# Short-Range Transportation Using Unmanned Aerial Vehicles (UAVs) during Disasters in Japan
## 4 Discussion  
This series of transportation experiments showed that under the autonomous control of the pilot and the flight instructions of the assistant, UAVs were able to safely transport 17 kg of goods to the destination, including periods of visual observation and hovering. For insulin transportation, maintaining a temperature of 2-8 \({}^{\circ}\)C is desirable. The simple portable refrigerator box was maintained at room temperature during summer. However, insulin can normally still be used within a few weeks as long as the storage temperature remains below 30 \({}^{\circ}\)C [17]. Japan ranks fourth among countries facing the greatest threat from natural disasters [18]. Thus, it is necessary to consider the transportation of medical supplies during emergency situations in a large-scale disaster. Snow damage is also considered a major natural disaster in Japan. Sudden and heavy snowfall can make it difficult for blood transfusion vehicles to proceed, thus making it difficult to transport blood across a distance in locations that can be observed with the naked eye [19]. UAVs can be particularly useful when low temperatures prevail outside; in addition, it is desirable to maintain a temperature range of 4-6 \({}^{\circ}\)C for blood transportation. We achieved a temperature of \(-\)8 \({}^{\circ}\)C for outside conditions and ensured that blood could still be transported in environments with lower temperatures. This finding also applies to the transportation of emergency relief supplies to ships that may find berthing difficult because of an infectious disease outbreak and in instances of bridge failures during a disaster, among others. We believe that the original UAVs can be used for transporting goods to areas less than one sight distance away. Helicopter emergency medicine (HEM) vehicles, which are used for air medical treatment, are operated by air traffic control units. In contrast, UAVs are prohibited from flying in designated areas of the Ministry of Land, Infrastructure, Transport, and Tourism (e.g., airports), as well as in areas that are more than 150 m above land or a water surface. Furthermore, without a permit, UAVs cannot fly in densely populated areas in Japan [20]. UAVs and HEMs must usually operate in different flight zones; however, UAVs can be an interference while operating HEMs. In fact, there were reports of near misses involving UAVs and HEMs in 2016 [21; 22]. We believe that in future HEM emergencies, goods transportation by UAV from a landing site could be a new key element in many emergency phases. At the 2019 symposium of the Japan Aeromedical Society, HEM and UAV collaborations were identified as desirable because information  
Figure 1: The UAV transports the DMAT rucksack and the AED. (**a,b**) The UAV transported the disaster medical assistance team (DMAT) rucksack on June 29, 2019 (M1000; Mazex Co. Ltd., Osaka, Japan) (maximum take-off weight: 32 kg; maximum speed: 58 km/h) and transported the rucksack containing DMAT equipment (load weight: 17 kg) by manual control under visual flight conditions with auxiliary support. (**c,d**) UAV-assisted transport of an automated external defibrillator (AED) on 4 April 2020 (M1000; Nihon Kohden Corp., Tokyo, Japan) (load weight: 3.7 kg; size: \(44\times 26\times 10\) cm) by manual control under visual flight conditions with auxiliary support. collection by UAVs in the field could provide valuable information for HEM operations and flights. However, obtaining external information and collecting information from UAVs involves issues such as maintaining stable communication. Moreover, during a large-scale disaster, satellite communication is the only way of maintaining contact; however, even if one is able to use a satellite phone, a large earthquake could cause problems related to satellite phone congestion and data transmission speeds [23]. Given these issues, the use of UAVs under visual flight conditions may be the most promising first approach for UAV use in disasters (especially in large-scale natural disasters).