Flight to me implies speed.... which does not describe the hobbits movements here. Also how does the mighty Ranger get turned around so that they go off course more than once?
I would say that the chapter title specifically refers to the final stretch with Frodo riding Glorfindel's horse. Tolkien had done his share of hiking (and marching, I expect) and must have known how easy it can be for even an experienced traveler to go astray when there is no clear path. "He who lies artistically, treads closer to the truth than ever he knows." -- Favorite proverb of the wizard Ningauble of the Seven Eyes