Regulation (EU) 2018/395

1. The pilot-in-command shall ensure that no person carries and uses a weapon on board the balloon.
2. By way of derogation from point (a), the pilot-in-command may permit the carriage and use of weapons on board the balloon when required for the safety of the crew members or the passengers. In such cases the pilot-in- command shall ensure that the weapons are secured when not in use.

BOP.BAS.145 Meteorological conditions