October 28, 2012 Leave a comment
The agency intends to publish another 2,500 procedures by 2016, which will allow every runway in the nation that qualifies for an LPV to have one.
The latest data available from FAA, as of September 20, 2012, show the total number of approaches with LPV minimums has reached 2,989. By comparison, there were 1,281 category 1 ILS approaches in the inventory as of that date. More than 50 percent of the so-called LPV approaches serve airports that have no approaches that rely on ground-based navigation aids (i.e., ILS, localizer, VOR, or NDB). LPV procedures truly are expanding the options for instrument-rated pilots who fly aircraft equipped with IFR-approved, WAAS-capable GPS navigators.
LPV approaches can serve runways that may not meet the requirements for an ILS–indeed, many of those runways are suitable only for small general aviation aircraft. To learn about some of the criteria, see Table A16-1B Airport Infrastructure (from AC 150/5300) below. For example, the minimum runway length for an LPV approach is 3200 feet; the comparable number for an ILS is 4200 feet.
Now, the minimums for an LPV approach to a 3200-ft runway are at least 1 statute mile visibility and a DA of 350-400 feet. If an LPV procedure is to match the best minimums for a typical ILS (1/2 statute mile visibility and a DA of 200 feet), the LPV procedure must be to a runway that meets criteria for a conventional precision approach, including runway length, lighting, parallel taxiways, and markings.
Of course, an LPV procedure is essentially just data in a GPS navigator. To establish an LPV procedures, the owners of an airport don’t have to invest in or maintain ILS transmitters. Once the FAA has the required obstacle surveys and gathered related information, publishing LPV procedures to both ends of an eligible runway (indeed, to the ends of all eligible runways at an airport) requires little incremental investment (for example, to cover the costs of designing and flight-testing each additional procedure). That’s the main reason that the FAA can publish so many new LPV procedures and plan to meet the goal, in four years, of making LPV approaches available to all eligible runways.