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The next implementation of GPS procedures were no longer dependant on the NAVAID position and
coverage. This major improvement provides instrument approaches to airports that didn't
have ground-based NAVAID coverage. These approaches were initially published in the GPS
RWY XX format. However, in 2000 a new approach chart format was adopted by the FAA and GPS
approaches began to be published in the RNAV (GPS) RWY XX format, using the lateral
navigation (LNAV) minima line. (Note: All GPS non-precision approaches are considered
to be LNAVs, regardless of the publication format.)
Containment
Increased precision in position determination and course guidance resulted in a smaller OEA.
Additionally, the plan view of the stand-alone GPS procedures uses a "T" design
to develop more standardized final and missed approach fix location based on RNAV criteria.
Alerting
GPS stand-alone approach availability and signal outages are determined by RAIM.
GPS stand-alone approaches greatly increased the number of locations which could have
instrument approaches. As with the overlay approaches, if the IFR flight plan requires an
alternate, the pilot must flight plan to use an approved operational instrument approach
procedure (other than GPS) that the aircraft is equipped to fly.
Pilots flying GPS approaches can descend to the straight-in (S-runway number) Minimum
Descent Altitude (MDA) for their approach category on GPS RWY XX approaches or the LNAV MDA
on RNAV (GPS) RWY XX approaches. There are approximately 4,000 GPS (LNAV) approach
procedures as of May 2006.
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