UPDATE: I found it!! I apologize, this wasn't an anime or a manga. This is why I was having a hard time and confusing everyone that tried to help me. It was a comic book miniseries published by IDW called Wild Blue Yonder. I'm very sorry. I got the visuals from this comic stuck in my and thought it was anime as well. I was reading it around the same time as I was watching Last Exile. The stories are kind of similar. Thank you all for your help!!
Hi, I'm new to this group and I hope you can help me remember the name of this anime movie or show. It's set in a post apocalyptic Earth where humanity is forced to live at high altitudes with bases and outposts on top of high mountains or in airships. The bad guy leader is searching for a solar powered airship fortress. He sends a man to infiltrate the crew, but the guy turns against him. I believe the lead female character flies a modified P-38 Lightening. Sincerely, Thomas