A recent Government Accountability Office (GAO) report found that while the Navy’s new frigate class is using many systems proven on other ships, the propulsion and machinery control systems have not been fielded or tested before and present high risk.
Given that the first ship in the new class, the future USS Constellation
(FFG-62), is running three years late, GAO argued this “could offer the program the chance to do land-based testing of these two unproven systems.”
FFG-62 was planned to be delivered in April 2026, but it is now running about 36 months late due to problems with finishing the design and shipyard workforce challenges.
The GAO report, “Navy Frigate: Unstable Design Has Stalled Construction and Compromised Delivery Schedules,” said the Navy’s frigate program acquisition strategy requires all integrated systems to have achieved maturity by relying on technology that at least has a representative model or prototype demonstrated in a relevant, but not fully realistic, environment.
It argued the Navy’s measure of technology maturity for this is “inconsistent with our technology readiness best practices, which established that technologies are mature once the technology is demonstrated in a realistic environment.”
The report underscored while the Navy program reports it has no new or novel technologies GAO’’s analysis found several systems pose various levels of risk, including high risk in propulsion and machinery control systems.
It assessed the combined diesel-electric and gas turbine propulsion system as high risk because the Navy has not previously used it while also experiencing challenges and at-sea failures in certain propulsion systems.
This will include a combined diesel-electric and gas turbine, two electric propulsion motors, a reduction gear, and two fixed pitch propellors. While this architecture is similar to that of the original Italian FREMM parent design, the office highlighted FFG-62’s propulsion system required design changes to meet Navy requirements and standards.
While the gas turbine is the same, the U.S. Navy version of the electric propulsion motor will be more powerful, the ship service diesel generator will be more powerful, the main reduction gear is newly designed to meet Navy requirements and it will include newly designed fixed pitch propellors designed to increase ruggedness and reliability.
“This increased cost and introduced integration risks, according to shipbuilder representatives. As a result, the Navy redesigned components to be different from the Italian frigate propulsion system,” the report said.
The current test plans for the propulsion system do not plan for land-based testing until after FFG-62 is delivered. “This increases the likelihood of discovering deficiencies while the ship is at sea, which could limit fleet availability,” GAO added.
GAO also found high risk with the machinery centralized control system, which it underscored has consistently posed challenges to new ships in recent years.
This is the user and control interface for 45 subsystems on the frigate, like alarms, water systems and propulsion. Control system developer L3Harris Technologies [LHX] told GAO they are using open-source tools rather than proprietary software solutions used in previous ship classes to reduce technical risk from obsolescence.
While GAO approvingly noted open-source software can save costs and increase efficiency, this system faces risks from new software code and limitations in developer simulation testing.
“For example, L3Harris representatives explained that the frigate’s control system is made of roughly 95 percent new software code due to major changes from the parent ship design and integration with new equipment and systems. These representatives also stated that the builder of the control system used in the parent design used proprietary tools. This prevented L3Harris from using its developmental tools when developing its control system for the frigate,” the report said.
Navy officials also told GAO the biggest risk is integrating propulsion system components with this control system and the integrated power systems.
GAO argued while the Navy’s land-based engineering site (LBES) for the frigate is not expected to be fully online and ready for testing before December 2026, the delays to the frigate “opens the door to revisiting the Navy’s plans for how and when it uses LBES to test frigate propulsion and control systems.”
“This delay provides the Navy an opportunity to identify a path forward that uses LBES for proactive, discovery focused testing of the propulsion and control systems—with an eye toward identifying and resolving deficiencies in a less jeopardizing environment than after a problem has occurred aboard the lead ship at sea,” it continued.
GAO also labeled three systems as medium risk and two as low to medium risk.
The AN/SPY-6(V)3 air and missile defense radar, Aegis Weapons System Baseline 10.F and Combined Active Passive Towed Array Sonar (CAPTAS-4C) are medium risk. GAO said the first two are meant to include lessons learned from installing and testing those or similar systems on other ships, but much of that work is not expected to be done before FFG-62 delivers, opening the systems to more risk as they are installed on the frigate. Moreover, some of the radar testing will be done on the original and different variant of the SPY-6 radar with the Arleigh Burke-class Flight III destroyer USS Jack H. Lucas (DG-125).
Separately, CAPTAS-4C has been fielded on foreign navy ships but never integrated with the U.S. Navy or with the AN/SQQ-89(V)16 undersea warfare/anti-submarine warfare combat system.
The Mk 41 Vertical Launch System and AN/SLQ-32(V)6 Electronic Warfare System are marked as low to medium risk because they have been fielded on various ship classes, but will require new software for integration on the frigate.
One of the GAO’s recommendations specifically suggested while the Navy revises the frigate’s test and evaluation master plan (TEMP) in 2025 it should ensure the plan incorporates additional land-based testing activities for the propulsion system and machinery centralized control system and schedules those activities on a timeline that realistically accounts for anticipated lead ship delivery delays.
While the Navy partially agreed with this, it said it does not intend to update the TEMP to include these additional test objectives because it views the LBES primarily as a tool for sustainment. The Navy said it will leverage early opportunities for additional risk reduction efforts as the LBES facility becomes available for use.
The Navy estimates the LBES will be finished by fiscal year 2029.