Airbrakes?

Thanks for the suggestions but I saw this one post that had airbrakes that used a piston and to be a hydraulic something that lifts up the panel and I was hoping someone would explain how to make that but guess I'll try what you said.

yeah, just put a flat panel on hinges or rotators, or use the reverse thrust on jets (on default, hold brakes until throttle bar goes down, then it will enter reverse thrust mode, then due to the throttle lowering to 0 it will go back to 0 thrust, no idea why they made it like this but you can rebind it)