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Lpv vs lnav vs rnav12/19/2023 ![]() ![]() The RNAV chart includes information formatted for quick reference by the pilot or flight crew at the top of the chart. ATC clearance for the RNAV procedure authorizes a properly certified pilot to utilize any minimums for which the aircraft is certified (for example, a WAAS equipped aircraft utilizes the LPV or LP minima but a GPS only aircraft may not). GBAS procedures are published on a separate chart and the GLS minima line is to be used only for GBAS. LP will be published in locations where vertically guided minima cannot be provided due to terrain and obstacles and therefore, no LPV or LNAV/VNAV minima will be published. A new type of nonprecision WAAS minima will also be published on this chart and titled LP (localizer performance). The original GPS minima, titled “S-XX,” for straight in runway XX, is retitled LNAV (lateral navigation). LPV and LNAV/VNAV are both APV procedures as described in paragraph 5-4-5 a 7. LNAV/VNAV was added to support both WAAS electronic vertical guidance and Barometric VNAV. The GLS minima line has now been replaced by the WAAS LPV (Localizer Performance with Vertical Guidance) minima on most RNAV (GPS) charts. Ground Based Augmentation System (GBAS) Landing System (GLS) was a placeholder for future WAAS and LAAS minima, and the minima was always listed as N/A. The reformatted approach chart is titled “RNAV (GPS) RWY XX.” Up to four lines of minima are included on these charts. One reason for the revision is the addition of WAAS based minima to the approach chart. The original stand alone GPS charts, titled simply “GPS,” are being converted to the newer format as the procedures are revised. This format avoids unnecessary duplication and proliferation of instrument approach charts. When using baro-VNAV guidance, the pilots should check for any published temperature limitations on the approach chart which may result in approach restrictions. The specified vertical path is typically computed between two waypoints or an angle from a single way point. Barometric Vertical Navigation (Baro-VNAV)īaro-VNAV uses barometric altitude information from the aircraft’s pitot-static system and air data computer to compute vertical guidance for the pilot. Baro-aiding satisfies the Receiver Autonomous Integrity Monitoring (RAIM) requirement in lieu of a fifth satellite. The current altimeter setting may need to be entered into the receiver as described in the operating manual. Baro-aiding requires four satellites and a barometric altimeter input to detect an integrity anomaly. ![]() the aircraft pitot-static system) to provide vertical reference and reduces the number of required satellites from five to four. Pilots must use the barometric altimeter in a similar fashion for ILS, LPV, and LNAV/VNAV minima.īarometric aiding is an integrity augmentation that allows a GPS system to use a non-satellite input source (e.g. Today, LNAV/VNAV minima may be flown using approved WAAS equipment. ![]() At that time, only aircraft equipped with a flight management system (FMS) and certified baro-VNAV systems could use the LNAV/VNAV minimums. Approved vertical guidance is available on LNAV/VNAV minima and existed before the WAAS system was certified. WAAS vertical guidance can support LPV minima as low as 200 feet AGL. Advisory vertical guidance is not required and is an optional capability.Īpproved vertical guidance provides operational benefit permitting the use of the LPV, LNAV/VNAV and ILS lines of minima. Pilots must use the barometric altimeter as the primary altitude reference to meet all altitude restrictions. LNAV+V is not the same as LNAV/VNAV or LPV. The intent is to aid the pilot in flying constant descent to the MDA. The system includes an artificially created advisory glide path from the final approach fix to the touchdown point on the runway. The manufacturer should use a notation to distinguish advisory vertical guidance (e.g. Depending on the manufacturer, WAAS-enabled GPS units might provide advisory vertical guidance in association with LP or LNAV minima. ![]()
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