"Wonderbolts Academy" isn't universally adored on the same level as "Sleepless in Ponyville", but it's almost as good. When it aired, it was one of my favourite episodes of the season, a title which it retains. As an episode, it not only contains notable character development, but in fact is one of the first to push a character closer to their goals. Add to that some great action, and you have a fantastic episode.
This episode is notable for providing a stepping stone on Rainbow Dash's journey to join the famous stunt flying team that she idolizes. Of the main characters, she's perhaps the only one with a consistent, long-running goal, though until now it was mostly treated as a pipe dream that at most would maybe come true much later. However, with this episode, suddenly she seems to be on a path to achieving this dream. It's intriguing that the show's moving in this direction, because that's a considerable disturbance of the status quo.
The character development that Rainbow Dash has experienced over the course of the previous two seasons is readily apparent here. As I've repeatedly mentioned, Rainbow is far more mature than she was initially, and her hesitation to take extreme risks definitely reflects that. It's nice to see again that these characters do grow, and indeed Rainbow experiences further growth in this episode. She's faced with a dilemma: Worry about fairness and the safety of others, or push herself further and potentially improve her chances of fulfilling her dreams? It's not an easy question, and Rainbow's answer to it reflects how her values have matured over the course of the show.
The new character introduced, Lightning Dust, is an interesting one. She acts irresponsibly and recklessly, and at times her recklessness can get irritating. This is magnified by the mediocre performance of her voice actor, who occasionally lapses into a slightly obnoxious tone. Lightning Dust also has a certain disregard for the safety of others, clearly not caring much for the consequences. Still, of the antagonistic characters we've seen in this show so far, she's the mildest by far. This is particularly interesting in the ending, where she seems to realize what she did wrong as she walks off. I might like to see her appear again, perhaps as a friend this time.
One thing that really catches the eye is how action-packed the episode is. There's a number of action scenes, which is fitting as much of the episode revolves around flight tests. The trials have increasingly interesting visuals, and there's some spectacular camera work. A real sense of speed is conveyed, and a number of interesting visual elements are used. This results in action scenes being exciting and energetic, and plenty of fun to watch.
With "Wonderbolts Academy", S3 can surely be seen to have hit its stride. The exciting action would already be enough to make the episode entertaining, but how it pushes Rainbow closer to her goals and provides compelling character development elevates the episode to greatness. It's around this point that S3 really gains its footing, though with the short length of the season it wouldn't be for long.