Preliminary design of a low speed, long endurance remote piloted vehicles (RPV) for civil applications

The present paper describes the major features of an unmanned air vehicle, designed under very severe safety and performance requirements for missions of surveillance of borders and coasts, fire detection, and search and rescue. Because of safety reasons, two engines are mandatory for the aircraft. Additionally, the mission requirements can be translated into initial specifications in the following terms: payload not less than 42 kg, cruise speed between 120 and 150 km/h, maximum speed higher than 200 km/h, cruise altitude of 3000 m, service ceiling higher than 4000 m, autonomy around 15 h, gliding distance covered after full engine failure greater than 100 km, and conventional take-off and landing in short unprepared runways. The design covers all common areas: configuration and sizing, aerodynamics, performance, stability and control, airworthiness, and initial structural design. Following suggestions from scholars and authorities, and taking into account the peculiar operational conditions of the vehicle, JAR 22 (Powered sailplanes, Utility category) are used as the basis for airworthiness certification.