Generation 1 Animated Series
On the planet of Cybertron long before the war, Skyfire (voiced by Gregg Berger; he was called Skyfire because of legal reasons involving Macross) was a scientist and an explorer working with the future Decepticon Starscream. Together they investigated our planet, this of course being before other Transformers would land on the planet, where to their dismay, they failed to find any kind of intelligent life. Skyfire wished to further continue his research, and while moving in close enough to the planet, a snowstorm swept him up and buried him beneath the arctic ice near the pole. Starscream claimed to have searched for him, but would return to Cybertron alone. Many years later he would be revived by Megatron and Starscream, who convinced him to join the ranks of his fellow Decepticons. The Autobots would later arrive on the scene, where Skyfire engaged in battle against them. When two humans were endangered, Skyfire would spring to save them from harm. He would take the two to Megatron, not realizing what Megatron would do. Megatron then took them as prisoners, causing Skyfire to question his allegiance, and after refusing to destroy an Autobot search party, Starscream attacked him. Thus, Skyfire changed his allegiance and joined the Autobots. Throughout the rest of the series, Skyfire would be a valued Autobot, though he didn’t appear often, and the other Autobots would not trust him, considering his past.
Marvel Comics Series
In the Marvel run of Transformers, Jetfire is introduced in the 11th issue, where he is a creation of Shockwave's designed to take out the Autobots.
In Dreamwave's 21st century re-imagining of the Generation 1 universe, Jetfire is presented as Starscream‘s friend before the war. Jetfire was slow to pick a side when the war broke out, but fortunately for the Autobots, he eventually sided with them. Despite the fact that he even remained with the Autobots when Optimus Prime and Megatron vanished in an early space bridge experiment and the factions splintered into smaller sub-groups, his prior hesitance and prior friendship with Starscream caused other Autobots weary of him, and this lead to mistrust . A fierce grudge was redeveloped by Dynobot commander Grimlock against him for an unspecified incident involving a mind-controlling cerebro-shell, and was perfectly ready to believe that he had betrayed the Autobots when he arranged a meeting with current Decepticon leader Shockwave. Jetfire was among the Transformers kidnapped by the ancient Cybertronian called The Fallen, who planned to use the genetic potential in his spark to awaken Primus, but he was freed by Grimlock, putting the grudge to rest as the two would work together.
Prime and Megatron subsequently returned to Cybertron, but when they and their elite crews were lost aboard the Ark, Jetfire was part of a mission to find them, along with Omega Supreme and the Micromasters Countdown and Groundshaker. When a lead emerged in the form of a beacon from the Sol system being detected, Jetfire and Omega split off from the team (who went on to investigate Decepticon attacks on other planets) and headed off after the signal. The duo entered stasis for the lengthy trip, with Jetfire eventually awakening millions of years later as their craft approached Earth. Before Jetfire could bring Omega back on-line, however, their ship was attacked by the futuristic Decepticon Scourge and crashed in the Arctic, where shrapnel from a ship would accidentally kill a pod of whales. Jetfire ejected from the ship before impact and managed to seal Scourge in a stasis pod, but an avalanche buried both of them in ice (a homage to the G1 cartoon).
At an ill-defined point in time, the Decepticons discovered Jetfire and would bring him back to a base. Upon returning from a trip to Cybertron with fresh plans of conquest, Starscream thawed Jetfire out to aid in repelling the maniacal Sunstorm, a clone of himself that Shockwave had created, who had gone insane from an overdose of energy. Deducing Sunstorm's clone nature, Jetfire designed a power siphon to de-energize him, and then reactivated Omega Supreme to battle him. To save his own skin from Autobot retribution, however, Starscream had a change of heart and saved Sunstorm, who led him to a mysterious underground energy reservoir that Starscream would receive powers similar to those of Sunstorm. Yet another double-cross by Starscream saw Sunstorm immersed in the liquid , and it began to destroy him from within as Jetfire battled him. Jetfire chose to lead him into space as a last resort where Sunstorm exploded, taking the Autobot with him.
Transformers: Revenge of the Fallen - In the film, Jetfire (voiced by Mark Ryan) is a veteran Transformer who decided to leave behind the war and the Decepticons. He is discovered by Sam, Mikaela, Wheelie, the Twins, Leo, Bumblebee and Simmons as they need him to decipher the text Sam continues to see. They realize time has taken its toll on Jetfire as he has some difficulty transforming; he also uses a landing gear as a crutch, and has forgotten what planet he is on. Jetfire teleports the group to Egypt to find the Tomb of the Primes, as he explains that the Primes sacrificed themselves to hide the Matrix of Leadership from the Fallen in order to stop him from using the Sun Harvester to destroy the Earth's sun. The Matrix also has the potential to bring Optimus Prime back online as only a Prime can defeat the Fallen. Jetfire joins the battle to fight off the Decepticon army but is gravely injured by a surprise attack from Scorponok, whom Jetfire destroys. In his last moments, he offers his parts to help the newly revived Optimus to defeat the Fallen and rips his spark out, dying. This gesture helps Optimus to destroy the Sun Harvester, beat Megatron into retreat and ultimate destroy the Fallen, saving Earth.
Transformers: War for Cybertron - Jetfire appears in all versions of the game and as the alternate form of a Cybertronian Jet and is voiced by Troy Baker. Jetfire first appears as one of Starscream's partners on the station that houses Dark Energon and Jetfire tries to reason with Megatron when he appears to claim it for himself. Jetfire later flees the scene once Starscream gives his allegiance to Megatron and goes to the Autobots in order to warn them of the danger. After making contact and joining the Autobots Jetfire alongside Air Raid and Silverbolt is tasked with destroying a Decepticon Satellite which is destroying fleeing Autobot ships. The trio take out the stations cooling and pulse stations only to realize that the space station is actually a giant Decepticon named Trypticon. The trio take out Trypticon's transforming cog which forces him to transform and then they shoot out Trypticon's jet pack which then allows Optimus' ground team to finish of the giant Decepticon.
Transformers: Fall of Cybertron - Jetfire appears again as a member of the Autobots and is still a Cybertronian Jet.Jetfire first appears next to Optimus when Megatron begins his siege of the ark. Jetfire flies ahead to meet with Ratchet in order to aid in defense of the Ark. Jetfire appears near the end when the Ark is under attack from Megatron's flagship Nemesis which is a re-purposed Trypticon. Jetfire uses his rocket launcher to destroy the Nemesis' tow cables that have hooked onto the Ark. Jetfire then aids Jazz in his fight with Bruticus which is the combined form of the Combaticons (Onslaught, Brawl, Blast Off, Vortex, and Swindle). Jetfire drops EMP mines given to him by Ratchet and then performs bombing runs alongside Air Raid and Silverbolt when Jazz calls for it. They are successful in knocking Bruticus off the Ark and into empty space.