Stavatti Aerospace reveals the SM-39 Razor, a Mach 4 fighter boasting a unique triple-fuselage design for unparalleled speed and advanced stealth.
By Kris Osborn, Warrior
A private company called Stavatti Aerospace has unveiled a potential stealth jet Next-Generation Air Dominance 6th-gen offering capable of reaching speeds of Mach 4, a speed roughly twice as fast as the fast-emerging F-47 6th-gen aircraft. The new concept jet, called the SM-39 Razor, presents an unusual if not unprecedented triple-fuselage design intended to reduce drag for sustained high-speed flight.
The SM-39 Razor is a concept aircraft characterized as a next-generation air dominance fighter, interceptor, and all-weather strike aircraft, attributes explained in an interesting essay from Next-Gen Defense. Its design emphasizes extremely high speeds (Mach 4+), advanced materials, variable-cycle engines, and multiple configuration options (single-seat, two-seat, and autonomous variants). The company’s literature also highlights advanced avionics, active stealth features, and the integration of “Synthetic Intelligence” for autonomous operations.
SM-39 Razor Mach 4
The SM-39 Razor concept places tremendous emphasis on high-speed performance. It is designed to exceed Mach 4, potentially using variable cycle engines that balance cruise efficiency with supersonic thrust. Its titanium diboride cermet structure and advanced engine designs suggest a focus on pushing the boundaries of conventional fighter performance.
By contrast, the F/A-XX NGAD’s performance specifications remain largely undisclosed, though public analysis suggests that extended range and survivability are prioritized over raw speed. While anticipated to travel at speeds greater than Mach 2, the F/A-XX could bring an F-22-”plus” like capability to maritime, carrier-launched attack. When it comes to the F/A-XX, the Navy reportedly emphasizes a 25 % increase in range over existing tactical aircraft to operate from beyond the reach of advanced anti-ship weapons and to enable deeper strike and air superiority operations. This translates to a combat radius potentially exceeding 1,500 miles, although actual top speeds, thrust class, and propulsion technology remain classified.
SM-39 “Hypersonic Interceptor”
Comparatively, the Razor’s claimed capability to maintain level Mach 2.5+ cruise with bursts beyond Mach 4 positions it more like a hypersonic-inspired interceptor or rapid engagement platform. In contrast, F/A-XX appears optimized for operational endurance, range, stealth, and adaptability to naval constraints (e.g., folding wings, carrier launch/recovery), rather than unparalleled top speed.
In the F/A-XX NGAD, low observability and sensor fusion are expected to be core attributes. Public reporting and concept art highlight stealth shaping, advanced sensors, and networked warfare capabilities, enabling the aircraft to operate in environments dense with advanced air defenses. The F/A-XX is also projected to integrate with unmanned “loyal wingman” drones and AI-enhanced systems for broader battlefield situational awareness and survivability. While it appears the SM-39 does have an unmanned variant or option, it is not clear how successfully it could operate drones from the cockpit or advance the “manned-unmanned” teaming concept.
SM-39 & Stealth
The SM-39 Razor includes low observability afterburner design features and advanced airframe materials, but much of its presented design centers on performance and structural capability. While the platform has internal weapon bays and provisions for stealth-friendly modules, its high-speed aerodynamic surfaces and external hardpoints could increase radar signature compared to a purpose-built stealth aircraft like the F/A-XX. Additionally, the SM-39’s modular design suggests adaptability rather than innate stealth optimization. It may be that SM-39 designers anticipate relying upon pure “speed” as a stealth and survivability-enhancing characteristic, yet its smooth rounded contours and blended fuselage-wing-body configuration does appear stealthy. With three fuselage-type structures, one wonders if the SM-39 will span a wider surface area, making it easier for enemy radar to detect.
A defining emerging trend in combat aviation is manned-unmanned teaming (MUM-T). The F/A-XX NGAD is being designed not just as a standalone fighter, but as the “quarterback” of a larger network, directing and integrating with unmanned systems, electronic warfare assets, and extended sensor arrays across the battlespace. This reflects a vision of distributed combat power, where the aircraft’s role extends beyond traditional dogfighting to orchestrating networked engagements.
The SM-39 Razor concept also includes autonomous variants, with a dedicated SM-39U unmanned configuration and an AI-centric control system. This suggests it could operate with varying levels of autonomy, potentially in contested airspaces or as part of a larger mixed force. However, these autonomous features are conceptual and likely far from the integration expected in an NGAD family of systems.
Osborn previously served at the Pentagon as a highly qualified expert in the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University