## 5 Results: Application of the European Drone Regulation to Mosquito Release Operations
### Alternatives to Relax Risk Levels  
Certain operational conditions can help relax risk levels and have less demanding mitigating measures. The environment in which the release of sterile mosquitoes is the most important is the urban scenario. At the same time, this scenario is the most complex due to the conditions that exist in this case: normally they are immersed in the airspaces affected by the nearby airports, they are populated environments with the presence of people on the ground, and there is more possibility of traffic from other aircraft (emergency, medical and police helicopters, etc.). However, it is important to note here that there is a current discussion between the different stakeholders on how to redefine and redistribute airspace. Currently, controlled airspace in urban areas covers most of the urban volume from ground to high altitude due to the proximity of their airports, so any drone that wants to fly in VLL would be in controlled airspace. That is why the drone and airspace community is studying relaxing the airspace distribution and starting from different heights depending on the distance to the airport, establishing a kind of cone to categorize the airspace. According to the European drone regulation [14], drone operations can be included in the open category if they are considered low risk operations. The main characteristics of this kind of operation are that the drone should have a CE mark, weigh less than 25 kg and be operated in VLOS or assisted by an observer, and that the maximum height is 120 m. Today, the ASD-STAN organization has established a D05/WG08 working group called the UAS unmanned aircraft system, in which standardization activities are being developed for the definition of means of compliance to obtain the CE mark. Furthermore, there is one major restriction regarding the impossibility of carrying dangerous goods or dropping any material. This last aspect is crucial when it comes to discerning with the aviation authority the possibility of including this type of mosquito release operation in the open category. This must be further discussed with the aviation authority to reach an agreement. By analyzing the different operational alternatives of the open category for mosquito release operations, options that include flights in urban environments will be highlighted. Within the subcategories into which the open category is divided, those particularities that affect the urban environment are as follow. * Subcategory A1: The drone can fly in urban areas but not over an assembly of people and is trying to reduce overflying uninvolved persons. If uninvolved persons are overflow, the remote pilot must reduce as much as possible the time during which the drone overflies those persons. Apart from that, maximum take off weight (MTOW) of drones in this subcategory can be up to 900 g.
* Subcategory A2: The drone can fly in urban areas, but a safety distance of at least 30 m must be maintained with respect to the uninvolved people in the operation. In this case, the drone can weigh up to 4 kg. The STS-01 standard scenario analyzed above in Section 5.1 is considered to be an extension of the A2 subcategory of the open category because of the similarities in the conditions and requirements that are posed. However, operations in an urban environment can fall under these two subcategories within the open category as long as they comply with the airspace restrictions imposed by the national civil aviation authority. This is the point that differentiates these subcategories from the STS-01 approach raised in Section 5.1, since most authorities reject the possibility of flying the open category in controlled airspace, in which most cities with nearby airports are immersed. Therefore, there is a current trend of redefinition of airspace in cities, which would allow the dimensions of these controlled spaces to be relaxed by not reaching the ground when there is a certain distance from the airport.