Ace Combat: Ikaros in the Sky

Ace Combat: Icarus in the Sky (エースコンバット イカロス・イン・ザ・スカイ) is a novel for Ace Combat franchise. Synopsis is largely unknown at the moment, but the story will involve Kei Nagase, ASF-X Shinden II, and a "mysterious man". It will be published on 28th March 2012.

Source
Project Nagase blog