Air operators may conduct check flights after maintenance to ensure the proper functioning of certain aircraft systems that cannot be verified on the ground.
A Permit to Fly is issued for Aircraft that do not obtain a valid Certificate of Airworthiness.
The continuing airworthiness of aircraft for which a permit to fly has been issued, shall be ensured on the basis of the specific continuing airworthiness arrangements defined in the permit to fly issued in accordance with Annex I (Part-21) to Regulation (ΕC) Nr. 748/2012 of the Commision.