AMC, had told TWZ and other outlets at a roundtable on the sidelines of the Air & Space Forces Association’s 2025 Air, Space, and Cyber Conference in Spetember. “We’d like to have a plan in place so when the service life starts to erode on the C-17, whether it’s wings, engines, or more, we’ve got a competition already going.”

AMC does also have plans now for other capability upgrades to its existing airlift fleets, especially the workhorse C-17s, to ensure their continued relevance, especially in future high-end fights. The Globemaster IIIs are already in the process of getting new beyond-line-of-sight communications suites, and new defensive systems could also be on the horizon.

Many questions about the successor NGAL aircraft still remain to be answered, as well, including whether or not the Air Force might require the design to incorporate stealthy features. Vertical takeoff and landing capabilities and other ways to reduce dependence on traditional runways, access to which is expected to be greatly limited in future major conflicts, might also be part of the equation. The Air Force has explored advanced airlift and aerial refueling tanker concepts that include these elements on multiple occasions in the past. TWZ has been calling attention to the growing need for more survivable cargo planes and tankers for years now.

“As far as what we want in the next[-generation airlift] platform, we want agility, we want speed, we want to be able to operate in a higher threat environment,” Gen. Lamontagne had said in September. This includes “countermeasures that are effective against those threats that are coming from increasingly longer ranges.”

On top of all this is the key equation of how the Air Force expects to replace the C-5M and C-17A with a single platform. The Galaxy and Globemaster III are very different size-wise, as well as in the kinds of missions they were designed to perform, as TWZ has highlighted in the past.

At least one company, Radia, is openly pitching a new airlifter to the Air Force that is bigger than the C-17 and the C-5. However, the Windrunner design is also still in a very aspirational phase of development, as you can read more about here.

Lockheed Martin and Boeing, among others, have also been publicly showing various concepts for advanced transports and tankers in recent years.

The Air Force has talked previously about the potential for NGAL to be a ‘system of systems’ rather than a single aircraft. Speaking in September, Gen. Lamontagne said it remained possible that multiple aircraft types could ultimately come under the NGAL umbrella, but raised concerns about whether his service “can afford, grandkids, kids, all of them.”

No matter what aircraft the Air Force ultimately acquires under NGAL, the service has now set a clear goal for them to begin entering operational service within the next 15 years or so.

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