Over the years, there have been quite a few pieces of Lord of the Rings trivia or lore that have become infamous within the fandom, as well as outside of it with the general population. There are memes that are widely shared (such as the classic "One does not simply walk into Mordor" one), as well as trivia that basically becomes an inside joke for fans as they're watching (such as the fact that Viggo Mortenson broke his toe while filming one scene and that specific take made the final cut, which is a fact that fans love to regale their less-knowledgeable friends with). These memes and questions often end up becoming just as iconic as the main events of the story itself.
One such question is one that is often posed by those who are casual watchers when they encounter the story of The Lord of the Rings for the first time. The question is, "Why didn't the Eagles simply fly Frodo to Mordor?" Certainly, on the surface it seems like this would have been a much easier solution for everyone involved. However, the actual answer to that question is a bit more complicated, and it turns out it would not have been such a simple solution after all.
What Are The Eagles?
The Great Eagles were messengers for Manwë, one of the Valar. They were giant birds that were capable of speech, and were initially sent to Middle-earth to keep an eye on the exiled Noldor and on their foe Morgoth. In the Third Age, which is the time period The Lord of the Rings takes place during, there was a colony of Eagles living in the Misty Mountains, and they would often keep tabs on the Goblins from that vantage point, as they were near Goblin-town. During the events of The Hobbit, they rescue Thorin and company from the Orcs and carry them to safety, and they also participated in The Battle of the Five Armies. Later, in LOTR, they appeared at the final battle at the Black Gates of Mordor and helped defeat the Nazgûl. They also rescued Frodo and Sam from Mount Doom after the Ring had been destroyed.
Why Couldn't The Eagles Take The Ring To Mordor?
This question that is commonly asked isn't exactly a huge leap in logic - after all, the Eagles will show up when all hope seems lost and will rescue the heroes at the last minute, saving the day. What's to prevent them from skipping all of that trouble in the first place and just take the Fellowship straight to Mordor? Well, the obvious answer is that there wouldn't be a story if Tolkien had chosen for them to take the easy way out like that. The journey is what makes The Lord of the Rings interesting, and none of that would exist if it was that simple for the Ring to be taken to Mordor.
The more complicated answer, and the one that serves more of an in-world purpose, is that while the Eagles often show up to assist, they're not a taxi service. They're great beings of Middle-earth, and they aren't there just to do people's chores for them. They make the choice of whether or not their assistance is needed, and they're not under anyone's orders. This means that they help when they see fit, no more, no less. They are quite a proud species, and they might have seen it as offensive if they were constantly asked or expected to do everything.
There's also a tactical reason why it wouldn't have made sense for the Eagles to take the Ring. For one, a giant Eagle flying over Mount Doom would definitely attract Sauron's attention. They're not exactly subtle, and there would have been no way to stealthily get to the mountain without drawing his eye. The Hobbits were small enough that they could sneak by without being detected, which made them perfect carriers for the Ring. The Eagles just simply would have been too large, and they wouldn't have been able to physically drop the Ring in the fires of Mount Doom, as there would have been no way for them to enter it. In order for the Ring to be destroyed, someone would have had to physically go in and throw the Ring into the fires.
This isn't even mentioning the fact that it's never a good idea for beings who are already powerful to try and carry the One Ring, because its power becomes too much. This is why Gandalf didn't want to hold onto the Ring, and why the Hobbits were chosen as the perfect bearers for the Ring, because of their inherent goodness. With all of this evidence, it's clear that it wasn't merely an oversight on Tolkien's part that the Eagles didn't just take the Ring to Mordor, as there are a lot of reasons why it just wouldn't have worked. Besides, what's the fun in the Eagles getting to have all of the glory instead of the Hobbits and the rest of the Fellowship?