planeandpilotmag.com 35approaches kept those binders a few kilos lighter.
his truth applies to your approach request. You ask for
the ILS or the localizer and get cleared as such, “... cleared
ILS Runway Two hree approach ...” not “... cleared ILS or
localizer Runway Two hree approach.” If you switch from
one to the other part way, say because the glideslope failed,
technically you should get a new clearance. No one cares
in practice, but that’s another discussion as well.
his fact that it’s two approaches is why the correct
name is: “ILS Y or LOC Y Rwy 23” rather than what “ILS
or LOC Y Rwy 23”—and, yes, that means the title of the Y
and Z approaches at KRUT are wrong (as are many others).
his reveals how deep the confusion goes. he charting
oice even had to straighten themselves out. Expect the
incorrect titles to change as charts are updated.
Now that we have this nomenclature straightened
out, check out the Z approach at KRBW. GPS is used for
transition from the enroute environment with no-PT
sectors allowing direct LAMKE. hat’s a great beneit for
GPS-equipped aircraft, but it’s not required because you
could arrive at LAMKE via airway, just like the Y approach.
he DME requirement in the notes section is for the same
reason as the Y chart: it’s only for the localizer version. Per
FAA policy, you may substitute GPS.
However, the Z approach has a different missed
approach procedure in that you go GPS-direct to STOAS
rather than intercepting a radial east of STOAS and then
proceeding outbound. his requires GPS—and applies to
both the ILS and the localizer approaches.
herefore, what “GPS and DME required” should actually
say is “GPS required for ILS Z or LOC Z missed approach
procedure. DME required for LOC approach, and you can
substitute GPS for that if you want.”
And that’s essentially what the FAA will be doing in the
future. A new area in the brieing strips will specify what’s
required for what. I don’t have the details, but I’ll be happy
to see it put into efect.
Now I hear the cry: “If GPS is required no matter what,
and GPS can substitute for DME, why bother saying DME
is required at all?” In this case, there’s no good reason
other than consistency. However, if the Y and Z had dif-
ferent minimums you could, in theory, ask for a missed
approach procedure that didn’t require DME and thereby
obviate the need.If GPS can substitute for DME, then why do some charts specifically say that both DME and GPS are required? Good question, and there is an answer. As in
most cases with apparent chart ambiguities, it's just not an obvious answer.