Human beings have always been fascinated with flying as a symbol of freedom and a method of escape from sadness, pain or oppression. In Song of Solomon, Milkman embodies this desire which is made obvious from the book's opening; he is born on the very day that an man straps wings to his back and attempts to fly from the top of Mercy Hospital.
From that point on, Milkman is attempting to fly. He feels downtrodden in his unhappy home, stifled working for his father, stalked by his girlfriend and browbeaten by the political and racial obsessions of his friend Guitar.
When he has a chance to visit his ancestral home, he feels at peace and joyous in the airplane soaring above the clouds. He learns that his grandmother's family name was, ironically, Byrd, and that his great-grandfather had mysteriously "flown" back to Africa leaving his wife and children.
Milkman's last flight, however, is his death. Facing the anger of his friend Guitar, Milkman leaps from a cliff as a bullet penetrates his chest. He has finally "surrendered himself to the air."