Avatar's The Legend of Korra introduced Zaheer, an airbending villain with the unique ability of flight. He was seemingly the first airbender in a thousand years to possess this ability -- but Avatar Aang may have beaten him to the punch in The Last Airbender, shortly before getting taken down by Azula’s infamous lightning bolt in Ba Sing Se.
Long before Zaheer received his airbending, he'd admired the air nomads' way of life and studied their culture religiously. He took particular inspiration from Guru Laghima, a renowned mystic who preached a brand of air nomad spirituality that mandated complete detachment from all worldly pleasures. Zaheer's devotion gave him an almost unparalleled spiritual connection. He was able to meditate into the spirit world before he even received bending and, once he did, took to airbending like a fish in water.
Zaheer's airbending skill was impressive -- especially without formal training -- but even he couldn't achieve flight as Guru Laghima prescribed it. To do so, he would have to let go of all his earthly attachments, "enter the void and become wind." Try as he might, Zaheer couldn't quite bring himself to let go of his love, P'Li, only unlocking flight when she fell at the Beifong sisters’ hands. It was an impressive debut of the lost airbending art but, as @siccritic on TikTok noted, it might not have been the first time Avatar showed flight.
When Aang sought to master the Avatar state in The Last Airbender, he trained with Guru Pathik at the Eastern Air Temple to unlock his seven chakras. This process forced Aang to do some deep introspection and come to terms with certain truths he'd tried to ignore. Although he was raised in an airbender society, Aang still had some spiritual blocks to work through. His sessions with Guru Pathik went smoothly -- until he had to open his seventh chakra.
To unlock his final chakra, Guru Pathik advised Aang to let go of all his earthly attachments. Though it was a means to quite a different end, his recommendation was very similar to Guru Laghima's philosophy of relinquishing all earthly tethers. Like Zaheer, Aang struggled with this, and in the end refused to let go of his attachment to Katara. While meditating, he sensed she was in danger at Ba Sing Se and rushed to her side to protect her.
When Aang arrived at Ba Sing Se, he was quickly cornered by Zuko, Azula and several Dai Li agents. Realizing there was nothing else he could do, he formed a simple earth tent to protect himself and began meditating to unlock both his seventh chakra and the Avatar state. The process now came as easily as the others and he emerged from his tent fully in the Avatar state. With no noticeable wind disturbance or airbending on his part, Aang began to hover and rise steadily. Just for a moment, he’d achieved flight -- until Azula shot him down with lightning.
There's no telling whether or not Aang actually would have retained the power had this moment in The Last Airbender gone smoother, but he did fulfill all the requirements for it. Had Azula not shot him down, Aang might have become the first confirmed airbender capable of flight in a thousand years -- well before Zaheer even began studying under Guru Laghima in The Legend of Korra.
