This paper examines the application of intelligent cockpit systems to aid pilots at the task of generating (and then following) a safe four dimensional trajectory to the runway threshold during emergencies. A proof-of-concept system is described, including the use of embedded fast-time simulation to predict the trajectory defined by a series of discrete actions, and the pilot interface. Then, the results of a flight simulator evaluation with airline pilots are detailed. The inability of pilots to fully realize the consequences of their planned actions in very aggressive maneuvers indicates a need for cockpit aids. However, results also suggest that, for the use of the tool to be operationally feasible, it must be capable of suggesting safe trajectories to the pilot; one version of the system that only verified plans entered by the pilot was found to have significantly detrimental effects on performance and on pilot workload. Results also highlight that the trajectories suggested by the system must capture the context of the emergency; for example, in some emergencies pilots were found willing to violate flight envelope limits to reduce time in flight - in other emergencies the opposite was found. This paper then concludes with recommendations for future cockpit systems.