I flew on a lark, sang on a trill, crashed on a wing. What am I? I've tried to figure out this riddle posed in a comic book. There was no official answer, but it is visually suggested that it is comprised of only 2 letters (The context was a crossword death-trap, and the word in question was marked on the crossword by 2 green spaces). The best I can figure is LA, as in the musical note. To fly on could simply suggest that it is attached to lark, and those are the first two letters of the subject of that section, the lark. A trill is a vibratory sound, often musical in nature. These seem to make sense, except for the last part to "crash on a wing". I enjoy riddles, but I just can't handle not figuring out an answer. Help!
For copyright purposes: The riddle comes from All-Star Batman issue #7 by Scott Snyder and Francesco Francavilla. Property of DC Comics.