C-37A

The C-37A Modification Program is a line item within the Air Force's Aircraft Procurement budget, specifically under the Modification of Inservice Aircraft activity for Airlift Aircraft. The primary goal of this program is to fund essential modifications to nine C-37A and seven C-37B aircraft, which are military equivalents of the commercial Gulfstream V and Gulfstream 550 platforms. These aircraft serve a critical role in transporting high-ranking United States government officials globally, necessitating a high standard of reliability, safety, and operational capability.

One of the key objectives of the C-37A/B modification program is to ensure continued Federal Aviation Administration (FAA) certification. This is achieved through the implementation of service bulletins and low-cost modifications that address regulatory requirements and enhance flight safety. As the fleet approaches its designed service life of 40,000 hours, with substantial hours remaining on both C-37A and C-37B aircraft, ongoing evaluations and updates are required to maintain airworthiness and operational readiness.

The program also aims to improve reliability and maintainability of the C-37 fleet. Modifications funded under this line item may include upgrades to avionics, communications systems, and other mission-critical equipment. A significant focus is placed on the modernization of the Senior Leader Communications System, which ensures secure and effective communication capabilities for government officials during transport. These efforts are vital for supporting the unique mission profile of the C-37 aircraft.

Another important objective is to address Diminishing Manufacturing Sources (DMS) issues. As certain components and systems become obsolete or unavailable, the program allocates resources to identify and implement suitable replacements or upgrades. This proactive approach helps mitigate risks associated with aging aircraft and ensures the long-term sustainability of the fleet.

Funding may also support Program Support Costs (PSC), Advisory & Assistance Services (A&AS), systems integration labs, trainers, and other government costs associated with maintaining and upgrading the aircraft. For FY 2026, no funding is requested under this line item, as efforts have been transferred to the OSAEA0, OSA-EA Modifications budget line to consolidate resources and increase funding flexibility. This transfer reflects a strategic decision to streamline budget management and better support evolving program requirements.