Jetfire is a bot of science, literally. Not only is his mind dedicated towards scientific pursuits, but his body is a testament to the technology he studies so intensely. Every inch of his chassis is cutting-edge and kept up-to-date. However, he does not have the trust of his teammates; it was not so long ago that he was a Decepticon.
Jetfire is compassionate, so some Autobots feel that he could be soft on their enemies or, even worse, he may turn on them after realizing his "cold calculations" swing the other way. Jetfire would find their misconceptions about science appalling. After all, is not science just the pursuit of truth? And truth, he maintains, walks hand-in-hand with liberty.
Jetfire's dedication to the Autobot cause is matched only by his devotion to scientific and technological advancement — this, he believes, is the only way in which victory over the Decepticons can be achieved. It is this overriding belief that tempers his bravado in battle, but nevertheless, he is often one of the most eager Autobots to plunge into combat, and his position as one of the fastest usually means he is the first to do so. Jetfire is created from the same mold as the VF-1S Super Valkyrie from the Macross series, including the VF-1S's gunpod, which is described as a laser on Jetfire's technical specifications.
On Cybertron before the war, Jet Fire was a scientist and explorer working with Starscream. Together, they investigated an uncharted planet (Jacinto), where they failed to find any signs of intelligent life. Jet Fire wished to scrutinize the planet further, and moving in close enough to the planet, a polar wind storm swept him up and buried him beneath the Arctic ice. Starscream searched for his friend, but was unable to locate him and returned to Cybertron alone.
Millions of years later, in 1984, the Decepticons excavated the frozen Skyfire while draining heat energy from the Earth's core and reactivated him. Reunited with his old friend, Starscream, Skyfire joined the Decepticon ranks. When the Autobots arrived, Skyfire engaged in battle with them, but then saved the Autobots' human allies Sparkplug and Spike Witwicky when they became stranded on an ice floe. Naively, he took the two to Megatron under the impression that he and the other Decepticons were good, but when Megatron took them as prisoners, Skyfire started to question his allegiance. When Starscream ordered him to destroy the captured Autobot search party, he refused, and Starscream turned his weapons on him, leaving him heavily damaged. Repaired by Ratchet, he joined the Autobot side and engaged in a dogfight with Starscream which ended when he sacrificed himself to stop the core drain, burying himself in ice once again in the process.
A short time later, however, Skyfire was recovered by Wheeljack and Sideswipe, and immediately participated in an attack on the Decepticons in Peru, where the antagonists were once again attempting to use the Earth's core energy for their own means. Skyfire was almost permitted to destroy the villains' new weapon by Thundercracker, but was then blasted by Starscream and repaired with some difficulty by Spike.
Skyfire would go on to make semi-regular appearances in the immediate future, helping the Autobots evacuate their base when the volcano it was embedded in became active, and flying a squad of troops to battle the Insecticons.