An efficient, reliable and futuristic Air Transportation System (ATS) is the key to handle the anticipated rapid changes in the aviation industry over the next few decades. Trajectory Based Operations (TBO) could be considered as one of the most significant solutions to cater for these problems. This paper discusses the development of a 4D optimal flight trajectory based on aircraft performance, weather forecasts, Air Traffic Control (ATC) database and aircraft operational data. Dynamic Programming is utilized in the optimization process for its qualities of avoiding iterative calculations, predicting the required amount of calculations and feasibility of applying inequality constraint conditions. Optimal flight trajectories were generated for a single aircraft for its climb, cruise and descent phases in a provided 4D grid platform based on a busy domestic flight route, between Tokyo (Haneda) and Fukuoka. Flight data were recorded on a commercial GPS data logger inside an airliner cabin and used to compare with optimum solutions obtained from the model. Consumed fuel consumption and flight time were evaluated to understand the benefits gained by the optimization.