What is purpose of mixing LOC/VNAV in this landing method?
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4$\begingroup$ The purpose is landing, could you be a bit more specific with your question? $\endgroup$ – GdD Aug 3 '17 at 7:48
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$\begingroup$ There are many landing modes (FLS, ILS, MLS etc..) but when will we use Mix LOC/VNAV landing method ? $\endgroup$ – Hosakoti Santhosha Aug 3 '17 at 9:04
A VNAV with localiser approach is normally a backup to a regular ILS should there be a glide slope unserviceability. The use of VNAV to manage the vertical portion of the approach would allow the use of APV minima which are normally lower than using a vertical speed mode.
VNAV is a better mode when conducting non-precision approaches as the aircraft is still following a defined glideslope - albeit derived from a database - which is more accurate than trying to follow a tabled set of heights and distances using vertical speed.