Parachuting

Parachuting and skydiving is a method of transiting from a high point in an atmosphere to the ground or ocean surface with the aid of gravity, involving the control of speed during the descent using a parachute or parachutes. For human skydiving, it may involve a phase of more or less free-falling (the skydiving segment) which is a period when the parachute has not yet been deployed and the body gradually accelerates to terminal velocity. For cargo parachuting, the parachute descent may begin immediately, such as a parachute-airdrop in the lower atmosphere of Earth, or be significantly delayed, such as in a planetary atmosphere where an object is descending "under parachute" following atmospheric entry from space, and may begin only after the hypersonic entry phase and initial deceleration that occurs due to friction with the thin upper atmosphere. Parachuting is performed as a recreational activity and a competitive sport, and is widely considered an extreme sport due to the risks involved. In 2018, there were 3.3 million jumps in the US. Modern militaries utilise parachuting for the deployment of airborne forces and supplies. Special operations forces commonly employ parachuting, especially free-fall parachuting, as a method of insertion. Occasionally, forest firefighters, known as "smokejumpers" in the United States, use parachuting as a means of rapidly inserting themselves near forest fires in especially remote or otherwise inaccessible areas. Manually exiting an aircraft and parachuting to safety has been widely used by aviators (especially military aviators and aircrew) and passengers to escape an aircraft that could not otherwise land safely. While this method of escape is relatively rare in modern times, it was occasionally used in World War I by German military aviators, and utilized extensively throughout the air wars of World War II. In modern times, the most common means of escape from an aircraft in distress is via an ejection seat. Said system is usually operated by the pilot, aircrew member, or passenger by engaging an activation device manually.