LNAV is an approach specification, as is LNAV/VNAV, LP, and LPV. The minimum LNAV/VNAV DA permitted is 250 AGL and for the LPV is 200 AGL. For a LNAV/VNAV, it has two surfaces that are evaluated for obstacle penetration, a sloping one to a point approximately 4000 feet from the threshold and from that point a level surface that is 250 feet above the highest obstacle to the threshold. For an LPV, obstacles must not penetrate a sloping surface that continues down close to the threshold. However, if obstacles are not an issue, the LPV specification normally allows for a lower DA. The specifications for the two types of APV procedures are different and sometimes produce backwards results, particularly when there are obstacles close in to the runway or in the missed approach segment. The DA on the LNAV/VNAV is generally higher than the DA on a LPV, but not always. The +V should not be used below the MDA as there is no assurance of obstacle or terrain clearance from the MDA to the runway. The +V is a feature provided solely by the manufacturer of the vertical guidance equipment to aid the pilot in establishing a constant angle descent from the FAF to the MDA. You will never see it charted on an approach chart. The LNAV+V advisory glideslope is not a part of the LNAV procedure. A Baro-VNAV approach certified and equipped aircraft may fly a LNAV/VNAV procedure, so can most aircraft equipped with a WAAS GPS unit. Baro-VNAV is a technology, LNAV/VNAV is an approach specification and is an APV (Approach with Vertical). The use of Baro-VNAV as an approach type in the question is not very precise. How the missed approach point is determined is different for different types of approaches, but by definition, each approach procedure has a missed approach point. For a non vertically guided procedure, this is at a fix or a specified location along the final approach course. MISSED APPROACH POINT− A point prescribed in each instrument approach procedure at which a missed approach procedure shall be executed if the required visual reference does not exist.įor a vertically guided procedure, this is at the point on the GS where the aircraft reaches the DA.
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