You can get "Spellbook – Aurabird Falcon" or "Spellbook – Aurabird Owl" by completing the quest Good Day to Fly, taken from NPC Engineer Lekon on Keucereus Alliance Base.
Spellbooks for learning Aurabird Falcon spellbook, Aurabird Owl spellbook and Final Flying Form can also be bought from NPC Officer Tolonis on Keucereus Alliance Base.
Transformation skills into Aurabird can be used only on the Gracia continent.
Transformation into Aurabird and Flying Final Form is possible in the following locations: all Keucereus Alliance Base locations, the Seed of Destruction/Seed of Infinity landing pads and the Aerial Cleft. combat zone
While transformed into Aurabird, you can't use existing consumables (potions, buff items, etc.).
Pets and summons can be summoned while transformed. However, this rule doesn't apply to flying transformations (i.e. Aurabirds or Flying Final Form).