Which type of parachute requires manual activation for deployment?

The free fall parachute requires manual activation for deployment because it is designed for situations where the jumper exits the aircraft and falls for a time before deploying the parachute themselves. This allows the jumper to experience free fall and control the deployment of the parachute at the desired altitude. The act of pulling the parachute's release cord is crucial in this type of parachuting, as it is entirely dependent on the jumper's timing and judgment.

In contrast, static line parachutes deploy automatically upon exiting the aircraft, as they are connected to a line that is secured inside the aircraft. An automatic parachute also deploys without requiring any action from the jumper, often used in emergency situations. A double canopy parachute is a specific design but does not inherently refer to the activation method; its deployment can vary based on its use. Each of these alternatives has different functions and deployment mechanisms, which highlights why the manual activation of the free fall parachute is a distinctive feature.