Integration of the ground-based augmentation system in continuous descent operations

Predictability is a necessity in today's commercial flight operations if delays are to be minimized. Possible mitigations, such as the implementation of continuous descent arrivals (CDAs), may help generate the required procedural predictability to curtail these delays. However, on the basis of its individual avionics suite, each aircraft follows a different barometric vertical descent path; furthermore, the aircraft may be given additional level-off segments by air traffic control to compensate for possible deviations in the vertical profile. Therefore, aircraft flying the current descent profiles are too unpredictable and thus the procedures cannot be implemented in complex airspace structures or when traffic is moderate to high. This study introduces a mitigation to this problem by taking the global positioning system (GPS) one step further by integrating the GPS-based ground-based augmentation system (GBAS) into the new optimized continuous decent arrival procedure, subsequently, allowing for the introduction of a geometrical vertical guidance, namely, the GBASCDA, which will make the aircraft flying the descent profile predictable. With the increase in availability of GBAS aircraft equipage, specifically the GPS landing system (GLS), and the approaching amendment of the Appendix E of the Minimum Operational Performance Standards for GPS Local Area Augmentation System Airborne Equipment–RTCA DO-253D, this idea of the integration of the GBAS on the arrival/descent segment as a viable solution may be finally coming within reach.