This is a very early serial that people still tend to talk about a lot. In my view it's famous mainly because the hero breaks out into a really dumb little song in the middle of an airplane in Chapter One, and again a couple of times later in the picture. "Ace Drummond" was a comic strip created by World War One flying ace Captain Eddie Rickenbacker.John King was better known for Westerns--he should have stuck to them. Jean Rogers, of course, was Dale Arden in the first two Flash Gordon serials, and also appeared in "Secret Agent X-9" (1937). Guy Bates Post, a great old character actor, is great as the Grand Lama. Lon Chaney, Jr. plays a small part as a henchman, which he often did in serials.