I'm trying to get a flight mechanic so you constantly go forwards,like a plane or a bird

I am trying to make a game called “laserbirds” but The flight mechanic is like walking on air.

I don’t think there is a physics model for flight, but if you have a good grasp of maths or a willingness to learn, NASA has a great resource for basic aerodynamics.

http://www.grc.nasa.gov/WWW/k-12/airplane/short.html

It’s often necessary to simplify when you can to avoid doing a lot of calculations every frame or to collate a large table for values like the lift coefficient used to calculate overall lift. LiftEq

Helpful aproximations:

I know this probably isn’t the sort of answer you were looking for, I’m sorry to throw you to the wolves, but sometimes you might just have to buckle down and hit the books to get things done. If you’ve looked over the above and your just don’t know what to do, I can maybe try to direct you based on where you got stuck.

I think I can just make you not controlled, just go forward.

that is quite easy…the only things you have to do is to get and event called “Event Tick” and connect its execution pin to "add actor local offset " and then multiply delta seconds value from Event Tick with a float or int variable “Current Forward Speed”.[ if you want good accuracy or you want to change the speed dynamically you should use float variable]

Take the output pin from multiply and drag out to make a node called make vector, it should be connected to x axis manually. if it is not then connect it manually and take the output to the delta location input pin of Add actor local offset. and be sure to check sweep tick box.I will try to upload a picture too.