Why is ADF required on ILS approach?

Gig,

the initial approach fix (IAF) is defined by the NDB. how would you
find this point without an ADF? You'd get around that with radar
vectors, but you couldn't fly the full procedure without the NDB. And
the missed approach is a hold on the NDB. Same problem.

BUT: An approach certified GPS with the NDB in it's database can
replace for the ADF.

--
Thomas Borchert (EDDH)

"Brien K. Meehan" <brien@networkgenius.com> wrote in message
news:vgmdoudq5b5p16@news.supernews.com...
>
> It's an IAF, so there's no previous fix from which you can start timing to
> find LADOS.
>
> DME is not required, so you can't assume you can use it to find LADOS -
yes,
> even though it's clearly marked 5.2NM on the plate.
>
> If you want to get into ELD without an ADF, you'll have to use one of the
> other 3 approaches. Those aren't terrible options.
>

You're ignoring the feeder route from ELD to LADOS.

"Thomas Borchert" <borchert_thomas@m> wrote in message
news:VA.00005f20.00cc06ba@m...
>
> or an approach certified GPS with LADOS as a waypoint, right?
>

The GPS does not need approach certification.

Thomas Borchert wrote:
>>Wait! He can use a GPS in place of the ADF on that approach. Isn't that
>>correct?

> I think so. But: Does the GPS need to be certified? If so (and I think so),
> does it need to be approach certified or is enroute sufficient?

Certified, enroute/terminal suffices

Sydney

That's correct and defines LADOS (the localizer and ELD 018/2miles) I
had a similar problem (before I got my certified GPS) for KGYI. Newly
commissioned ILS and it came out with a ADF REQUIRED on the plate. I
contacted the FAA and we discussed. I also submitted that the outer
marker (DNI) could be easily defined by the feeder route from BYP and
the localizer. I still do not understand the reason; must be something
in the TERPS.

"Steven P. McNicoll" wrote:
>
> "Thomas Borchert" <borchert_thomas@m> wrote in message
> news:VA.00005f1f.00cc0534@m...
> >
> > the initial approach fix (IAF) is defined by the NDB. how would you
> > find this point without an ADF?
> >
>
> There is a feeder route from ELD to LADOS.

Thomas Borchert wrote:

> Rich,
>
> > Wait! He can use a GPS in place of the ADF on that approach. Isn't that
> > correct?
> >
>
> I think so. But: Does the GPS need to be certified? If so (and I think so),
> does it need to be approach certified or is enroute sufficient?

IFR certified, but approach certification is not required.

<joe@obilivan.net> wrote in message news:3F1154BC.3AE33F91@obilivan.net...
>
> You're entitled to your view, of course. But, the "ADF REQUIRED"
> note is a procedural data equipment note issued as part of an
> amendment to 14 CFR 97.
>

Can you cite a source for that?


>
> If in doubt, all the manager of AVN-100 and ask him whether the note is
> advisory in nature. Also, AFS-400 many have a view somewhat
> different than your's.
>

I'm not looking for another opinion, I'm looking for something definitive.