In the flatlands that won’t matter, but in hill country I recommend that you not load an approach with vectors, even when being vectored onto the approach. Note that with some GPSs, loading an approach with vectors deletes all but the last few waypoints on the approach. Then set all frequencies including the one for weather at your destination.īefore loading the approach in the GPS, determine whether you’ll fly the approach using vectors, during which the controller issues a series of turns onto the approach, or via pilot navigation, where you fly the approach from a starting point without guidance from the controller. Verify that GPS is in the title of the approach and not RNP (required navigation performance), because those approaches cannot be flown with a WAAS-capable GPS. In Alaska, signal availability to fly to LPV minimums is significantly lower.Įn route, brief the approach by reviewing the chart. So, if you do arrive during one of those outages, you may want to get vectored around to try the approach again. But the good news is those outages are very short, usually no more than 15 seconds. Along the East and West Coasts of the contiguous 48 states, availability can be as low as 99 percent, meaning that for one out of every 100 attempts, you won’t be able to fly to LPV minimums. The current GPS availability for nonprecision approaches in the continental United States is more than 99.99 percent, meaning on average, if you check RAIM 10,000 times, you’ll fail to get RAIM only once!īut don’t be surprised if there’s insufficient signal quality to fly to LPV minimums. Incidentally, if you do a RAIM check and it fails, you may want to play the lottery. But RAIM can’t tell you if you’ll have sufficient signal quality to fly to LPV minimums, so there’s no need to check it if you plan to fly to LPV approach or LNAV/VNAV minimums. If flying in oceanic or remote areas, the FAA requires that you run an FDE prediction program, available from Garmin and other companies, to check GPS satellite coverage.Įn route, you can check RAIM if you’re planning to fly to LNAV minimums. You’ll also want to contact Flight Service for any WAAS notams. Your preparation before leaving the ground should include checking that your GPS database and charts are current - and if your charts are on an iPad, checking that the iPad is fully charged. Circling minimums permit you to circle to land on any runway, except those prohibited in the chart notes.įlying an approach to LPV minimums starts long before you reach the approach. They are the only straight-in GPS minimums that can be flown with a non-WAAS, approach-certified GPS. LNAV, or lateral navigation, mini-mums are used to fly a series of stair steps until you reach a minimum descent altitude (MDA). LP, or localizer performance, minimums are like a localizer approach the angular guidance narrows as you near the runway and there’s no vertical guidance. You can usually ignore the LNAV/VNAV minimums, since LPV minimums are almost always lower. Other minimum choices may include LNAV/VNAV, LP, LNAV and circling. LPV approach minimums, usually 200 or 250 feet agl, are typically the lowest available on a GPS approach. LPV stands for “localizer performance with vertical guidance,” meaning it’s similar in precision to the localizer and glideslope of an ILS approach. Technically there is no such thing as an “LPV approach.” Instead, LPV approach is just one of several minimum types that can be flown on a GPS approach with a WAAS-capable, instrument-certified GPS. So I did much of what you’ll read here comes from my Max Trescott’s GPS and WAAS Instrument Flying Handbook. That said, flying a GPS approach can be so complicated you could write a book about it. So flying a GPS approach to LPV minimums can be as simple as flying an ILS approach, but only if you’re extremely familiar with the GPS in your cockpit. Of course each GPS is different and the odds of successfully loading an approach on an unfamiliar GPS are slim. If you know how to operate a particular GPS model and can successfully load a GPS approach, flying an approach to LPV minimums can be as simple as flying an ILS approach. By dialing in the right frequency and keeping the needles centered, a pilot could successfully fly an approach even using radios he or she had never seen before. In the past, pilots had it easy when flying an ILS (instrument landing system) approach. One challenge for instrument pilots is that the rapid change in technology found elsewhere in our lives has invaded the cockpit.
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