A permit to fly is required if the airworthiness of an aircraft is limited for administrative or technical reasons.
In order to obtain a permit to fly, a distinction has to be made between two application procedures. If the safety of design of the aircraft should be affected, the application has to be assessed and approved by the EASA (EASA Form 37).
If the safety of design is not affected, the Federal Office of Civil Aviation (FOCA) is responsible for handling the entire application (EASA Form 18b). Cases in which responsibility lies solely with the EASA:
- If the aircraft does not meet the requirements of the type certificate
- If an airworthiness limitation, certification maintenance requirement or airworthiness directive has not been complied with
- If the intended flights are to take place outside the approved flight envelope