Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001. / Includes bibliographical references (p. 199-203). / In order to support the development of improved methods for departure operations, the flow constraints and their causalities --primarily responsible for inefficiencies and delays-- need to be identified. This thesis is an effort to identify such flow constraints and gain a deep understanding of the departure process underlying dynamics based on field observations and analysis conducted at Boston Logan International Airport. It was observed that the departure process forms a complex interactive queuing system and is highly controlled by the air traffic controllers. Therefore, Flow constraints were identified with airport resources (runways, taxiways, ramp and gates) and with air traffic controllers due to their workload and control strategies. While departure delays were observed in all airport components, flow constraints manifested mainly at the runway system, where the longest delays and queues concentrated. Major delays and inefficiencies were also observed due to flow constraints at National Air Space locations downstream of the airport, which propagate back and block the departure flow from the airport. The air traffic controllers' main strategies in managing the traffic and dealing with the flow constraints were also identified. / (cont.) Based on these observations, a core departure process abstraction was posed consisting of a queuing element (representing the delays) and a control element (representing the air traffic controller actions). The control element represents blocking the aircraft flow, to maintain safe airport operation according to Air Traffic Control procedures and to regulate the outbound flow to constrained downstream resources. Based on this physical abstraction, an analytical queuing framework was developed and used to analyze the departure process dynamics under three different scenarios: the overall process between pushback and takeoff, departure sub-processes between controller/pilot communication events and under downstream restrictions. Passing which results mainly from aircraft sequencing and their suspension under special circumstances (such as downstream restrictions) was used as a manifestation of the control behavior. It was observed that Logan Airport exhibits high uncertainty and limited sequencing, hindering the air traffic controllers' ability to efficiently manage the traffic and comply with restrictions. In conclusion, implications for improved methods for departure operations are inferred from the observations and analysis. / by Husni Rifat Idris. / Ph.D.