Reachability analysis of landing sites for forced landing of a UAS in wind using trochoidal turn paths

This paper details a method to ascertain the reachability of known emergency landing sites for any fixed wing aircraft in a forced landing due to engine failure in steady uniform wind conditions. With knowledge of the aircraft´s state and parameters, and landing site location and landing direction, the minimum height loss path can be defined. This uses glide performance calculations and a trajectory planner to give a minimum height loss to each landing site. Based on the aircraft´s initial altitude it can calculate if the site is reachable, and how reachable it is. The path definition takes into account wind and uses a geometric shape called a trochoid to define the gliding turns in wind. This method is generic enough for use by any aircraft in any wind conditions.