This method has evolved over the last ~30 years from its military origins into a successful method for training sport parachutists. The student gets 4-5 hours of ground training and is then taken to an altitude of about 3000 feet for the jump. The jump itself consists of a simple "poised" exit from the strut of a small single engine Cessna aircraft. As the student falls away from the plane, the main canopy is deployed by a "static line" attached to the aircraft. The student will experience about two to three seconds of falling as the parachute opens.
Subsequent S/L jumps require about 15 minutes of preparation. After 2 good static line jumps, the student will be trained to pull their ripcord for themselves. The student then does 3 more static line jumps where they demonstrate this ability by pulling a dummy ripcord as they leave the plane (the static line is still initiating the deployment). The student is then cleared to do their first actual freefall.
The first freefall is a "clear & pull", where the student initiates the pull sequence immediately upon leaving the aircraft. Next is a 10 second delay jump. Subsequent jumps go to progressively higher altitudes with longer delays. After 20 freefalls, and meeting certain other basic requirements, the student receives their A license and is cleared off student status.