[denethorthefirst]

Well, the Numenoreans are supposed to have Airships and Rockets (HOME 9) and a lot of the Silmarillion actually feels a bit like Science-Fiction when you read between the lines ... the decline in Arda is also technological, the Third Age is medieval and primitive compared to the First and Second Age. But that was not what i meant when i wrote that the "flying apparatus" would "fit" Arda. I meant that this interpretation believably explains how Luthien can "transform" (as you put it) herself and fly even though she does not possess the ability to change her hröa. Luthien is an elven woman and Elves are (like the Dwarves, the Humans, the Orcs, etc.) Incarnates that are bound to their body/hröa and are not able to change them. We may mock the tendency of the Fandom to invent and establish "rules" but that is one of the few hard laws of Ea, established by Tolkien himself in his writings. But: the "rules" can be handwaived away in this particular instance, because the whole Luthien-Beren-tale is (like the rest of the Silmarillion) mythological in nature, embellished and expanded upon by later generations. Over the centuries the tale grew with every generation until Luthien took Thuringwethils fur and actually flew away. Its not meant to be taken altogether literal. The Silmarillion is supposed to be the mythology of Middle-Earth and not an historical account.