US Patent 7937191 Termination secured route planning

A method of forming a safe termination operation volume, and an aircraft provided with a system using such a volume to plan a flight route and/or an emergency route. The volume indicates the lowest allowable flight altitude to achieve a glide path of a vehicle to a termination point of an area of interest, wherein non allowable fly zones are taken into consideration by adding flight altitude to come around the non allowable fly zones when calculating the lowest allowable flight altitude.