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

On 02/16/08 10:46, Thomas Borchert wrote:
> Terence,
>
>> Well suppose I am enroute and approaching the SGD VOR. At this point I
>> am getting close to my destination and want to setup the KCCR VOR
>> approach which starts at the CCR IAF. If I load and activate the
>> approach a megenta line will immediately be drawn from my present
>> position to CCR. Want I want is the route SGD, CCR ... KCCR.
>>
>
> I see. In that case, what's wrong with loading the procedure and then
> waiting with activation until passing SGD.
>
> Also, upon rereading the 430 manual I noticed that activating
> vectors-to-final will always get you to the FAF. I could find no mention
> of the automatic activation mentioned by someone. However, automatic CDI
> switching (to VLOC) will only happen on an activated procedure, it
> seems.

... and the localizer frequency must be in the active window -FYI.


--
Mark Hansen, PP-ASEL, Instrument Airplane, USUA Ultralight Pilot
Cal Aggie Flying Farmers
Sacramento, CA

Sam,

> VLOC is only for ILS and LOC, not RNAV
>

I know. However, procedure activation is treated as standard in the
manual, contrary to what you alluded to. There is no mention of
"automatic activation" I could find. Could you kindly point me to it?


--
Thomas Borchert (EDDH)

On Sat, 16 Feb 2008 19:46:19 +0100, Thomas Borchert
<borchert_thomas@************> wrote:

>Terence,
>
>> Well suppose I am enroute and approaching the SGD VOR. At this point I
>> am getting close to my destination and want to setup the KCCR VOR
>> approach which starts at the CCR IAF. If I load and activate the
>> approach a megenta line will immediately be drawn from my present
>> position to CCR. Want I want is the route SGD, CCR ... KCCR.
>>
>
>I see. In that case, what's wrong with loading the procedure and then
>waiting with activation until passing SGD.

Not really biggie, but it seems redundant. Why am I activating? What
does it do? I just passed SGD and I'm en route to CCR with a nice
magenta line plotted between the two. Activating the approach will
redraw a magenta line from my current position to CCR.

As I said, I'm confused about what "activate" actually does. Is it
just a shortcut to get me on the approach or does it put the 430 into
some sort of magical approach mode? Or to put it another way, if I
load but don't activate, am I missing something?


>
>Also, upon rereading the 430 manual I noticed that activating
>vectors-to-final will always get you to the FAF.

One of the annoyances of VTF is that it erases all the waypoints
before the FAF. I'm not that experienced, but when ATC has given me
vectors, it's usually to a fix before the FAF. The bottom line is I
don't use VTF, it's safer to pick an IAF, and then activate the
appropriate leg manually once ATC has issued vectors onto the
published approach.


> I could find no mention
>of the automatic activation mentioned by someone. However, automatic CDI
>switching (to VLOC) will only happen on an activated procedure, it
>seems.

I'll have to read about that. I wasn't aware that the unit
automatically switches from VLOC to GPS or vice versa.

Mark,

> ... and the localizer frequency must be in the active window -FYI.
>

Yep, but the unit will remind you to put it there 3 (?) miles from the
FAF.

--
Thomas Borchert (EDDH)

Terence,

> I wasn't aware that the unit
> automatically switches from VLOC to GPS or vice versa.
>

Me neither ;-)

It switches from GPS to VLOC only, on the condition that the VLOC
frequency is active, once you are kind of established on the final
approach course. Also, it switches "gradually", so as to not make the
autopilot go berserk.

--
Thomas Borchert (EDDH)

Thomas Borchert wrote:
> Sam,
>
>
>>VLOC is only for ILS and LOC, not RNAV
>>
>
>
> I know. However, procedure activation is treated as standard in the
> manual, contrary to what you alluded to. There is no mention of
> "automatic activation" I could find. Could you kindly point me to it?
>
>
No, there is no approach activation for ILS or LOC. Approach
activation, as defined for *RNAV* occurs 2 miles from the FAF. When you
select a LOC or ILS, you instead receive an advisory message cautioning
you that RNAV is for monitoring only.

Thomas Borchert wrote:

> Sam,
>
>
>>When you
>>select a LOC or ILS, you instead receive an advisory message cautioning
>>you that RNAV is for monitoring only.
>>
>
>
> Yes, but you can (and should, per the manual) activate them. So the
> question remains, what exactly does that do? In my experience, it starts
> both sequencing of the waypoints in the procedure and the change in CDI
> sensitivity. And from my experience, same goes for an RNAV approach. The
> 430 just continues to fly the original flightplan if you don't make it fly
> the approach - by activating it.
>
>
>
I agree that the manual says to activate a previously loaded approach.
But, it is overkill and unnecessary.

En route to terminal sensitivity occurs when passing within 30 miles of
the airport reference approach, whether or not an approach is loaded.,
*provided* the destination airport is the final waypoing in the flight plan.

Once flying an approach it will activate (approach sensitivity and
approach RAIM) when reasonably on course and passing inbound 2 miles
prior to the FAF.

You can hit the "activate approach" option all day long once on an
approach flight plan and inside the IAF, and nothing will happen until
you reach 2 miles from the FAF. And, the same will happen at 2 miles
from the FAF without ever pressing the "activate approach" option.

Try it in the trainer on any RNAV (GPS) IAP (or overlay IAP).

On Sat, 16 Feb 2008 14:17:02 -0800, Sam Spade <sam@coldmail.com>
wrote:


>I agree that the manual says to activate a previously loaded approach.
>But, it is overkill and unnecessary.
>
>En route to terminal sensitivity occurs when passing within 30 miles of
>the airport reference approach, whether or not an approach is loaded.,
>*provided* the destination airport is the final waypoing in the flight plan.
>
>Once flying an approach it will activate (approach sensitivity and
>approach RAIM) when reasonably on course and passing inbound 2 miles
>prior to the FAF.
>
>You can hit the "activate approach" option all day long once on an
>approach flight plan and inside the IAF, and nothing will happen until
>you reach 2 miles from the FAF. And, the same will happen at 2 miles
>from the FAF without ever pressing the "activate approach" option.
>
>Try it in the trainer on any RNAV (GPS) IAP (or overlay IAP).


Thanks Sam. Your response agrees with my simulator observations and
clears up my confusion.

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" <sam@coldmail.com> wrote in message
news:aI_tj.2986$f8.2877@newsfe23.lga...
> 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.