Trinity

An unknown superweapon has been confirmed to appear in the story of Ace Combat: Assault Horizon, under the control of the antagonistic East African militia. This weapon is mentioned in the story section of the official Assault Horizon site, and the information is as follows:

"Shortly after arriving in Africa, a helicopter force on a guerilla sweeping mission is engulfed in a blinding flash of light, and blasted out of the sky by a massive shock wave. The few helicopter crews who survive the blast are brought back to the base covered in third-degree burns. Word quickly spreads that the anti-government insurgency has developed a new type of super weapon. Before the task force has time to investigate how the insurgency succeeded in developing such advanced weaponry, the scramble alert sounds. As Bishop and company race to secure the super weapon, the flames of battle spread across northern Africa, eventually engulfing the world."

- Paragraph describing the superweapon

The above paragraph says how the helicopter crewmen were "blinded by a flash of light", and "blasted out of the sky by a massive shockwave", as well as mentioning how the survivors of the incident were "returned to base in third-degree burns". Taking these two facts into account, the text infers that the superweapon in question is most likely a thermobaric weapon.