You can use this form to apply for an air traffic control clearance for the ascent of your unmanned free balloon (‘weather balloon’). Your application will be automatically checked and then either answered directly or forwarded to the responsible contact person for processing on the basis of §21 LuftVO and DVO (EU) 923/2012 SERA.3140. Please ensure that you can be reached at the number provided (mobile phone) during the implementation of the project.