ED Decision 2009/005/R
The range of masses over which the balloon may be safely operated must be established and at least consists of:
requirement is shown. (See AMC 31HB.14(b))
Mass limitations between which the balloon may be safely operated must be included in the Flight Manual. (See CS 31HB.81(b)(2))
ED Decision 2009/005/R
The maximum mass corresponds to the maximum buoyancy. The lift-producing medium is not part of the maximum mass.
ED Decision 2009/005/R
Minimum mass: In arriving at this figure, especially with larger balloons, attention should be paid to the ability to properly operate the balloon, in terms of both its heating and venting, with the reduced envelope rigidity associated with low mass operation.