Each contest flight usually consists of 6-8 planes. Each plane must have a pilot and a "delivery specialist" (aka bombardier). Each plane will be given 3 nerf balls, with sequence numbers written on them (e.g. the 3rd plane gets the nerfs marked "3").
All the planes in each flight lined up then launched about 5-10 seconds apart. Each plane follows the plane ahead and makes one nerf drop from 200' AGL, then the whole flight comes around and make one spot landing. Do that cycle a total of 3 times.
The target for the nerf drop is a plastic kiddie swimming pool. Judges on the ground measure the distance from the target to where the nerf hit and give you a score. Add up the scores from 3 nerf drops to get your total score. There are people on the ground holding flags to give you an idea of wind direction and velocity.
For the spot landing contest, there are two green lines painted about 80' apart on the runway, creating Green Acre. You try to touch down (with any part of the airplane) within the green acre. Outside the zone gets 0 score. Scores are also given for "style and grace".
Take a look at these videos to get an idea of the process.
Clinton 2013 Flying Contest - Part 1 [
youtube.com]
Clinton 2013 Flying Contest - Part 2 [
youtube.com]