- The U.S. Navy’s MQ-25 Stingray program missed its planned Milestone C decision after production delays and supplier quality issues disrupted the original test and acquisition schedule.
- DOT&E said available assessment data were inadequate for Milestone C because they came from a prototype that differed from the production-representative aircraft, fuel system, communications, and ground control architecture.
The United States Navy’s MQ-25 Stingray carrier-based unmanned tanker program missed its originally scheduled Milestone C decision after production delays, test-asset delays, and concerns that the available data were not suitable to support the move into the next acquisition phase, according to the Pentagon’s Director, Operational Test and Evaluation annual report.
The report states that the Milestone C decision had been scheduled for fiscal year 2023 under the program’s 2020 test plan, but “MS C did not occur in FY23.”
The delay matters because the MQ-25 Stingray is intended to become the Navy’s first operational carrier-based, fixed-wing unmanned aircraft launched by catapult, with a mission centered on aerial refueling and intelligence, surveillance, and reconnaissance support for the carrier strike group.
According to the report, the Navy revised its Milestone C approach in December 2022 after what DOT&E described as “production delays and sub-vendor quality control issues.” Instead of relying on the operational assessment framework originally outlined in the 2020 Milestone B Test and Evaluation Master Plan, the service moved toward using an early operational assessment based on data collected between June 2019 and December 2021 from a Boeing-owned, Boeing-operated, and Boeing-funded MQ-25 prototype. DOT&E concluded that approach was inadequate for a Milestone C decision.
As laid out in the annual report, the central issue was not simply that data existed, but that the data did not come from production-representative hardware and systems. DOT&E said there were “significant differences” between the prototype and the MQ-25A Engineering Development Model design, including internal structures, fuel system design, communications, and network architecture. The report also states that the prototype flew with a Boeing ground station rather than the Lockheed Martin-produced Unmanned Mission Control System ground station planned for fleet aircraft.
That distinction is critical in acquisition testing. A prototype can demonstrate that an idea is technically possible, but Milestone C is meant to support a decision to enter production. For that step, test authorities generally need data from aircraft, mission systems, and support equipment that closely match the configuration that operators will actually field. In the MQ-25 case, DOT&E said the prototype testing was never originally intended to inform an early operational assessment, and DOT&E did not observe that testing.
The report further states that an extension of the engineering and manufacturing development phase, combined with delays in producing test air vehicles, pushed the program off its earlier schedule. The Navy received its first MQ-25 Engineering Development Model air test vehicle in May 2025 and expects the first flight test event with that aircraft in the first quarter of fiscal year 2026.
Boeing said on January 29, 2026, that the first operational MQ-25A Stingray had successfully completed its first taxi test. The company said that, at the push of a button from Air Vehicle Pilots in the Unmanned Carrier Aviation Mission Control System, the aircraft autonomously taxied from the new MQ-25 production facility in Mascoutah, Illinois, to the taxiway at MidAmerica St. Louis Airport and carried out a series of maneuvers to validate functionality. Boeing said the milestone moved the United States Navy’s first MQ-25A closer to its first flight.
As noted in the annual report, the program office prepared an updated Milestone B TEMP during fiscal year 2025 to better scope and resource integrated test events. The Navy rejected that update and instead directed the creation of a Milestone C TEMP to support a Milestone C decision then planned for the fourth quarter of fiscal year 2025. Even so, DOT&E stated that “insufficient data existed to inform a MS C decision” because the Navy had not completed an adequate early operational assessment or operational assessment using production-representative air vehicles and a production-representative ground station.
The report shows that the testing path is still being rebuilt around more representative conditions. DOT&E has not approved any operational test plans for MQ-25 so far, and it said the Navy should submit a plan that includes an adequate operational assessment. The report also says that this assessment should use non-prototype air vehicles and include the MQ-25’s primary operational environment, meaning carrier-based flight operations, through the first aircraft carrier flight test period.
The MQ-25 is designed to solve a practical carrier air wing problem. Carrier-based fighters are often required to serve as organic tankers, which reduces the number of aircraft available for strike and air defense tasks. A dedicated unmanned tanker would return that mission set to a platform built for it, while also introducing a new level of organic unmanned aviation into deck operations. The Navy’s stated mission for MQ-25 is to provide tanking and ISR capabilities to the carrier strike group, extend carrier air wing strike range, and help close a persistent sea-based ISR gap.