GPS vs ADF

I'm still a little confused how I'm expected to legally fly an ILS approach that
uses a NDB as its IAF with a GPS on board instead of an ADF. (For example, the
ILS Runway 2 approach into KUZA (Rock Hill, SC)). The rental aircraft I have
access to these days all come with GPS, which is very nice, but I still want my
ADF for the little airports I sometimes fly into.

Feel free to educate me... I was out of flying for 15 years and the technology
passed me by. The last time I was flying regularly LORAN was just coming to
aircraft, and everybody was flying ILS, NDB, and VOR approaches. I took an IPC
to get my instrument currency up to date but we used the older equipment with
which I was already familiar. I'm comfortable enough setting up a Garmin 430 to
navigate to another airport but that's about the limits of what I can do with
one. Don't have a clue about GPS approaches....

Some people refer to IFR GPS as "flexible," meaning it can do many
different things. Some refer to is as "a frustrating piece of crap,"
because they find it so hard to make it do any one particular thing. I
find that the user interfaces on GPS units are very intuitive and
obvious - as long as you have a graduate degree in engineering and
several years experience working with computerized instrumentation.
Describing IFR GPS as flexible is a lot like saying a drowning victim
has moist skin. It's technically true, but you're not impressed.

There are lots of ways to accomplish what you want - that is, to use an
IFR GPS instead of an ADF to fly an ILS approach where the IAF and MAP
is a LOM. If you're used to doing it the old fashioned way, then the
method that will make sense to you will be the one that all the people
who actually like and understand IFR GPS will consider the least
desirable (and it's one I probably would not use myself unless I was
unfamiliar with the available GPS). Here goes:

Use exactly the keystrokes you would use to make the IFR GPS point to
the airport (meaning the direct-to function). However, instead of
dialing in KUZA for the airport, dial in RALLY (the intersection that
marks the LOM).

To fly the approach:

Go direct to RALLY as you would to an airport. When the distance from
RALLY reads close to zero (say less than 0.5 nm) turn outbound and
track the LOC outbound, and when ready perform the PT. Proceed as with
a normal ILS. The GPS will probably give you numeric absolute bearing
to RALLY just as an ADF would, only better, and also distance to RALLY.

To fly the missed approach:

Upon starting your climbing turn to the left, do the same direct-to you
did before (you should not need to dial in RALLY again, so probably
just direct-to and enter or the equivalent - two keystrokes - will be
required) and fly direct to RALLY. Make the teardrop entry as normal,
and use the LOC for guidance on the inbound leg.

There are other ways to do this. Many other ways. IFR GPS is very
flexible and powerful. With a 430, you can get a diagram of the
approach to come up, get guidance to the IAF, lines to follow for your
PT, and automatic switching to LOC mode when established inbound as
well as automatic sequencing for the missed approach with a visual
depiction of the hold and prompting for the correct entry. But the
basic method I gave you will always work with any GPS, and will seem
natural to someone who is used to flying steam gauges.

Michael

Michael wrote:

Some people refer to IFR GPS as "flexible," meaning it can do many
different things.

I like my GPS, and I am an engineer...but what's really the key to
me is the moving map. You can take away my autopilot, but the
you'll get the map when you pry it out of my cold dead fingers :-)

Michael wrote:
Upon starting your climbing turn to the left, do the same direct-to you
did before (you should not need to dial in RALLY again, so probably
just direct-to and enter or the equivalent - two keystrokes - will be
required) and fly direct to RALLY. Make the teardrop entry as normal,
and use the LOC for guidance on the inbound leg.

There are other ways to do this. Many other ways. IFR GPS is very
flexible and powerful. With a 430, you can get a diagram of the
approach to come up, get guidance to the IAF, lines to follow for your
PT, and automatic switching to LOC mode when established inbound as
well as automatic sequencing for the missed approach with a visual
depiction of the hold and prompting for the correct entry. But the
basic method I gave you will always work with any GPS, and will seem
natural to someone who is used to flying steam gauges.


That was exactly the information I was looking for. Thank you for taking the
time to post it.



--
Mortimer Schnerd, RN
mschnerdatcarolina.rr.com

Michael wrote:

Some people refer to IFR GPS as "flexible," meaning it can do many
different things. Some refer to is as "a frustrating piece of crap,"
because they find it so hard to make it do any one particular thing. I
find that the user interfaces on GPS units are very intuitive and
obvious - as long as you have a graduate degree in engineering and
several years experience working with computerized instrumentation.
Describing IFR GPS as flexible is a lot like saying a drowning victim
has moist skin. It's technically true, but you're not impressed.

x

Some folks with a lot of professional flying experience find some of
this stuff quite flexible and useful. Sure don't have to be an
engineer. But, it is sure equipment specific. I am proficient in the
use of the Garmin 530 but that took some time.

I wouldn't even attempt to use any other panel mount without a similar
amount of learning and practice. I also find using the 530 in a single
pilot environment without an autopilot to be a excessive knob twisting,
bad human-factors situation.

Sam Spade wrote:
Some folks with a lot of professional flying experience find some of
this stuff quite flexible and useful.

And I do as well.

Sure don't have to be an engineer.

I'm not sure that's true. I find that those without an engineering
background find it counterintuitive and need a lot of time to get used
to it. At least that has been my experience teaching people to use
their 430's, 530's, etc.

But, it is sure equipment specific. I am proficient in the
use of the Garmin 530 but that took some time.

How much time did it take to become proficient in the use of other
navigation equipment, once the basic instrument rating was attained?

I wouldn't even attempt to use any other panel mount without a similar
amount of learning and practice.

Which took how long? I've heard estimates in the 10-40 hour range.

I also find using the 530 in a single
pilot environment without an autopilot to be a excessive knob twisting,
bad human-factors situation.

So let's see. You find that you need a significant amount of learning
and practice to use one particular make of GPS, that much of this won't
carry over to another make, and that even after you have learned to use
it, the workload required to use it single pilot without autopilot to
be excessive. I'm not surprised.

I find it to be quite flexible and useful, and without those caveats -
I find the workload of a 530 to be quite low, and the learning curve to
be quite short. Of course I have a graduate degree in engineering and
significant experience designing and using computerized equipment.

It didn't have to be that way. If it were up to me, GPS approaches
would be designed the same way as on-field VOR-DME approaches without a
FAF. You have the MAP/holding fix and a radial. You select the MAP,
put the unit in OBS mode, select the radial, and fly the standard
approach with PT in a manner familiar to every instrument rating holder
out there. If you need stepdown fixes, you add them. The interface to
the essential unit functionality could thus be standard and familiar.
But it wasn't done that way.

Michael

Michael wrote:

I'm not sure that's true. I find that those without an engineering
background find it counterintuitive and need a lot of time to get used
to it. At least that has been my experience teaching people to use
their 430's, 530's, etc.


What was the average age of the person you were teaching?

B A R R Y wrote:
I'm not sure that's true. I find that those without an engineering
background find it counterintuitive and need a lot of time to get used
to it. At least that has been my experience teaching people to use
their 430's, 530's, etc.

What was the average age of the person you were teaching?

About average for the pilot-owner. That is to say, maybe 45.

Younger people always learn faster.

The interesting thing is that the ones who did have significant
relevant experience (I'm thinking a couple of engineers here) got it
instantly. The others needed a lot of work.

Michael

Michael wrote:
Sam Spade wrote:

Some folks with a lot of professional flying experience find some of
this stuff quite flexible and useful.


And I do as well.


Sure don't have to be an engineer.


I'm not sure that's true. I find that those without an engineering
background find it counterintuitive and need a lot of time to get used
to it. At least that has been my experience teaching people to use
their 430's, 530's, etc.


But, it is sure equipment specific. I am proficient in the
use of the Garmin 530 but that took some time.


How much time did it take to become proficient in the use of other
navigation equipment, once the basic instrument rating was attained?

Well, I got my instrument rating in 1958. ;-)


I wouldn't even attempt to use any other panel mount without a similar
amount of learning and practice.


Which took how long? I've heard estimates in the 10-40 hour range.

Around 10 hours using the Garmin trainer integrated with MSFS.


I also find using the 530 in a single
pilot environment without an autopilot to be a excessive knob twisting,
bad human-factors situation.


So let's see. You find that you need a significant amount of learning
and practice to use one particular make of GPS, that much of this won't
carry over to another make, and that even after you have learned to use
it, the workload required to use it single pilot without autopilot to
be excessive. I'm not surprised.

Yes, I am a retired airline pilot who, after a lot of early G/A
experience, got used to a far better human-factors environment in
airline flight operations.

I find it to be quite flexible and useful, and without those caveats -
I find the workload of a 530 to be quite low, and the learning curve to
be quite short. Of course I have a graduate degree in engineering and
significant experience designing and using computerized equipment.

A lot of it has to do with a trained mind that could be in disciplines
other than engineering.

It didn't have to be that way. If it were up to me, GPS approaches
would be designed the same way as on-field VOR-DME approaches without a
FAF. You have the MAP/holding fix and a radial. You select the MAP,
put the unit in OBS mode, select the radial, and fly the standard
approach with PT in a manner familiar to every instrument rating holder
out there. If you need stepdown fixes, you add them. The interface to
the essential unit functionality could thus be standard and familiar.
But it wasn't done that way.

You are thinking too much in light aircraft terms. All this stuff is
designed for the airlines, who own the FAA.

Michael,

I find that those without an engineering
background find it counterintuitive and need a lot of time to get used
to it.


If I may: So what? Who says things in life have to be easy or
"intuitive"? A GPS does very complex things. So it is complex to use. Is
any of those people you teach really of the opinion that a CDI or an ADF
are more "intutitive" than a moving map? Yeah, right...

--
Thomas Borchert (EDDH)

Michael wrote:
B A R R Y wrote:
I'm not sure that's true. I find that those without an engineering
background find it counterintuitive and need a lot of time to get used
to it. At least that has been my experience teaching people to use
their 430's, 530's, etc.
What was the average age of the person you were teaching?

About average for the pilot-owner. That is to say, maybe 45.

Younger people always learn faster.

I wasn't so much leaning that way, but more toward the video game
generation and folks who don't know the "old" way.

I teach technicians how to use high-tech test gear, and the folks who
have all kinds of experience with analog gear covered with discrete
switches always take longer to learn than the "new" folks, even though
the more experienced folks understand what they're testing and why.

I find that the older folks often try to relate the new device back to
the old tools, while the younger ones don't have anything to relate to,
so they accept things at face value. After modifying the teaching
method to NOT relate as much to the older methods, I find the more
experienced folks learning much faster.