Skyborg was once Jud Harmon, a test pilot who competed fiercely against Race Bannon until, in an effort to outfly Bannon, he flew too high and lost consciousness. The unpiloted fighter jet subsequently crashed into a mountain, and Race assumed Harmon had died. In reality, Harmon survived and was found by agents of an unnamed foreign power. He was revived and augmented with cybernetic body parts. Taking the name "Skyborg," he became a ruthless mercenary pilot who worked for the highest bidder. He blamed Race Bannon for his predicament.
The same foreign power which gave him his robotic body parts hired Skyborg to steal the CAP from Dr. Quest. During this he encountered Race Bannon once more and revealed how he had survived. A military officer from the foreign government instructed Skyborg to test out CAP, and so Skyborg installed the computer in his own jet. Holding Quest hostage, Skyborg told Race to take another jet and be the target of his test. With little other choice, Race agreed.
Jonny and Hadji, who had arrived with Dr. Quest, snuck aboard Skyborg's jet. In an effort to hit Jonny with his metal fist, Skyborg accidentally smashed CAP. The jet crashlanded in the ocean and sank. Although Jonny, Hadji and Dr. Quest got out, Skyborg had been knocked unconscious. Race dove underwater and rescued his former rival, for which Skyborg was grateful. He opted to take back his former identity of Jud Harmon and and turn himself in to the authorities for his crimes.