Freeflying is an expansion of skydiving which includes the traditional belly-to-earth positions, but extends into vertical flight where the flyer is in an upright position (falling feet first) or in an inverted position (falling head first). These positions increase freefall speeds and make new types of formations and routines possible.
A freeflyer, in order to fully understand the aerodynamic power of his/her body in freefall, needs to first learn to control all of the skydiving forms: box position (belly-to-earth, traditional skydiving position), back flying (back-to-earth), head-up flying, head-down flying, and side flying. These positions are not held for the duration of a skydive. Freeflying can, and usually does, involve constant transitions in position and speeds, with vertical and horizontal orientations. This can involve constantly flowing skydives, with all positions explored, or more static skydives where flyers are concentrating on building a large formation while flying in one of these freefly positions.
Due to the increased freefall speed and potentially faster horizontal speeds, freeflying has dangers beyond that of a normal skydive. Extra care must be taken for freefall skydive groups to stay away from belly-to-earth skydivers to avoid collisions. Since most parachutes are not designed to be opened at speeds higher than that of normal belly flying, freeflyers must transition back to the “belly to earth” position and slow down their descent for several seconds before deploying their parachute.
While freeflying is a younger and more extreme addition to skydiving, it is becoming a popular event in competitions and world records (see Vertical formation skydiving).
Back flying is the ability to fly on the back in a stable and controlled fashion. This skill is critical so that when the flyer flips out of some of the more advanced positions they stay in control and do not endanger themselves or other skydivers.
Sit flying is called such because it looks similar to the position taken while sitting in a chair. For flying a sit, the feet are oriented toward the relative wind and 90-degree bends maintained at the knees, hips, and shoulders. To move around, the flyer redirects the airflow in the opposite direction the jumper wants to go. Newtonian mechanics then push the flyer in the desired direction. Fall rate changes (descending faster or slower) can also be made.
A person falling in the head down position has less surface area exposed to the air while falling, which results in much faster fall rates. Average speeds while flying head down are around 160 mph. Due to the increased speed, every movement made can cause the skydiver to become unstable or disoriented; thus increasing the risk involved in skydiving.