In a world where Lightning Strike and his team are still going strong, what becomes of their would-be successors? As fate would have it, they all find their way to each other eventually.
Aerrow
Nephew to Lightning Strike, Aerrow idolises his uncle and his team, dreaming of the day he gets to join them. Unfortunately, his dreams are delayed when instead of being made his uncle's squire for training, he's assigned to Carver instead.
While Carver keeps trying to weasel his way into getting dates with Aerrow's (extremely not interested) mum, Aerrow finds himself grappling with jealousy towards his friends being mentored by the Storm Hawks while he isn't, and drifting closer and closer to his uncle's copilot, "Ace", than Lightning himself.
Radarr
When Aerrow was about ten years old, Lightning's Hawks were helping to bust an underground trade ring that dealt in exotic pets and slaves taken from beyond the Charted Atmos. Radarr was found by Ace in this ring, a sentient creature being sold as a potential pet. He brought the little blue furball onto the Condor with him and when he introduced him to Aerrow, the pair became fast friends.
Piper
Piper grew up at the Sky Knight Academy with her father, meeting Aerrow and Finn via their shared connections to Sky Knight society. Her hunger for knowledge and understanding of magic remains as insatiable as it is in canon, but it's now backed by access to books and other such resources on the subject. However in the Free Atmos, those resources are little less abundant than they would be in Cyclonia.
At the age of 14, she and her peers are old enough to go become apprentices and squires. Naturally, Piper chose to study under an experienced mage and was excited to be assigned to Aurora, warrior mage of the Storm Hawks and Finn's older sister. Aurora is a bit rougher around the edges than she was expecting though, and while she wouldn't say it out loud for fear of sounding ungrateful, she's also disappointed that Aerrow wasn't able to join her and Finn.
Finn
As Harrier's son, Finn Olor has a lot to live up to and he is having absolutely none of it. Like his sister, he's regularly at odds with his father, rebelling against his stifling rules in any way he can think of, from dyeing his hair, his taste in music, going so far as to change his accent to an Atmosian one in an effort to distance himself rom Harrier. If it weren't for Aerrow, he probably wouldn't have ever entertained the idea of training to be a Sky Knight.
Finn is training under Lightning's guidance. The Olors and the Strikes have a long history together, so when Finn was resistant to being Harrier's squire, he was assigned to Lightning instead. He's disappointed that Aerrow isn't joining him with the Storm Hawks, but Ace seems pretty cool and it's a chance to get to know his estranged sister again. While Lightning teaches him the essentials of being a sky knight, Finn has also taken a liking to the team's marksman, a 'cool dude' named Tyto who's taught him to customise his ride and weapons.
Junko
Similar to Finn, Junko grew up under a lot of pressure from his father, the Chieftain of Terra Wallop. In the wake of an alliance between Wallop and Cyclonia, Junko was sent to one of the Talon Academies with the intention of toughening him up so that he would fit in better among other wallops. Instead, Junko ran away and crash-landed on Terra Gale where he was patched up and offered an apprenticeship by Cooper, the Storm Hawks' medic.
Junko became fast friends with Finn and is much more of a gentle giant in this AU than in canon. He's focused on learning how to heal and rescue people than fighting daring battles, using his strength to his advantage in high-risk situations where the difference between someone living and dying is whether or not a heavy piece of rubble can be stopped from falling on top of them.
Stork
Stork was picked up a few years before everyone else, a refugee from Terra Merbia in the wake of Cyclonia's invasion of it. The Senior Hawks helped relay many younger evacuees from a drop-off point on the border or Free Atmos skies to various Terras willing to take the displaced citizens in. However Stork refused to leave, uncomfortable with every Terra he was brought to. Eventually the senior carrier pilot, Kestrel, decided to take him in as an apprentice, appreciating the merb's general quietness and meticulous repairs on the ship.