Snowboarding in a half pipe allows for some interesting variations on standard tricks and opens up new possibilities for old tricks. One great trick to learn that has many possibilities is the 180-degree turn. After learning the 180-degree turn the first variation of it is the Alley Oop. To begin let us look at the basics of a 180-degree turn in a half pipe.
The first step to a 180-degree turn is to become very familiar with the half pipe and getting air in it. Make sure you are very proficient at pumping the ramp and doing an Air-to-Fakie before proceeding. These are very basic maneuvers that will allow you to gain enough momentum to get air and be able to land it successfully. Learning to ride and land Fakie is very important to snowboarding in a half pipe.
Once you are confident at getting air in the half pipe you can begin to practice 180-degree turns. Doing a 180-degree turn is a lot like doing one on the ground. You want to be as low as possible, pre-load your body for the turn and react quickly and cleanly. The importance of pre-loading your body can not be stressed enough as it is the key to generating enough momentum to do and stop your 180-degree turn and allows you do progress to 360-degree turns and beyond. You can easily pre-load your body by twisting your head and shoulders in the direction that you intend to turn.
As you ride up the transition crouch down and center your weight on the snowboard. As you pass the vertical section of the half pipe lean forward and begin to pre-load your body. Once you get air release the energy you have stored up by looking at the point where you just left the ramp and rotate your hips. As your body and snowboard follow through keep a close eye on the vertical section just above the transition as this your landing target. Failing to do so may result in your catching the edge of the ramp on your way back in. As you re-enter the half pipe and clear the lip, extend your legs so that your snowboard makes contact with the vertical section and ride out your trick.
Once you have done a few 180-degree turns you can vary it by turning it into an Alley Oop. An Alley Oop is a 180-degree turn done in the opposite direction of the transition that you are riding. If you are riding up the front side of the half pipe then you need to rotate to your backside to Alley Oop. Conversely, if you are riding up the backside of the half pipe you need to rotate to your front side to Alley Oop. Other than the direction of the rotation an Alley Oop is identical to a 180-degree turn.
As you can see the Alley Oop is a 180-degree turn in specific directions. Due to the nature of riding in a half pipe this will undoubtedly be one of the first aerial tricks that you learn and will lead you to new tricks fairly quickly. Getting air and learning to control it as well as learning the zones of a half pipe are all critical steps to mastering the half pipe.