An investigation into air traffic control communications protocols

Abstract

Pilot-ATC communication plays a vital role in ensuring the safety of air transportation and it is important that the proper protocols are in place to minimise misunderstandings This project is focused on understanding the current communication protocols set by aviation regulatory authorities namely the Civil Aviation Authority of Singapore (CAAS) hand book, and the merits and limitations of a 3D radar display.

The hand book provides both information guidelines for different transmission purposes such when providing clearances and voice protocols to be followed during the transmission. The information guidelines affect the content of the message to be sent while the voice protocols affect the structure of how the message should be sent. The approved voice protocols were employed to analyse actual aviation events; a routine flight and the other an emergency. While the actual voice protocols for a routine flight conformed to the official ones, for emergency situations, such voice protocols were not complied with. Instead, general guidelines provided by the hand book were shown to provide crucial instructions according to the emergency.

Additionally, studies done on 3D display show improvements in ATC-pilot communication. Mental model errors are eliminated since 2D display only provides numerical data on altitude level. It also leads to a clearer interpretation of the situation at aircraft holding areas in the event of a delay to land and the landing phase of a flight and improved situational awareness which leads to quicker detection of potential conflicts. On top of that 3D display provides greater visualisation of the airspace without the need for a mental model of altitude differences between aircraft. However, the downsides include technical issues such as inaccuracy when downsizing the actual vast airspace into a smaller 3D display area and reduced resolution of objects further away which is one of the limitations of using 3D technology, time consuming user interaction interface that can be confusing. Results from studies also showed that performance is comparable for both 2D and 3D in areas such as situational awareness of terrain features, basic perceptual judgements and weather separation.