![]() ![]() Requires a WAAS receiver in the airplane and can have minimums as low as 200 feet agl and half-mile visibility with proper approach and runway lighting. LPV (Localizer Performance with Vertical guidance) - Offers the lowest minimums of all GPS approaches but are technically still considered nonprecision approaches (i.e., APproach with Vertical guidance - APV). The advisory glideslope does not always ensure obstacle clearance. However, it may appear when you load the approach if the GPS is compatible. Pilots must use the barometric altimeter to meet all altitude restrictions. LNAV+V is not the same as LNAV/VNAV or LPV. If you see LNAV+V displayed on your WAAS unit’s annunciator, you may fly the glideslope to the LNAV MDA. LNAV+V - LNAV approach plus advisory Vertical guidance. Some LNAV/VNAV minimums are higher than LNAV minimums. Pilots must adhere to temperature limitations unless employing temperature compensation under an authorization from ATC. Example: Baro-VNAV NA below negative 15 degrees Celsius (5 degrees Fahrenheit) or above 47 degrees Celsius (117 degrees Fahrenheit). Decision altitude is the altitude at which you’re supposed to look out the window and contemplate if you’re going to land or go around - while you continue to descend - rather quickly! If your airplane depends on baro-VNAV (barometric Vertical NAVigation) instead of WAAS for VNAV, you may be restricted by temperature from using the (sometimes) lower VNAV minimums. LNAV/VNAV approaches are flown to a decision altitude rather than MDA. Vertical guidance is provided either by WAAS or approach-certified baro-VNAV systems. Lateral sensitivity does not increase as the aircraft gets closer to the runway. LNAV/VNAV, aka L/VNAV (Lateral NAVigation/Vertical NAVigation) - Horizontal and approved vertical guidance to the LNAV/VNAV line of minimums. For example, baro-VNAV, LDA with glidepath, LNAV/VNAV and LPV are APV approaches. LP minimums are published only if they provide lower minimums than LNAV.ĪPV (APproach with Vertical Guidance) - An instrument approach based on a navigation system that is not required to meet the precision approach standards of ICAO Annex 10 but provides course and glidepath deviation information. Older WAAS receivers may not contain LP capability unless the receiver has been upgraded. LP is the GPS equivalent of a localizer approach. LP will not be published with lines of minimums that contain approved vertical guidance (i.e., LNAV/VNAV or LPV). LP is not a fail-down mode for LPV - LP and LPV are independent. Lateral sensitivity increases as the aircraft gets closer to the runway (or point in space for helicopters). Typically use barometric altimeter data for descent to MDA. Lateral-only WAAS guidance found at locations where terrain or obstructions prevent vertically guided LPV procedures. LP (Localizer Performance) - Nonprecision WAAS-mandatory approach. When the aircraft reaches the final approach fix, the pilot descends to a minimum descent altitude (MDA) using the onboard barometric altimeter (aka “dive and drive”). ![]() Pilots may use a WAAS-enabled GPS for LNAV, but WAAS is not mandatory. LNAV (Lateral NAVigation) (aka GPS NPA) - A nonprecision approach that uses GPS and/or WAAS for LNAV. Check the chart notes (e.g., DME/DME RNP-0.3 NA). Certain RNAV (GPS) approaches are not available to these type units as the airplane could be beyond the service volume of a necessary DME facility. Some RNAV units use DME cross referencing (DME/DME) to achieve RNP 0.3. ![]() All IFR-certified GPS units meet 0.3 RNP. Virtually all GPS approaches require an RNP (Required Navigational Performance) of 0.3, which means an aircraft tracking the final approach course with a centered needle can be expected to be within 0.3 nm of the centerline 95 percent of the time. RNAV GPS (aRea NAVigation) stand-alone instrument approaches have become commonplace as GPS and the Wide Area Augmentation System (WAAS) hit the mainstream. ![]()
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