Why do some approaches only have VNAV minima?

[applecrumble]

Some approaches only show an LNAV minima and not a VNAV/LNAV minima as well?
Thank you in advance

[galaxy flyer]

Use the search function, this subject was done and dusted about a year ago.

Post the approach because there cannot be an approach w/o lateral navigation.

[underfire]

Post the approach because there cannot be an approach w/o lateral navigation.

never say never in this business....

Apple, yes, please provide the approach plate. One can get creative and use a VNAV SPD and VNAV PTH from TOD, but I would have to really understand why there would be minima.

[applecrumble]

I see what guys are saying and you are all of course correct you require a lateral course to have any form of Rnav app.
What I am actually referring to is where you only have an LNAV minima displayed on the plate. Usually you have an LNAV/VNAV minima as well which has lower minimums (typically).

http://vau.aero/navdb/chart/LTBS.pdf

Have a look at Dalaman GNSS 19. Only an LNAV minima is given.
My thoughts are that because of the terrain the approach designer couldn't come up with an LNAV/VNAV minima that was lower than the LNAV only minima so they just didn't publish one?

[wiedehopf]

the title of the thread should be ... "why do some approaches only have LNAV minima?"

because that is how the situation is with the mentioned approach.

[applecrumble]

You are absolutely correct! I was very tired when I posted this. Sorry!

[westhawk]

A fair number of RNAV/GPS approaches here in the US have LNAV mins that are lower than the LNAV/VNAV mins. I've speculated as to why that is, but haven't seen a reference that either confirms or refutes my theory as to why that is. Anyone else believe it has to do with the obstacle clearance plane between the "on glidepath" at DA and the runway versus that of the "at the MAP at MDA?"

[applecrumble]

That is correct under TERPS procedure design.
Anyone know for PANS-OPS?
My guess is it's much the same.

[EMIT]

When LNAV minimum is lower than LNAV/VNAV minimum, that could be because of temperature considerations:
The LNAV/VNAV minimum is valid down to the published minimum temperature stated on the chart.
The stated minimum temperature is not valid for the LNAV minimum - that minimum has to be corrected in case of temperatures below ISA and the result of a comparison near the charted minimum temperature could well be that the LNAV only minimum is then higher than the LNAV/VNAV minimum.

[underfire]

apple, revise the title the thread then....

edit
go advanced
fix title

[Nick 1]

What is the difference between LPV, LNAV/VNAV and LNAV approach minima? | ThinkAviation (http://thinkaviation.net/difference-between-lpv-lnav-vnav-and-lnav-minima/)