Garmin 430 rquestion- does the approach always have to be activated via "activate approach"?

I believe the only time you can ignore a course reversal is:
* Timed approach from a fix
* Coming in on a segment labeled NoPT (such as the typical left or right IAF
on a standard "T" GPS approach)
* Vectors to Final.

Cleared direct to the IF/IAF doesn't necessarily mean you're getting
vectors. Maybe, maybe not. I've been cleared to an IF/IAF just to get me in
line farther out from the FAF. Shortly before getting to the IF/IAF, I'm
given the spiel of "x miles from FAF, maintain y until..." Thump the Vectors
to Final button OR just take the GPS out of OBS HOLD mode & on to the FAF
you go.

If I don't hear the controller tell me I'm getting vectors to final, I will
ask. If it turns out I'm not, I've got the full approach already up &
running.


"Sam Spade" wrote in message
...
John Collins wrote:

An Intermediate Fix may also be an Initial Approach Fix.

A typical example is a T style approach, where both the right base and
the
left base ends are IAFs and the top center of the T is an IF, but not an
IAF. See http://204.108.4.16/d-tpp/0802/05726R5.PDF

There are numerous examples of the top center being both an IF and an
IAF.
See http://204.108.4.16/d-tpp/0802/05683R28.PDF

When an IF is also an IAF, you can select the IF(IAF) in the select
approach
dialog.

Actually, it is only (and always) when it has a hold-in-lieu course
reversal.

Next question: If a controller clears you directly to an IF/IAF do you
always disregard the hold-in-lieu course reversal and go straight-in?

Steven Barnes wrote:
I believe the only time you can ignore a course reversal is:
* Timed approach from a fix
* Coming in on a segment labeled NoPT (such as the typical left or right IAF
on a standard "T" GPS approach)
* Vectors to Final.

Cleared direct to the IF/IAF doesn't necessarily mean you're getting
vectors. Maybe, maybe not. I've been cleared to an IF/IAF just to get me in
line farther out from the FAF. Shortly before getting to the IF/IAF, I'm
given the spiel of "x miles from FAF, maintain y until..." Thump the Vectors
to Final button OR just take the GPS out of OBS HOLD mode & on to the FAF
you go.

If I don't hear the controller tell me I'm getting vectors to final, I will
ask. If it turns out I'm not, I've got the full approach already up &
running.

You need to get up to date on this procedure. It became policy about
three AIMs back.

"Sam Spade" wrote in message
...
Stan Prevost wrote:

"Sam Spade" wrote in message
...

John Collins wrote:


When an approach is loaded, it is appended to the flight plan after the
destination airport. As stated earlier, the waypoints in the original
flight plan will sequence normally until the destination airport is
reached, at which time the 430 will navigate direct to the IAF waypoint
and automatically "activate" the approach sequence.


To cut to the chase, those of us familiar with using FMSes know to clear
the destination airport from the flight plan once the approach is
loaded. In a full-press FMS, this is known as a route-discontinuity.
And, clearing that discontinuity in a full-press FMS or a Garmin panel
mount will get it all to work as a flight plan with continuity.


On a GNS430, activating the loaded approach is simpler. PROC, ENTER.


I took another look at it and disagree. Once the IAP is selected removing
the airport can be done prior to a critical phase of flight, then
everything sequences without pilot intervention.


FPL, push small knob to get cursor, scroll down to airport, CLR, ENTER to
confirm, FPL to get back to NAV page.

vs

PROC, ENTER.

And if you have to change approaches, which sometimes happens, you can't
select a new one without a destination airport.

Stan Prevost wrote:

FPL, push small knob to get cursor, scroll down to airport, CLR, ENTER
to confirm, FPL to get back to NAV page.

vs

PROC, ENTER.

True enough. But, the bit of extra stuff earlier on is none the less
easier and I don't have to worry about making sure I am where I am
supposed to be if I "activate."

And if you have to change approaches, which sometimes happens, you can't
select a new one without a destination airport.

It is rare to fly the full approach in a TRACON environment. But, if it
is a single approach in each direction, you will usually still know
early on. If it is a major airport then all bets are off, so I would
wait until the vectors begin, then do it your way, but with VTF.

However, if the airport has runway specific STARs, then there is another
level of complexity, which can easily overwhelm single-pilot operations.

"Sam Spade" wrote in message
...
Stan Prevost wrote:

FPL, push small knob to get cursor, scroll down to airport, CLR, ENTER to
confirm, FPL to get back to NAV page.

vs

PROC, ENTER.

True enough. But, the bit of extra stuff earlier on is none the less
easier and I don't have to worry about making sure I am where I am
supposed to be if I "activate."

And if you have to change approaches, which sometimes happens, you can't
select a new one without a destination airport.


John Collins informed me, and I confirmed on the sim, that if you delete the
destination airport waypoint from the flight plan, and then need to select a
different approach, the 430 will assume the former destination airport and
will allow you to select a new procedure at that airport.

It is rare to fly the full approach in a TRACON environment. But, if it
is a single approach in each direction, you will usually still know early
on.

I don't find that it is rare to fly an RNAV approach from an IAF at a
satellite airport served by a TRACON (yes at the primary airport). VOR
approaches or others with PTs, yes, but not Basic T and TAA GPS approaches.
But it is not too uncommon for an airport or runway to be turned around
after you have been told what approach to expect.

On Sun, 17 Feb 2008 05:51:36 -0800, Sam Spade
wrote:

On a GNS430, activating the loaded approach is simpler. PROC, ENTER.


I took another look at it and disagree. Once the IAP is selected
removing the airport can be done prior to a critical phase of flight,
then everything sequences without pilot intervention.

Exactly, seems simpler to me.

"Sam Spade" wrote in message
...
Stan Prevost wrote:

FPL, push small knob to get cursor, scroll down to airport, CLR, ENTER to
confirm, FPL to get back to NAV page.

vs

PROC, ENTER.

True enough. But, the bit of extra stuff earlier on is none the less
easier and I don't have to worry about making sure I am where I am
supposed to be if I "activate."



(and from another post)
I took another look at it and disagree. Once the IAP is selected removing
the airport can be done prior to a critical phase of flight, then
everything sequences without pilot intervention

Sam, I have reread your posts trying to make sure I understand your points.
First of all, I didn't know the Garmins would self-activate, so that is
something new I have learned from this thread. More on that later. I
understand that you prefer to perform a more complex task rather than a
two-button-task if you can move the task to a less busy period of the
flight. But the "without pilot intervention" part only happens if you were
already direct to the IAF at the time you deleted the airport waypoint, or
deleted the airport waypoint to make the navigator sequence to the IAF when
instructed to proceed direct to the IAF. Either way, it is the same result
as the simpler activation procedure performed at the same point in time. If
that is not true, then I am missing something in the scenario. Perhaps a
simple example would help.

As far as I can determine, the self-activation feature is not mentioned in
the Garmin manuals. I believe another poster said the same. Personally, I
am a bit uneasy about using undocumented "features" of software in critical
situations. For one thing, we don't really know what is happening and if it
has even been tested. Does it do the required RAIM predictions prior to the
FAF? How would you know, unless it fails? Does this "feature" work under
all conditions? Another thing, you don't know if the "feature" will still
exist, or work the same way, if the software is updated.

I wonder what the response would be if one called Garmin and asked if they
approve using the navigator this way? Or the FAA?

Stan

On 2/17/2008 4:54 PM, Stan Prevost wrote the following:
snip

I wonder what the response would be if one called Garmin and asked if
they approve using the navigator this way?

Try it! I have had extremely good luck with Garmin tech support transferring me
to very knowledgeable people when I had something besides the usual RTFM
questions. My guess is that the manuals are the problem and that the behavior
is in the design spec.

Well, let me posit a scenario.

Flight Plan:

KABC WPTA WPTB WPTC KDEF

After passing WPTB, I either conclude on my own that APPRCH 1 to KDEF is
what I expect, or I am told to expect it. So I select APPRCH1, from IAF1,
and load it. Now the flight plan is

KABC WPTA WPTB WPTC KDEF IAF1 IF FAF MAP MAHP.

I delete the destination airport which causes a discontinuity (lots of
buttons and knobs):

KABC WPTA WPTB WPTC IAF1 IF FAF MAP MAHP.

Now I am still flying with WPTC as the TO waypoint, with the next waypoint
being IAF1.

Now, Case 1: I continue flying to WPTC, on passing it the machine sequences
to IAF1. But I have not been cleared to IAF1, I am still cleared to KDEF.
Problem. Requires unexpected actions. I have to fix it by entering direct
to a waypoint not in the flight plan. Lots of button/knob actions. I'm too
lazy to type it all in.

Case 2: Before reaching WPTC, I am cleared direct to IAF1. Requires pilot
intervention: FPL, press small button to get cursor, scroll down using
large knob to IAF1, Direct, Enter, Enter, FPL. Or, FPL, press small button
to get cursor, scroll down using large knob to WPTC, CLR, ENTER, FPL.

Case 3: I continue flying original flight plan, navigator continues to
sequence along cleared flight plan until I am cleared to fly direct IAF1.
PROC, ENTER, done.

Case 4: I figure that I will get Vectors To Final. So I load the approach,
with an IAF selected or with VTF selected. I delete the destination airport
waypoint. After passing the last enroute waypoint, the machine will
sequence to the IAF, if any, or to the FAF, if VTF. Is its action
consistent with my clearance at that point? As opposed to: upon receiving
the first vector, press PROC, ENTER (if VTF was loaded, otherwise scroll to
the VTF option on the menu and ENTER).

Do these scenarios miss the point?

Stan







"Stan Prevost" wrote in message
...

"Sam Spade" wrote in message
...
Stan Prevost wrote:

FPL, push small knob to get cursor, scroll down to airport, CLR, ENTER
to confirm, FPL to get back to NAV page.

vs

PROC, ENTER.

True enough. But, the bit of extra stuff earlier on is none the less
easier and I don't have to worry about making sure I am where I am
supposed to be if I "activate."



(and from another post)
I took another look at it and disagree. Once the IAP is selected removing
the airport can be done prior to a critical phase of flight, then
everything sequences without pilot intervention

Sam, I have reread your posts trying to make sure I understand your
points. First of all, I didn't know the Garmins would self-activate, so
that is something new I have learned from this thread. More on that
later. I understand that you prefer to perform a more complex task rather
than a two-button-task if you can move the task to a less busy period of
the flight. But the "without pilot intervention" part only happens if you
were already direct to the IAF at the time you deleted the airport
waypoint, or deleted the airport waypoint to make the navigator sequence
to the IAF when instructed to proceed direct to the IAF. Either way, it
is the same result as the simpler activation procedure performed at the
same point in time. If that is not true, then I am missing something in
the scenario. Perhaps a simple example would help.

As far as I can determine, the self-activation feature is not mentioned in
the Garmin manuals. I believe another poster said the same. Personally,
I am a bit uneasy about using undocumented "features" of software in
critical situations. For one thing, we don't really know what is
happening and if it has even been tested. Does it do the required RAIM
predictions prior to the FAF? How would you know, unless it fails? Does
this "feature" work under all conditions? Another thing, you don't know
if the "feature" will still exist, or work the same way, if the software
is updated.

I wonder what the response would be if one called Garmin and asked if they
approve using the navigator this way? Or the FAA?

Stan

"Mitty" wrote in message
...


On 2/17/2008 4:54 PM, Stan Prevost wrote the following:
snip

I wonder what the response would be if one called Garmin and asked if
they approve using the navigator this way?

Try it! I have had extremely good luck with Garmin tech support
transferring me to very knowledgeable people when I had something besides
the usual RTFM questions. My guess is that the manuals are the problem
and that the behavior is in the design spec.

I would call them if I understood why I might have anything to gain from
doing so. I don't yet understand how using the undocumented self-activation
"feature" helps anything.

Stan