SV-51

The SV-51 was the only variable fighter developed by the Anti-U.N. forces. This top secret fighter was constructed in a collaboration between Sukhoi, IAI and Dornier with the use of alien overtechnology obtained illicitly from the U.N. variable fighter development under undisclosed circumstances.

Like the VF-0 Phoenix, the SV-51 is an advance trial production model equipped with conventional engines, developed before planned variable fighters with thermonuclear turbine engines, and cannot be used in space. However, despite being a prototype, this Anti-U.N. variable fighter was designed from the beginning for actual combat. While it too incorporated the three-mode transformation concept of the VF-0, this feature was treated as an add-on to the familiar design principles of a pure fighter jet and not as well-integrated as the system on board the variable fighters of the U.N. forces. Although the SV-51 in combat against the VF-0 displayed a higher level of practicality and stability in combat situations- its active stealth system achieved higher efficiency and output compared to the VF-0's system, and it had VTOL capabilities without needing to transform from Fighter to GERWALK mode- the additional equipment to make such a feat possible not only led to larger dimensions and mass but also contributed to its shorter cruising range than that of the VF-0 despite preserving very good air combat maneuverability, indeed a reminder of the Sukhoi design bureau's legacy. It also had relatively underpowered transforming actuators and therefore a slower transformation sequence than the Phoenix as a result. This became an important weakness, as transforming under enemy fire proved a rather common occurrence due to the fluidity of combat between variable fighters.