New Planned GPS Outages Raise Major Concerns

The FAA has announced its plan to disrupt GPS navigation signals over a large section of Southern California centered at a spot 19 miles northeast of the Palmdale VOR. The outage will affect GPS, WAAS, GBAS and ADS-B. The area of outage depends on altitude. At 50 feet AGL (lower than we typically flight plan for), the outage will have a radius of just over 90 nm, going to an almost 200-nm radius at FL 250.

The tests, which are slated to run on May 4th and May 11th, and from May 14th through May 17th, are said to be for "GPS Testing" purposes, though what those purposes are is not known. The NOTAM includes our favorite NOTAM language that the NOTAM might change, so check for new NOTAMS, which we assume might change, too. And so on.

In any case, make backup plans. If you're flying with VOR as your backup, dust off those skills and get at it. And remember, your RNAV approaches are almost exclusively GPS reliant, so make other plans if you need to make an approach during periods of testing. VOR, ILS and DME signals will be unaffected. And you can always ask for vectors, which ATC might just give you before you ask. Here's the text of the short, not-so-sweet NOTAM.