Much like projectile vomit. In most average cases shit comes flying out of one's ass at 5000 miles per hour and rips your ass cheecks off, therefore leaving you assless for the rest of your life, unless the ass fairy comes in and creates new ass cheecks out of chicken fat for you.
When a fart emerges with such power and velocity that it can destroy and level all man-made structures within a wide radius.
His recent projectile asshole tornado was mistaken for an actual weather event by the National Weather Service when it virtually devastated an entire small midwestern town.
Projectile ejaculation is where you masturbate until just prior to ejaculation, and then you hold it carefully back until somebody you really dislike is nearby and you let go, hitting them in the face or hair with a loud, wet SLAP.