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A 3D approach consists of a ILS, RNAV with glide path guidance (LNAV/VNAV), RNAV LPV.
1) Does the LNAV/VNAV and LPV uses WAAS?
2) Is WAAS part of TSO C-145 GPS/GNSS receiver onwards? Or is WAAS also included in C-129?
3) Since both LNAV/VNAV and LPV gives you a glideslope guidance with azimuth, do they belong to the category of a precision approach as well or would it be a non precision approach?
4) Do you use DA or MDA for a LNAV/VNAV and LPV
The AIP defines a precision approach as
"An instrument approach procedure utilising lateral and vertical guidance provided by an ILS or GLS". AIP GEN page 22.
It also defines Decision Altitude (DA/DH) as
"A specified altitude or height in a 3D instrument approach at which a missed approach must be initiated if the required visual reference has not been establshed" AIP GEN 2.2 page 8.