The exact type of plane that he took on a final joyride a year later.
We can assume that this was his favourite plane and that, while on his job, after the pilots parked it and went for a coffee break, he was alone with it in the hanger when inspiration struck. He climbed into the vehicle that tugs jets around the tarmac and turned the Alaska Air Q-400 back around. At this point he climbed on board, flipped the starter switches and made for the runway.
In that hanger, he was captivated with sublime inspiration to just seize the moment and take to the air with it, to perform aerial maneuvres that left seasoned pilots baffled that the aircraft, let alone an untested pilot could handle. And even that, was framed with meme magic given the timestamp of his conversation with air control:
After accomplishing his barrel roll, he was stunned to have even completed it. in that moment he accomplished his dream, the climax of his passion in this favourite aircraft of his. Soon after, entering the denouement of his flight, and life. His final moments likely reflecting on what he had just done. It must’ve been enormously, sentimentally significant.