RNP is here!

Exciting news this morning: My airline has become only the 2nd airline in the US (behind Big Sister) to receive FAA approval to conduct RNP approaches. RNP stands for Required Navigational Performance; to get approval for RNP approaches, you need to demonstrate the ability to remain with .3 miles of the final approach course & missed approach course under the worst possible conditions - including GPS sensor failure on the approach. The UNS1E flight management system on the MegaWhacker uses DME triangulation and inertial data as backup in case of loss of GPS signal.

From an operational standpoint, an RNP approach is very similar to a GPS approach - we use virtually the same procedures for planning and executing the approach. One major difference is that you can fly curved courses with RNP, even inside the final approach course or on missed approach. This, plus the redundancy that RNP guarantees, allows for much lower minimums than GPS (or other non-precision) approaches to airports with significant terrain. At Palm Springs, for example, the current approach gets us down to 1823 feet above airport elevation and requires 3 miles visibility; the RNP 31L approach will get us to 304 feet with 1 mile visibility.

My airline says it has been working on RNP for around nine years, with very intensive testing and certification work over the last two years. This is a pretty big milestone, then - one with the potential to revolutionize our operations at airports with challenging terrain, like Sun Valley, Palm Springs, or Mammoth Lakes. Oh wait, did I let that last one slip? Heh, it's wishful thinking but feel free to start a rumor...