LPV Explanation - II
These documents explain LPV Approaches. This is part 2/3.
LPV - Localizer Performance with Vertical Guidance
LPV approaches are based on WAAS/GPS and are very similar to an ILS approach, especially when it comes to the MDA/MDH. However they are at the present time not considered precision approaches, which is due to the fact that they meet the ICAO/FAA precision approach criteria.
LPV approaches have a lateral and vertical guidance down to a MDA/MDH or DA/DH. And like an ILS the LPV has an angular guidance setup which means the guidance becomes more sensitive the closer you get to the runway. Although at the threshold it then becomes linear. That way the minimum of a LPV can be as low as a CAT 1 ILS approach!
So how does the LPV approach differ from the RNAV approach with LNAV/VNAV guidance?
It comes mainly down to the fact that the LNAV/VNAV approaches don't have an increasing angular guidance when getting closer to the runway. So they are just like a standard LNAV approach with a 0.3 NM corridor left and right of the centerline, from the Final Approach Fix/Point down to the Missed Approach Point. Also the vertical guidance is linear and not angular like in the LPV approaches. So the area that needs to be considered for obstacles clearance is greater which then filters down to a higher MDA/MDH/DA/DH for the LNAV/VNAV approaches.
Only for Flight-Simulation!