A novel integrated planning and guidance concept has been developed that optimizes aircraft trajectories from top of descent to the runway threshold to achieve a continuous engine-idle descent. The new concept, named time and energy managed operations, aims at reducing noise, gaseous emissions, and fuel burn while maintaining airport landing capacity by means of time management. Time and energy managed operations uses an optimization algorithm to minimize thrust and speed brake use through energy management by exchanging kinetic and potential energy. Sustained deviations during descent are corrected using a strategic or tactical approach. Time and energy managed operations is evaluated in a batch simulation study for various disturbances to test its robustness to disturbances and time constraints. Moreover, two different methods of correcting deviations are compared. Results show that time and energy managed operations allows idle descents while adhering to time constraints and can cope with disturbances and updated time constraints. Large wind estimation errors degrade time and energy managed operations performance.