Method for avoiding aircraft terrain collisions

The method involves generating a number of flight paths based on the aircraft's current flight performance, whereby the totality of paths forms a hierarchical tree structure with paths joined by branching nodes, testing potential evasion flight paths for critical terrain proximity with access to terrain model data until a safe path is determined and outputting a warning with or without recommending a flight path based on the determined path. An Independent claim is also included for a device for implementing the above method.