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That doesn't fit. In Thunderbirds it's the youngest son who steps up, and four older brothers and his Dad who act as pilots usually. It's also a theatrical release, not direct to TV, and isn't considered to be about superheroes, they're a search and rescue organisation.
Perhaps surprisingly, Thunderbirds was correct (I was a toddler when I saw it, so I got a number of details wrong). Thanks for the help!
There is no war in Ba Sing Se.
This movie aired sometime in the 2000s or early 2010s. It was a live-action direct-to-TV superhero movie that followed the oldest kid in a superhero family. The family didn't really have powers; their gimmick was that they protected people by flying these airships around. The ships were definitely bird themed; they might've been called falcons. The branding of the family also surrounded birds.
The oldest kid/protagonist's arc was that some threat happened that rendered his parents unable to fly the ship. He ends up learning to fly it himself and saves the day/becomes a real hero.