I dont see many posts for Chipper on here, so here are my ideas for him!
His callsign "Chipper" is to highlight that he is actually kind of frown master and not very social. He's a little bitchy and has a tendency for attitude, this comes from a place of having a hard childhood and having the mentality of "I have to get them first before they get me". He doesnt trust easy and thus wasn't looked upon as a team player and as a lone wolf.
It wasn't until he met Sundown who gave him some tough love, yet support and understanding. He cared for Chipper and he was hurt a lot by the pilot's harsh exterior, but he also saw how others picked at him to rile him up and gave him his callsign as a joke to laugh at (most callsigns are mean to be a joke, but this was cruelty)
Sundown showed him compassion and tough love cause Chipper could act like a little bitch for random reasons and Chipper soon grew to be more open about his feelings and learned how to trust. Sundown then introduced Chipper to his friends (Mav, Goose, Ice, Slider, Hollywood, and Wolfman) and he started to let his walls down and find trust in his new support system.
Sundown and Chipper's wedding was the third 86' flyboys wedding after Icemav and Hollywolf!!!