Balloons shall have radio communication equipment to allow for the communication required in accordance with appendix 4 to the Annex to Implementing Regulation (EU) No 923/2012 and, if the flight takes place in the airspace of a third country, the law of that third country.
The radio communication equipment shall provide for communication on the aeronautical emergency frequency 121,5 MHz.
GM1 BOP.BAS.355 Radio communication equipment
ED Decision 2018/004/R
APPLICABLE AIRSPACE REQUIREMENTS
For balloons being operated under European air traffic control, the applicable airspace requirements include the single European sky legislation.