How do I get air time on a coaster - the objective says at least 5 seconds of air time
To expand a bit on airtime....
If using hills to create airtime, you have to keep a few things in mind.
#1: Speed
If you're trying to get airtime at the top of a fairly big hill, you want the coaster to be moving about 30-35mph when it goes through there. Any slower and you don't get much if any airtime, and can even lose excitement. Any faster and you push too many negative Gs, so increase fear and nausea. Towards the end of the ride, when the coaster is down to that speed more or less anyway, you can create a section of small undulations in the track just before the brake run, which is often necessary to keep that slow part of the track from being so boring it ruins the overall ride rating.
If you're doing a double-up or double-down instead of a single big hill (IOW, making like a stairccse instead of a smooth slope), you can be going faster, but the individual bumps need to be pretty small, This is again ti minimize the negative Gs.
#2: Flatness
It seems to be a quirk of the game that you only get airtime if the track at the top of the hill/bump is straight and unbanked. If there's any bank and/or curving, then often you get zero airtime, or only 1 or 2 rows of seats in a long train will, which doesn't seem to count for your score. But OTOH, you can often use this to your advantage. If you have to make a short straight and level piece of track somewhere in the middle of the run anyway, you can turn it into a block brake, which helps you run multiple trains without one of them pausing at the top of the lift. Just be sure to adjust the brake's settings so it won't slow the coaster down as it goes over.
The other main method for creating airtime is to use outside banking on turns. This is much more difficult to achieve because, of course, the track is neither straight nor unbanked. But it is possible.