What does the term "to weight off" refer to in ballooning?

The term "to weight off" in ballooning refers to determining the neutral buoyancy at launch. This is a critical aspect of balloon operations, as it involves establishing the point at which the buoyant force exerted by the heated air inside the envelope is equal to the total weight of the entire balloon system, including the envelope, basket, fuel, and any passengers. Achieving neutral buoyancy is essential for a successful launch because it allows the balloon to rise and maintain altitude efficiently.

Establishing this balance ensures that the balloon does not ascend too rapidly or remain on the ground. Properly managing weight is crucial for the performance and safety of the flight, allowing for adjustments as necessary throughout the flight.