Whereas for LPV approach the vertical guidance is derived by GPS a LNAV/VNAV approach the vertical guidance is based on barometric. It will be APV if there is vertical guidance, if there isn’t it will be NPA.Īn LPV due to several differences in both lateral and vertical guidance can have minimums as low as 200 ft, so it is categorized as a CAT I. I believe from the pilot point of view I can offer another explanation to this subject.Īny approach under PANS-OPS as RNAV – GPS/GNSS or under TERPS as RNAV (GPS) will either be NPA (non precision approach) or APV (approach procedure with vertical guidance) dependent if the approach has vertical guidance or not. But leave the EU it has, which means leaving all EU related programs including EGNOS (even though the UK’s NATS was one of the founders of EGNOS…)Īnyway, the EGNOS working agreements are not going to be renewed, so as of 25 June 2021, the UK will not longer participate in the EGNOS program and their LPV approaches will no longer have the accuracy assurance that EGNOS provided. Not to be confused with Europe the continent – the UK is still part of that. Brexit means the leaving of the UK from the EU. So EGNOS is what gives LPVs their precision. In fact, it has 95% accuracy, which translates into the locating of a position to 1-3 meters horizontal accuracy, and between 2-4 meters vertical accuracy. It is basically a bunch of European satellites, (actually just 3 out of the Galileo GNSS system, and a network of 30 referencing stations), that improves positioning measurements and gives much better accuracy than GPS alone. Not to be confused with the delicious Christmassy drink, EGNOS stands for ‘European Geostationary Navigation Overlay Service’. The LPV minima is the same as the ILS Cat I minima Okay, so what is EGNOS? ![]() An ILS needs a whole bunch of ground and plane equipment meaning there is a lot more that can fail on us. They also use GPS, so the equipment you need is on your plane. Well, because they get us nice and low so we can see the runway in not so nice weather. Secondly, if you’re planning on using an airport without an ILS or some sort of ground based navaid as your alternate, then the FAA wants you to plan on LNAV minimas. There are a few things you also need to know – first up, you need a special receiver on your plane for it (which is probably why a lot of folk are scratching their chins and wondering what on earth as LPV is). And just like an ILS, they get more sensitive the closer to the runway you get, which is what allows you to operate down to lower minimas than, say, your less sensitive LNAV option. They provide lateral and guidance down to a DA, just like an ILS. What uses what and where That’s the basics, but how does it actually work? SBAS stands for satelitte-based augmentation system, and is a generic term for the use of geostationary satellites which broadcast augmenting information. You might also see the term SBAS used in the same breath. So an LPV is an APV? Yes, and the point of this distinction is that it’s a lot cheaper, quicker and easier to implement than an ILS because there is a lot less paperwork involved, but it still offers “nearly” the same precision as an ILS – meaning you get down low if you need to. Instead, it is classified as an ‘approach with vertical guidance’, or APV for short. It is a GPS based approach sort of like LNAV/VNAV but also, confusingly, sort of like an ILS.Īn LPV has vertical guidance but is not a precision approach (which your standard ILS of course is). ![]() LPV means localizer performance with vertical guidance. If you do fly these, and fly them in the UK, then read on. If you read this and are thinking “That isn’t something I’ve ever flown” then you can probably stop reading (unless you’re interested in a bit of aviation geekery), because this probably won’t have much of an impact on you. What exactly are they? What on earth is EGNOS? And what has Brexit got to do with all of this? What is an LPV approach? This means their access to EGNOS will stop – which means LPV approaches at UK airports will no longer be possible. On June 25 the UK’s current EGNOS working agreement comes to an end, and they are not renewing it.
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