Category A1 (Open) is part of the "Open" operational category, which covers drone flights posing a low risk to the surroundings. This subcategory is intended for the lightest drones, specifically those with a C0 class certification label weighing up to 250 grams or C1 up to 900 grams. It also includes privately built drones or older models without a label, weighing up to 250 grams. The main rule for A1 is that the pilot may overfly individual uninvolved persons, i.e., people who are not part of the drone operation, but must not fly over crowds of people. For flying drones under 250 grams, it is necessary to familiarize oneself with the manual, and if the drone has a camera or other sensor capable of capturing personal data, registration as an operator is required. For drones in class C1 (250–900 g), it is additionally mandatory to complete an online course and pass a test to obtain a proof of competency.
