SBAS is designed to enable users to rely on GNSS navigation data for all phases of flight, from en route through category I approach for all qualified airports within an SBAS coverage area.

SBAS provides a capability to conduct vertically guided approaches to non-instrumented runways, providing significant improvement to operational safety that was previously un-available.

SBAS is not sensitive to temperature fluctuations and has no barometric / temperature limitations. When using Barometric Vertical Navigation (BARO VNAV) a minimum temperature limitation is published for each procedure for which BARO-VNAV minimums are published. This temperature represents the airport temperature below which the use of BARO-VNAV is not authorized to the LNAV/VNAV DA. The pronounced effect of cold temperatures on BARO-VNAV operations means that the approach may not be flown at all using BARO-VNAV when the temperature is below -20� Celsius.

SBAS is an enabler for FAA Next Generation Transportation System (NEXTGEN) and European Single European Sky Air Traffic Management Research (SESAR).

SBAS provides benefits beyond aviation to all modes of transportation, including maritime, highways, and railroads.

Other benefits of an SBAS are:

En Route Capability 

SBAS operational criteria include integrity assurance and eliminate the need for GNSS avionics Receiver Autonomous Integrity Monitoring (RAIM) checks. This feature means that SBAS is considered a primary Navigation system. GNSS navigation alone requires RAIM checks and is considered a supplementary navigation system.

The very high resolution point-in-space of SBAS supports flexibility to design more efficient airspace and instrument procedures SBAS technology provides the opportunity to cover very large areas of airspace and areas formerly un-served by navigation aids and is an enabler of ICAO Performance Based Navigation (PBN). The ICAO PBN manual provides initiative for development of en route navigation guidance. Two key components of PBN are Area Navigation (RNAV) and RNP. Each includes lateral navigation standards for performance, functionality and capability. 

These standards allow the flexibility to design more efficient airspace and instrument procedures that collectively improve safety, access, capacity and efficiency. Direct routes minimize track dispersion and environmental impacts by reducing fuel use and pollution. 

By eliminating the need for airways to be tied to ground-based navigation aids, SBAS-equipped aircraft gain the flexibility and benefit of point-to-point operations. SBAS satisfies PBN based equipment requirements for the new, more direct en route flight options of ‘T’ and ‘Q’ routes.

  1. T-Route: an RNAV route used in low-altitude airspace operating below 18,000 feet.
  2. Q-Route: an RNAV route used in high-altitude airspace (18,000 feet ? 45,000 ��� feet).

Immediate, tangible benefits have been noted. Controller/pilot transmissions are reduced by over 30%. There is a significant reduction in track dispersion and the more efficient procedure designs reduce flight distances resulting in fuel savings for the operators. Learn more about T-routes, Q-routes, and LPVs at http://www.faa.gov/nextgen/flashmap/

Approach Capability 

SBAS provides the vertical guidance necessary for Localizer Precision Vertical Guidance (LPV) defined approaches. SBAS LPV-200 approaches are equivalent to Category I Instrument Landing System (ILS) approaches for runway ends qualified for Category I ILS. For non-qualifying runway ends, SBAS supports a Localizer Precision (LP) non-precision approach. These SBAS supported approaches do not require the installation and maintenance of any landing system navigation aids.

LPVs are operationally equivalent to a Category I Instrument Landing System (ILS), but are more economical. LPV specifications are developed within the definition of ICAO APV’s and add increased capability, flexibility, and in many cases, more cost-effective navigation options than legacy ground-based navigation aids. SBAS use will become increasingly more vital as older legacy equipment (such as NDB, VOR, or ILS) is decommissioned and taken out of service.

SBAS also provides for immunity to improper setting of QNH on the aircraft. Additionally, SBAS provides vertical guidance via GNSS constellation augmentation, SBAS supported.

Finally, SBAS provides for positive guidance (RNP 0.3) across the SBAS service volume.

Terminal 

SBAS supports Trajectory Based Operations (TBO) Continuous Descent Approach (CDA) supporting significant fuel savings for operators.

SBAS Terminal operations offer a significant reduction in track dispersions.

Select Faq Category: