Determining landing sites for aircraft

A routing tool for generating safe ingress flight paths to an identified landing site for an aircraft, the routing tool comprising a database configured to store flight data corresponding to a flight path for the aircraft, and a routing module configured to:

• generate a spanning tree for the identified landing site by
• producing a plurality of possible approach paths by starting at a touchdown point on the identified landing site and building each of the plurality of possible approach paths from the touchdown point outward while minimizing altitude changes while moving away from the touchdown point,
• identifying obstructions proximate the identified landing site, and
• eliminating any obstructed possible approach paths of the plurality of possible approach paths that conflict with the obstructions to produce a plurality of allowed approach paths to the touchdown point;
• store, in a data storage device, the spanning tree including the allowed approach paths;
• provide information from the spanning tree in the data storage device to an in-flight display for use by aircraft personnel;
• and
• provide a countdown timer with each of the plurality of allowed approach paths indicating a time in which the allowed approach path remains available as an option for the identified landing site.

A non-transitory computer readable storage medium having computer executable instructions stored thereon, the execution of which by a processor cause a routing tool to:

• generate a spanning tree for an identified landing site by
• producing a plurality of possible approach flight paths by starting at a touchdown point on the identified landing site and building each of the plurality of possible approach paths from the touchdown point outward while minimizing altitude changes while moving away from the touchdown point,
• identifying obstructions proximate the identified landing site, and
• eliminating any obstructed possible approach paths of the plurality of possible approach paths that conflict with the obstructions to produce a plurality of allowed approach paths to the touchdown point;
• store, in a data storage device, the spanning tree including the allowed approach paths;
• provide information from the spanning tree in the data storage device to an in-flight display for use by aircraft personnel;
• display a vertical profile view of a glide path for approach to the identified at least one landing site that includes current aircraft position;
• and providing a countdown timer with each of the plurality of allowed approach paths indicating a time in which the allowed approach path remains available as an option for the identified landing site.