stepdown fixes on RNAV approach with L/VNAV or LPV

pierre

Well-Known Member
http://aeronav.faa.gov/d-tpp/1206/06646R25L.PDF

The DVT RNAV GPS 25L approach includes the stepdown fix "GIGEC" inside the FAF. THe altitude at GIGEC is published as a mandatory crossing altitude of 2940. My question is why does the 2940 @ GIGEC not have an asterisk indicating that the 2940 is for LNAV only? Plenty of LPV procedures have a stepdown fix inside the FAF but I can think of none that do not indicate LNAV only at that fix. Jeppessen charts agree with the NOS.

Follow up question: How do you comply with this while flying the LPV GS? Doesn't that somewhat defeat the purpose of following a GS to a DA?
 
At first glance, I'm convinced that the "* LNAV ONLY" designation should apply to GIGEC, and that it was improperly omitted by the publishers of the chart. Every other RNAV (GPS, LPV and LNAV/VNAV or LNAV) procedure I've looked at has all such intermediate step-downs on the final segment designated LNAV ONLY. I'm not sure who to ask at the FAA about this, but it seems to be to be an omission in the plate. I'd look for a terminal procedures NOTAM on the subject, to tell you the truth. Might say "S-RNAV ... - GIGEC - LNAV ONLY" or something to that effect.

Minor nitpick: For what it's worth, mandatory altitudes on NOS charts are indicated with both under- and overscores (and in small caps MANDATORY on Jeppesen charts). GIGEC is more accurately described as a minimum altitude of 2,940 MSL as it is merely underscored.

That said, that's at first glance, and other than "works good, lasts long time" I can't confess to knowing much about LPV approaches despite having shot lots of them.
 
I'm also of the opinion that it's an error. In terms of who to call, I have no clue, but the local FSDO would be a good start.
 
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