C-5

The C-5 Modification Program is a line item in the Air Force's FY 2026 budget request under Aircraft Procurement, specifically focused on the modification of in-service airlift aircraft. The overarching goal of this program is to sustain and enhance the operational capability of the C-5M fleet, which is essential for strategic airlift missions.

The C-5M Galaxy is a critical asset, capable of transporting outsized and heavy cargo, such as tanks and helicopters, as well as personnel and standard cargo pallets. With 52 aircraft delivered between 1969 and 1989, the Air Force seeks to extend the service life of these aircraft to at least 2040 through targeted reliability enhancements and modernization efforts.

The program's objectives are centered on procurement and installation of several key modifications. One major focus is addressing Diminishing Manufacturing Sources (DMS) and obsolescence issues that threaten fleet readiness. Activities supporting these objectives include studies, analyses, life-of-type buys, risk reduction, engineering change orders, and program support. These efforts ensure the C-5M remains mission-capable and compliant with evolving operational and audit requirements, including those mandated by the FY 2008 National Defense Authorization Act and Title 10 U.S.C. Chapter 9A, Sec 240-D.

Embedded Diagnostic System II (EDS II) is a new start initiative in FY 2026. The EDS II modification replaces the obsolete auxiliary maintenance computer, Personal Computer Interface Unit, and key loading panel with a modern computing architecture. This upgrade simplifies the system design, enables ethernet loading of mission software, and supports backup radio cryptographic key loading. EDS II is projected to reduce non-mission capable rates and is essential to prevent aircraft groundings beginning in FY 2029. Development and prototype testing are being supported by Weapon System Sustainment (WSS) engineering funds due to the urgency of DMS and obsolescence concerns.

Mission Systems Equipment-Lavatory (MSE-Lav) is another modification aimed at improving crew comfort and operational capability. The FY 2026 budget allocates funds for the procurement and installation of upgraded lavatory systems, addressing reliability and maintainability issues identified in the legacy fleet. This effort supports both active and reserve components, ensuring consistent capability across the entire C-5M fleet.

Low Cost Modifications are included to provide incremental capability improvements and address emergent needs. These modifications are funded to enable rapid response to operational requirements and to implement minor upgrades that collectively enhance fleet performance. Examples include minor avionics updates, software improvements, and other reliability enhancements that do not require major redesigns.

Additional line items within the C-5 modification program include Communication Navigation Surveillance/Air Traffic Management (CNS/ATM) upgrades, Mission Computer and Weather Radar enhancements, and Training Systems (Training Mods). The CNS/ATM upgrades ensure compliance with evolving airspace requirements and improve global mission effectiveness. Mission Computer and Weather Radar modifications enhance situational awareness and operational safety, while Training Mods support the development and sustainment of aircrew proficiency.