Ground Based Augmentation System - Benefits
The FAA is developing GBAS to expand upon the capabilities afforded by satellite navigation. Specifically, GBAS offers benefits in the areas of capacity, efficiency, user benefits, and airport/surrounding community benefits.
GBAS will support complex procedures and terminal area paths that will compress the density of terminal operations without impacting safety, thus increasing capacity. It will de-conflict airspace through extended PVT ranges, reduce aircraft separation requirements and obstacle clearance requirements through more precise ground track paths. GBAS will provide the ability to change or create approach procedures without infrastructure changes, and also provide the ability to implement multiple, segmented, or variable glide slopes. In addition, a single GBAS system supports approaches at multiple runway ends, which will eliminate critical areas.
The efficiency benefits of the GBAS system include reduced air traffic controller workloads through reduced communications and radar vectoring. Other efficiency benefits include reduced time and distance in the terminal area, leading to fuel savings which is a huge cost savings to operators. The GBAS will allow for an increase in IFR availability, complex rollouts, and extended arrival procedures (50-160nm).
GBAS terminal area path (TAP) procedures will be uplinked to the aircraft, which eliminates the need for an in-aircraft procedure database. In addition, GBAS will eventually support low-powered continuous descent arrivals.
Uplinking the GBAS TAP procedures ahead of time allows the aircrew additional time to prepare the aircraft for landing and do it all in an optimal sequence will be truly beneficial to end users. Exacting aircraft locations and approximate times of arrival at key points along the TAP are critical to improving their operations in the terminal area and offer the user significant benefits.
Airport and Community Benefits
While many airports seek to expand their facilities and operations to serve current and expected future demand for air travel, the communities surrounding airports also continue to expand, filling previously unused land in the vicinity of the airports. One result is a growing concern about aviation related noise and its impact on these communities. Airlines and airframe manufacturers have worked together to significantly reduce the noise produced by modern aircraft, but noise generation remains a problem for many airports. More precise navigation offered by GBAS in the terminal area may provide an opportunity to greatly reduce the impact of aviation related noise by restricting aircraft to defined three dimensional routes designed to reduce the noise effects. Through the flexibility offered by GBAS to construct complex, defined, highly repeatable flight paths that can be used during all weather conditions, the current costs associated with noise mitigation and noise abatement may be reduced.