FF(X)

This article is about the U.S. Navy program. For similarly named topics, see FFX (disambiguation).

Not to be confused with FFG(X).

Rendering of the FF(X) frigate, based on the Legend-class cutter
Class overview
Builders	Huntington Ingalls Industries
Operators	United States Navy (projected)
Preceded by	Constellation class
General characteristics
Type	Frigate
Armament	Flight I 1 × BAE Systems Mk 110 57 mm gun 2 × 30 mm guns 1 × 21-cell Mk 49 RIM-116 Rolling Airframe Missile launcher Up to 16 × Naval Strike Missile launchers

FF(X) is the designation for a class of frigates intended for the United States Navy based on the National Security Cutter (NSC) or Legend-class cutter in service with the United States Coast Guard. The program was announced on December 19, 2025, and the ships will be built by Huntington Ingalls Industries. ^[1]

Development

The Legend-class cutter, the base design for the FF(X)

On November 25, 2025, Secretary of the Navy John C. Phelan announced the cancellation of the Constellation-class frigate program beyond the first two hulls, citing the need to build ships at a faster rate. ^[2]

The FF(X) program was announced on December 19, 2025, in social media posts by Phelan and Chief of Naval Operations Admiral Daryl Caudle. ^[1] The program's objective is to have the first ship in the water by 2028. ^[3]

Design

Changes from the original NSC design include the construction of a platform above the stern boat deck for modular containerized payloads and unmanned systems. ^[3] In the FF(X) renderings, a "shelf" was added to the bottom front end of the superstructure, presumably a space for future upgrades such as vertical launching systems (VLS), laser-based directed energy weapons or some other close-in weapon system s. ^[4]

The initial flight of the class will be equipped with a Mk 110 57 mm gun, two 30 mm guns, a Mk 49 launcher for 21 RIM-116 Rolling Airframe Missiles for point defense and up to 16 RGM-184A NSM anti-ship missiles, but it will not feature an integrated VLS. ^[5] Flight I ships will also lack anti-submarine warfare (ASW) equipment, though this capability may be added in the future. ^[1]

The FF(X) is similar to HI Industries' 2012 "Patrol Frigate" proposal, also based on the Legend-class hull, previously offered to the U.S. Navy as a replacement for the Littoral Combat Ship. ^[4] However, there are notable differences between the respective conceptual renderings, including variations in the size of the main superstructure and the gun turret. ^[4] Notably, the Patrol Frigate design incorporated a 12-cell Mk 56 VLS unit, a capability not included on Flight I ships of the FF(X). The Patrol Frigate concept also included an expanded sensor suite. ^[4]

References

1. LaGrone, Sam (December 19, 2025). "SECNAV: New Frigate will be Based on National Security Cutter, First FF(X) to be Built at Ingalls". USNI News. Retrieved December 19, 2025.
2. LaGrone, Sam (November 15, 2025). "Navy Cancels Constellation-class Frigate Program". USNI News. Retrieved December 19, 2025.
3. "Navy Announces New Small Surface Combatant". U.S. Navy. December 19, 2025. Retrieved December 19, 2025.
4. Trevithick, Joseph (December 19, 2025). "This Will Be The Navy's New FF(X) Frigate". The War Zone. Retrieved December 29, 2025.
5. Trevithick, Joseph (December 22, 2025). "Navy's New Frigate Will Not Have A Vertical Launch System For Missiles". The War Zone. Retrieved December 22, 2025.