>>8969148 In the original 3 parter, all the Autobots could fly (Optimus needed the jet pack to fly all the way up after the Decepticon spaceship)
This was something that kinda was phased out from the later episodes, I assume for drama sake(though there is the occasional exception). It worked better that only the Decepticons could fly even if it didn't make much sense that the Decepticons could fly but the Autobots couldn't
