ADF and GPS equip %

In article . com,
says...


In a small GA plane, THE panel to have has, an IFR GPS, a VOR/GS, a
radio, a transponder and an all electric autopilot. You fly the GPS for
enroute and then take the ILS or VOR approach.

I know I'm getting heavy here, but the ILS may still have an ADF
requirement if there's a LOM in the missed approach segment. If your IFR
GPS is of the TSO C129 type, I don't think you can file this without a
working ADF in the plane. And if you get a RAIM warning, with no ADF in
the plane, you just have to go somewhere else.

GF

Doug wrote:
In a small GA plane, THE panel to have has, an IFR GPS, a VOR/GS, a
radio, a transponder and an all electric autopilot. You fly the GPS for
enroute and then take the ILS or VOR approach. If your vacuum fails you
still have your autopilot, and if your electric fails you still have
your vacuum. Back this up with a handheld radio and a handheld GPS and
you are set to go.

No need for ADF, DME, or marker beacons. They are all avionics of the
past. No need for an HSI becuase you have the autopilot coupled to the
GPS.

Another good reason to get rid of all the extra stuff is repair. The
less you have, the less you need to repair.

Exactly right, with one qualification: make the GPS TSO C146 (e.g. GNS480). No
worries about filing alternates with GPS approaches, seamless transition from
enroute GPS environment to approach GPS environment, glide slope available to
most airports, ILS-equipped or not. Use ILS approaches only if you need the
absolute lowest minima. This is US-centric, of course.

Dave

New usage for ADF's. Listen to ball games and deduce TFR's.

An IFR GPS is a legal substituter for "ADF Required" notation on an ILS
approach. See AIM.

I personally have not seen any GPS approaches that use the glideslope
feature of the 480, but I may have been missing something. I agree,
that a glideslpe for a non-precision approach is a great idea and if
the 480 can do it, then that is the one to have (for a price no doubt).

Doug wrote:
I personally have not seen any GPS approaches that use the glideslope
feature of the 480, but I may have been missing something. I agree,
that a glideslpe for a non-precision approach is a great idea and if
the 480 can do it, then that is the one to have (for a price no doubt).

I fly them all the time. I must admit that I don't understand all the
nuances of exactly which approaches have it (i.e. even some that don't
have VNAV minima published on the plate), but the bottom line is a
message pops up on the GNS-480 display saying, "LNAV/VNAV", and the
glide slope needle comes alive. From there on, just keep the needles
in the donut, just like on an ILS.

Installed price is about $10k.

"Roy Smith" wrote in message ...
Doug wrote:
I personally have not seen any GPS approaches that use the glideslope
feature of the 480, but I may have been missing something. I agree,
that a glideslpe for a non-precision approach is a great idea and if
the 480 can do it, then that is the one to have (for a price no doubt).

I fly them all the time. I must admit that I don't understand all the
nuances of exactly which approaches have it (i.e. even some that don't
have VNAV minima published on the plate), but the bottom line is a
message pops up on the GNS-480 display saying, "LNAV/VNAV", and the
glide slope needle comes alive. From there on, just keep the needles
in the donut, just like on an ILS.

Installed price is about $10k.


I don't understand those nuances of which approaches are VNAV, either.
But last week I flew one which my CNX80 told me was
"Downgraded to LNAV only" (or some wording similar to that),
and I instantly thought "How crude! Now I'll have to 'dive and drive'."
Until then, I didn't realize how accustomed I'd grown to LNAV/VNAV.
For Doug's benefit, it seems that the overwhelming majority of GPS
approaches allow VNAV guidance.

Roy neglected to say that in addition to *flying* "just like on an ILS",
autopilots can make fully coupled LNAV/VNAV approaches, too.
TSO-C146 rocks!

I am puzzled also. Even some newly commisioned ILS approaches require
ADFs to locate the outermarker for hold. We had one at a local airport
and I wrote to OK City and they agreed that they rushed the design. I
commented that the hold point could easily be located by the localizer,
the feeder route from the nearby VOR, and the marker beacon. However,
when the genius redesigned the procedure they had us flying 40 miles out
of the way to hold, not evening using the feeder VOR, but another one. I
withdrew my letter. They left the procedure with the ADF required. I
have noticed a couple of other approaches in the area that had changes
adding the ADF requirement. According to the designers, this provides a
lesser workload on the pilot flying the missed approach.

Greg Farris wrote:

I came across the same question recently, as I happened in one day to see
three Cessna panels with full-on Garmin panels but no ADF. So I did an
informal look at Trade-A-Plane, which confirms the tendancy. I get the
impression that a good 50% of those overhauling their panel chose to
chuck the ADF, and the proportion of new panels delivered (pre-G1000)
without ADF is similar, if not higher.

This puzzles me, because of the number of approaches still published with
ADF requirement - why spend thousands to have the latest and greatest,
if it's to restrict your use of so many approaches? I'm aware that many
instrument students prefer not to have it, because if it's there they
will be asked to demonstrate proficiency with it on the checkride - yet
I fail to understand just why this requirement strikes terror in peoples'
hearts!

I am also saddened to see the DME go, which seems to be part of the same
trend, though I do accept the argument that with a G430 and a G530
stacked in the panel you're hardly getting any more information from a
DME!

As for RMI - sure it's great to have a VOR/NDB RMI for your DME arcs etc,
but how many piston singles actually have this? I see them in KingAirs,
but not in 172's.

GF

In article om,
says...


An IFR GPS is a legal substituter for "ADF Required" notation on an ILS
approach. See AIM.

There are restrictions. See AIM.
See other posts in current thread.
There are also different types of "IFR GPS" - that notation is no longer
sufficient.

GF

In article ,
says...

It restricts you in the alternate airport choice.

One can argue this two ways: legally and from the POV of systems
reliability. (And I know *you* are not in the USA )

(text cut for brevity)

A lot of European VFR flying (and probably a fair bit of US VFR
flying?) is done without radar assistance; often without any
assistance whatever.

There are quite a few services available in the US - new and old - that have
never existed in Europe (HIWAS, TWEB, WAAS, LAAS, many types of briefings)
however general flight information service (VFR Flight Following) is available
in most places, and VFR pilots may elect to use it or not, as in the US.


I am a great fan of GPS and use my IFR KLN94/KMD550 for navigation
100% of the time, but I also like my VOR, DME and ADF. The ADF is
mandatory in much of Europe anyway, and there are large stretches of
France, Spain, etc, where you can't pick up a VOR but can pick up some
NDB, so you still have a nav backup to the GPS. In the 3rd world, an
ADF is a must. Also, for those who like to route via navaids for the
above backup reasons, the ability to route via an NDB gives you
additional VFR route planning options.


I do not see many places in Europe where you don't have several VOR's
available, and I don't know of any places where one must use NDB's for en-route
navigation. On the other hand, there are quite a few NDB approaches, at many
smaller airports the only instrument approach will be an NDB - and even
though there is usually a perfunctory GPS overlay, the Europeans have basically
elected to trash free GPS in order to benefit from the priviledge of waiting
another ten years and paying high user fees for Galileo, so the whole
constellation of GPS-based services for IFR approaches is simply a non-starter
in Europe.

GF