What program assigns departure times to facilitate integration into the en route traffic stream?

The En Route Sequencing Program is specifically designed to assign departure times to aircraft, ensuring they can be effectively integrated into the ongoing en route traffic. This program plays a crucial role in managing air traffic flow, optimizing the sequence in which aircraft depart and ensuring that they can join the main traffic stream in an orderly manner. By providing departure times, the program helps reduce congestion and delays, as air traffic controllers can better plan for arrivals and departures in a busy airspace.

In contrast, while the Traffic Management Unit oversees overall air traffic management and can contribute to the flow of traffic, it does not specifically assign departure times in the same targeted manner as the En Route Sequencing Program. The Air Traffic Control System encompasses the entire framework of air traffic management, but the focus of the question is on the specific program dedicated to sequencing departures. Lastly, Flight Data Management primarily deals with the handling and processing of flight data, rather than actively assigning times for departures. This is why the En Route Sequencing Program stands out as the correct answer.