Release a balloon requires to comply with the law. In France, the regulations that apply to sounding balloons (“Ballon Not Lived Free” under the law) is defined in Règles de l’Air.
The regulation classifies balloons into 3 types according to several criteria. Our ball Ptimulus # 1 was “light” type. Regulations that apply to the types of balloons “light” simply indicates to “an appropriate authorization from the competent authority.” We contacted the Directorate of Civil Aviation Security North East which, after some discussion about our project, gave us permission to launch our balloon. The launch of our balloon was subject to technical constraints (presence of a radar reflector, speed limit drops, weight, …) and administrative (different entities inform air traffic control, …).
Si You want to venture into, it is imperative that you contact the DSAC in your area to obtain authorization before launching your ballon. Do not launch a balloon without permission JAMAIS CASD. Obtaining permission to CASD can take several months. Contact your local CASD at least 6 months before the date of your ball dropped.
In addition to the authorization to shoot the ball, it must also get permission from the owner or operator of the land which the dropped ball be made. You probably will not have trouble finding land, but mind you well in advance also.