User blog comment:Kogath/Monster Hunter XX Discussion/@comment-25275196-20161028060429/@comment-27465049-20161028064932

Since the new area seems Ancient-ish and has a big mountain on it, and Jet Eagle is fought at high altitudes, the place to fight it is most likely the summit of the mountain in the new area. Kinda like how you fight Amatsu at the summit of Misty Peaks.