FAA marks GPS approach milestone

More than 3,000 WAAS approaches published

February 9, 2012

A milestone for the nation's transition to satellite navigation was celebrated Feb. 9 in an FAA office in Silver Spring, Md.—and in cockpits equipped with WAAS around the country.

The FAA AeroNav Products division published a new cycle of charts, including, for the first time, more than 3,000 satellite-based approaches. A total of 3,026 localizer performance with vertical guidance (LPV) and localizer performance (LP) instrument approaches are now available to pilots, guiding them safely through the clouds without reference to outside visual references—or ground-based navaids.

The creation of satellite-based approaches is part of the transition to NextGen, the nationwide performance-based (satellite) navigation system. Each new approach is test-flown prior to publication in aircraft with specialized sensors that precisely measure glidepath and other data. FAA officials noted that the new procedures give IFR pilots access to many airports where no approaches existed before. The new procedures also help reduce fuel consumption and operating costs, creating shorter routes with continuous descent profiles.

Ted Urda, a WAAS surveys and procedures project engineer, explained the complexity of the task, an ongoing effort, with perhaps two thousand more approaches to come. Around 5,200 runways survived the initial survey screening, showing LPV or LP potential.

The final number remains unknown, because runways and approach areas must each be carefully surveyed, and then reviewed to determine if an LPV or LP is possible.

Urda said feasibility is based on many factors, including terrain, obstructions, airport traffic flow, nearby airports, and airport infrastructure such as approach lighting. Potential approaches determined unfeasible for LPV are set aside for LP consideration—a type of approach that lacks the vertical guidance available with LPV, which is similar to the guidance available from an ILS. Urda said there will be fewer new LPVs published as a result, and more LPs coming on line. Currently, about 2,800 runways have an LPV approach; LPs account for the balance of the 3,026 satellite-based approaches.

Jim Moore

Jim Moore | Online Associate Editor, AOPA

AOPA Online Associate Editor Jim Moore joined AOPA in 2011 and is an instrument-rated private pilot who enjoys competition aerobatics.