Air-time
Air time is the feeling of weightlessness or negative gravity force experienced on a roller coaster or other amusement rides. On roller coasters this feeling is usually achieved by the train going over a hill. Hypercoasters such as Magnum XL-200 at Cedar Point, Behemoth at Canada's Wonderland, Bizarro at Six Flags New England, and Goliath at Six Flags Over Georgia are known for their large amounts of air time. In addition, many wooden roller coasters, such as Balder at Liseberg, The Voyage at Holiday World, El Toro at Six Flags Great Adventure are known for their air-time.
Air-time is caused by inertia of the train and the riders. As the train goes over a hill, the mass of the riders tends to resist the downward motion of the ride vehicle, resulting in riders being briefly lifted out of their seats. The amount of airtime caused by a ride is dependent on the velocity of the train, gravity, and the radius of the track transition. Zero-G (which means zero G-force) is achieved when the downward acceleration is equal to that of gravity, while negative G-forces are caused when the downward acceleration is greater than that of gravity.
For rollercoasters there are multiple types of Air-Time:
- 1G to 0G: Float (or Floating Air-Time)
- 0G: Weightless
- 0G to -1G: Air-Time
- -1G and lower: Ejector Air-Time
Not only rollercoasters have a feeling of weightlessness, but drop towers. For example, The Twilight Zone Tower of Terror at Disney's Hollywood Studios, Disney California Adventure, Tokyo DisneySea, and Disneyland Paris have negative-G's, and the elevator drops faster than gravity would normally drop them, which causes most riders to rise off of their seats by several inches, being held down by only a seatbelt. Most drop towers have shoulder bars, which does not make riders rise off their seats (but sometimes maybe an inch or two), even if it has negative-G's and is faster than gravity, which makes the Tower of Terror at the Disney Parks a unique drop tower ride. The Mission: SPACE ride at EPCOT has a sensation of weightlessness at a point. It is a motion simulator ride to Mars, and before the ride lands on Mars, there is a weightlessness feeling.