Generation 1: The flight capable characters where somewhat inconssitent for the pre-movie episodes, both sides able to fly. After a the movie, Autobots with flight ability: Dinobots, Arielbots, Blades, Sandstorm, Springer, Powerglide, Omega Supreme, Fortress Maximus, Strafe, Scattorshot All Decpticons could fly Beast Wars: Maximals with flight Optimus Primal: Able to fly throughout the shows run Airrazor: Able to fly for the duration of time on the show Cheetor: Flight capable Season 2 and 3 Tigerhawk, Depthcharge, Silverbolt, flight capable Predacons Terrorsaur Waspinator Inferno Megatron (season 2 on) Beast Machines Only Optimus, Nightscream and Silverbolt, Jetstorm, Vehicon flight drones, Obsidian and Megatron could fly Robots in Disguise: Skyshark, Recolored Vortex and Blast Off, Megatron/ Galvatron Armada: Autobots Jetfire Optimus (when combined with Jetfire) Decepticons Megaron (when combined with Tidal Wave) Tidal Wave Starscream Thrust Cyclonus Energon: Who couldn't fly? Cybertron Autobots Jetfire Optimus Vector Prime Evac Wing Saber Decepticons Megatron Starscream Thundercracker Brimstone Sideways Soundwave Animated Autobots Optimus (with flight pack) Prowl: With armor Omega Supreme Jetfire and Jetstorm Most Decepticons could fly, same for the Bayverse Prime Autobots: They have yet to reveal any Autobots who could fly on screen, though I think the Dinobots, or at least Swoop, would have flight Decepticons Megatron Sounwave Starscream Skyquake Dreadwing Jet Vehicons
I think only Transformers with flight-capable alt-modes should be able to fly. Hell, I actually prefer having it be only Decepticons who can fly, like in TFA.
I think as long as their robot mode has some visible means of propulsion/levitation (like a jet pack or something), any TF should be able to fly, even if they don't have an ariel vehicle mode (I'm not saying every TF period should be given flight, I'm just saying it shouldn't depend entirely on alt mode).
I've always thought that they all had some sort of jet boosters in their feet or wherever and that they could use those to jump or even fly under lower gravity. Kind of like in WFC and FOC. I swear they mention something like this in the novel, Ghosts of Yesterday, as well.
