Forum:Why dose Pertricco want the feathers?

In the beginning of Assassin's Creed II, Pertcricco asks Ezio if he can get the four feathers Ezio asks "Why?" and Pertricco said "I will tell you, in good time". Now I have heard rumors that he needed them to help Leonardo Da Vinci with the Flying Machine, others say they where just to make a replica of the Eagle as he knew Giovanni was an Assassin, Any rumors?