Air drop is the term used to describe the process of delivering materials, supplies or other items from an aircraft without actually landing. It is often used in situations where it is not possible for a plane to land, such as during natural disasters or in hostile territory. During an air drop, packages containing food, medical supplies and other items are released from the aircraft and parachuted down to the ground. The packages are usually equipped with GPS devices that allow them to be tracked by personnel on the ground. Air drops can also be used for military purposes, allowing troops to quickly receive supplies without having to land a plane in a dangerous region.