When should the deflation port (rip panel) be opened during landing if rapid deflation is required?

Opening the deflation port, also known as the rip panel, prior to ground contact is crucial for controlling the descent and managing the landing of a lighter-than-air craft effectively. When rapid deflation is required, activating the deflation port before touching down helps in reducing the lift and forward speed of the balloon significantly. This proactive action ensures that the balloon descends more safely and can help prevent a hard landing.

By initiating the deflation process before ground contact, the pilot can better manage the balloon's descent rate and trajectory, effectively stabilizing the craft before it makes contact with the ground. This maneuver also helps in preventing potential damage to the balloon and decreases the risk of accidents during landing.

In contrast, if the deflation port were to be opened after the balloon has touched down, or at a stable altitude, it would not provide the same level of control over the landing process. Opening it at the highest point of descent does not allow for optimal descent management and could lead to an uncontrolled approach. Hence, the selected approach of opening the deflation port prior to ground contact is the most effective method to achieve rapid and safe deflation upon landing.