I thought there were many interesting instances of the motif of flying throughout Song of Solomon, especially because the novel starts out with a man claiming to all that he can fly. He even put up posters regarding the time and date of his flight. Then, at those specified times, he went up to the hospital roof waiting to fly, or jump off the roof. It wasn't considered suicide, and even the people on the ground were not preventing him from "flying". Instead, they were supporting and encouraging him. Therefore, his flight was seen as a escape from the endless cycle of the struggles in life and a journey onto a new chapter.
One of the most significant instances is at the end after Pilate was shot. Milkman sees Pilate as an exception. He says she could fly without even leaving the ground, which means she has mastered flight. Pilate led a life that involved fulfilling her own wishes; she was her own individual. This lifestyle led to her master of flight because even though she didn't expect to die, Pilate was able to accept her death and "fly away" satisfied with her life, leaving no burdens behind for anyone. Pilate was a special woman, and Milkman finally outwardly acknowledges her uniqueness at her death.