Jet-copters are Red Ribbon Army-owned aircraft that were utilized by the Blue Corps.
Similar to several other Red Ribbon Army materials, they were kept within a Capsule. As implied by the name, the jet-copters resembled a hybrid between a jet and a helicopter. They were also colored white and had unit markings on the side as well as the name "Red Ribbon", although in the film Path to Power, they were colored blue instead, presumably to better fit the theme naming of the unit and its leader, and also green for the ones stationed near the Red Ribbon Army Headquarters.
Two Red Ribbon Army pilots, after Bulma refused their attempts at sexually assaulting her, attempted to pursue her with their jet-copters, also firing at her, although Goku wiped the two out effortlessly, with their boss General Blue having witnessed the entire thing from afar, causing him to realize Goku is not to be underestimated as an opponent.
Later, Scout 0-1 utilized the Jet-copter to scout ahead to Kame House and gather intel on the inhabitants, eventually reporting back that the inhabitants besides Goku included a girl, a Turtle, and an old man, and they had no apparent form of defenses.
Bulma and Krillin, shortly after escaping from the Pirate Cave, stole a Jet-copter (designated Unit 72) from General Blue's Camp to leave the camp for, while Goku used the Flying Nimbus after making sure he got some food. General Blue himself used one (designated Unit 20) shortly after returning to his by that point deserted camp after executing the last member of the corps for cowardice (as he had hid from Goku, Krillin, and Bulma earlier) and sleeping on the job, in order to locate Kame House so he could personally trap them as revenge for his defeat at the Pirate Cave. He then had it continue flying unmanned after finding it while he jumped out with rope in hand.
Just prior to General Blue's arrival, Launch, who by that point had reverted to her bad self, stole a diamond that Bulma and Krillin retrieved from the Pirate Cave and made an escape via the jet-copter Bulma and Krillin used earlier to arrive at Kame House.
Two jet-copters were later present at the Red Ribbon Army Headquarters, where they attempted to shoot down Goku, but were destroyed.
In Dragon Ball: The Path to Power, the jet-copters made a brief appearance among General Blue's unit when they invaded Kame House. They were slightly redesigned to be colored blue befitting their leader's namesake color.
Later on, several tried to pursue Goku in the forest as he traveled to the Red Ribbon Army Headquarters, although they ended up crashing due to the presence of trees. They also were slightly redesigned, although that time, they were colored green.