China Initial 4D Flight Trial Evaluation

In order to improve air traffic operational safety and efficiency in China, Civil Aviation Administration of China (CAAC) and Ministry of Science and Technology (MOST) of China launched the project of Initial Four-Dimensional (I4D) flight trial in 2015. The project aims to evaluate the I4D operational concept and the performance of the technical enablers. The flight trial was performed on 20th March 2019. An A320 aircraft equipped with I4D avionics flew between Tianjin Binhai International Airport (ZBTJ) and Guangzhou Baiyun International Airport (ZGGG). In this paper, the performance of flight trial was evaluated, including Aeronautical Telecommunication Network (ATN) performance, Automatic Dependent Surveillance-Contract Extended Projected Profile (ADS-C EPP) performance, Controller Pilot Data Link Communications (CPDLC) service performance, Controlled Time of Arrival (CTA) operations. The evaluation shows I4D offers safety gains with better air and ground trajectory information sharing. The efficiency of Air Traffic Management (ATM) system can be improved as the flight time of arrival is more predictable and precisely controllable. Meanwhile, these changes in operation can reduce both pilot and controller workload by using CPDLCC/ADS-C. Specifically, 62.7% of the regular communication time can be saved. Besides, Top of Descent (TOD) changes during the progress of CTA operations, thus, its information is necessary to help controllers. In addition, some suggestions are derived from this trial. The analyses and evaluation in this paper will help shed light on policies development of I4D implementation.