US military spends $178M to keep aging J85 jet engine in service

The U.S. military has been quietly spending over $178 million on J85 jet engine supplies across a series of contracts and modifications.

General Electric Co., operating from its Lynn, Massachusetts facility, has received a sequence of awards against delivery order SPE4AX-25-F-1356, itself issued under a five-year six-month base contract with a four-year six-month option period.

The original delivery order, worth an estimated $107,792,833 and awarded on December 20, 2024, established the framework for J85 engine supplies under Performance Period 5. What followed was a series of monthly and multi-month lot payment modifications that have incrementally added tens of millions of dollars to keep the production and delivery pipeline running: a $9,799,348 modification in March 2025 for December 2025 lots, another $9,799,348 modification in December 2025 for January 2026 lots, a $30,666,625 modification in January 2026 covering February through April 2026 lots, and a $20,444,417 modification in April 2026 covering May and June 2026 lots. The contracting activity across all of these awards is Defense Logistics Agency Weapons Support in Richmond, Virginia, with both Air Force and Navy listed as using military services.

The J85 is a small, lightweight turbojet engine that GE first developed in the late 1950s, and its longevity in U.S. military service is one of the more remarkable stories in American aviation propulsion history. The engine powers the T-38 Talon — the supersonic jet trainer that has been producing Air Force pilots since 1961 and remains the primary advanced jet trainer for USAF pilot production today. It also powers the F-5 family of fighters, which the Navy operates as adversary aircraft at its aggressor squadrons and which multiple allied nations continue to fly in frontline service. The combination of those two major roles — pilot training and adversary simulation — means the J85 is not a peripheral legacy system being kept alive through institutional inertia. It is actively essential to how the United States produces fighter pilots and trains them against realistic threat replication.

The T-38 connection is particularly significant. The Air Force trains every pilot who will eventually fly an F-22, F-35, B-2, or any other advanced aircraft through a syllabus that includes T-38 time. The T-38 fleet is aging — the airframes are old, and the engines that power them are the same J85s that have been in production and service for generations — but replacing the T-38 has proven complicated enough that the Air Force has kept investing in T-38 sustainment while the T-7A Red Hawk, the aircraft intended to replace it, works through its own development challenges. Every modification to the J85 delivery order is, in part, a decision to keep the T-38 pipeline running for another month, another quarter, another year.

The adversary mission adds a different dimension. The Navy’s aggressor squadrons at Topgun and other adversary training programs use F-5s and other platforms to replicate the performance and tactics of adversary aircraft that American pilots might face in combat. The F-5’s performance envelope, while not cutting-edge, is sufficient for the training role, and its J85 engines give it the thrust-to-weight characteristics that make it a credible training opponent. Keeping J85 supplies flowing ensures that adversary training can continue at the pace the Navy needs to keep its fighter pilots tactically current.

The sole-source acquisition justification for the original delivery order — 10 U.S. Code 3204(a)(1), which permits noncompetitive contracting when only one responsible source exists — reflects the reality of J85 production. GE designed the engine, holds the technical data, maintains the production tooling, and is the only entity capable of manufacturing J85 engines and components to the military’s airworthiness standards. For a propulsion system with this kind of history and installed base, maintaining a sole supplier is not a procurement shortcut — it is the straightforward consequence of how specialized military aviation propulsion technology is developed and sustained.