Garmin 430 and ILS
Greg Esres
guidance on an ILS/LOC up until the final approach fix. Where exactly
does the approval for this come from? My inclination would have been
that in absence of an overlay, you could not use GPS anywhere after
the IAF.
Also, assuming this approval is legit, shouldn't this extend to a
non-overlay VOR approach?
T...@backhome.org
Greg Esres wrote:
> The Garmin 430 documentation says that you can use the GPS for course
> guidance on an ILS/LOC up until the final approach fix. Where exactly
> does the approval for this come from? My inclination would have been
> that in absence of an overlay, you could not use GPS anywhere after
> the IAF.
>
Garmin is correct. You don't need approach RAIM or approach sensitivity
until the beginning of a final approach segment for either a stand-alone
RNAV approach or an approved overlay.
So, you do not need localizer guidance until the P-FAF for an ILS approach
or the NPA FAF for a localizer approach. Because overlay is not approved
for a localizer, the localizer itself has to be used for the ILS or
localizer final approach segment.
The "flip-side" is also true, which is what Garmin states.
>
> Also, assuming this approval is legit, shouldn't this extend to a
> non-overlay VOR approach?
True, it could, but the vendors haven't seen that as a real-world issue.
Greg Esres
sensitivity until the beginning of a final approach segment >>
I was sure they were, but I'm concerned about how to demonstrate this
correctness to others. The AIM says nothing about this.
I accept that flying the localizer outbound for the PT does not
require approach sensitivity and that the protected area is wide on
the initial segment, but I shouldn't have to know these things in
order to know what I can do with this box.
I'm mostly concerned with checkrides. Is there anything other than
Garmin documentation that can demonstrate this is a legal thing to do?
<<"re: non-overlay VOR approach?" True, it could, but the vendors
haven't seen that as a real-world issue.>>
I haven't done this in the real airplane, but on the simulator, the
box will advise changing to Vloc once established on the inbound
course of a VOR, but will not switch over. In fact, it goes down to
approach sensitivity, but doesn't indicate approach RAIM.
Would you argue that using the GPS for course guidance up to this
point is legal?
Thanks!
T...@backhome.org
Greg Esres wrote:
If you can retrieve it from a current database with an IFR
approach-approved GPS, it is legal to use. You will note the warning
message Garmin provides when you pull up and ILS approach.
Greg Esres
Not really on target.
The issue is using GPS as your primary source of navigation on an
instument approach.
Greg Esres
and ILS approach.>>
Yes, and I consider it to contradict what the manual says. The note
says for "monitoring" only, insinuating that approach guidance needs
to come from the underlying navaid at all times.
That's part of the reason I asked the question. I have difficulty
explaining away the inconsistency between the note and the
permissiveness of the manual.
Greg Esres
My understanding is that an IFR GPS always has RAIM, if the geometry
of the satellites permits. Approach RAIM just has narrower
tolerances.
Peter Clark
wrote:
Same issues I'm attempting to work through in my thread "Yet more GPS
substitution questions", cept I was looking at a VOR/DME. I'll just
merge into this one - thanks.
T...@backhome.org
Greg Esres wrote:
You should discuss that with Garmin. The restriction is meant to apply
to the final approach segment only. It doesn't bother me because I know
it's the same for FMS/LNAV in a 777 or a Garmin 430 in a Cessna 182.
You are using terminal mode except for the final approach segment.
Jose
>
> [...] If the VOR happens
> to be off a degree or two, and indicates a turn in one direction, and
> the GPS indicates a turn in then other direction, that the pilot must
> follow the "primary" device, even though it's indicating the wrong
> thing?
Yes, I think so. If you have two devices with contrary indications, you
need to decide which to believe. If an accident occurs because you
believed the GPS (and it was wrong) the FAA busts you for not following
rules. IF an accident occurs because you believed the ADF, the FAA
busts you for being careless and reckless.
:) Jose
Greg Esres
<<What exactly does "primary source" mean, anyway...
It's a bunch of baloney, once you start thinking about it>>
What I mean is that you're not looking at the underlying navaid *at
all.* Not turned in.
Greg Esres
'Cause the 430 is all I have. (not really, but for the sake of
argument.)
Greg Esres
I've sent them an email, but I'm skeptical of receiving a coherent
response. ;-)
Greg Esres
approach-approved GPS, it is legal to use. You will note the warning
message Garmin provides when you pull up and ILS approach.>>
I checked with the AIM again, and what it says seems on point:
<-------Snip------>
Do not attempt to fly an approach unless the procedure is...identified
as "GPS" on the approach chart...The navigation database may contain
information about nonoverlay approach procedures that is intended to
be used to enhance position orientation, generally by providing a map,
while flying these approaches using conventional NAVAIDs.
<-------Snip----->
Garmin's position, as you know, is that you aren't "established" on
the approach until you're on final. Are you aware of any
justification for this position at all?
(Yes, I have asked Garmin the same thing, but haven't received an
answer yet.)
T...@backhome.org
Greg Esres wrote:
I think I have covered it, but let me try again: for purposes of TERPS
and regulatory requirements to be established, an IAP can begin as early
as a feeder fix (before an IAF, where there is a feeder fix).
For purposes of the specifications for IFR GPS avionics, the "approach" is
*only* the final approach segment. The other segments are terminal
routes, and use terminal CDI scaling/sensitivity/RAIM. Only the approach
mode uses approach scaling/sensitivity/RAIM.
You won't find a regulation that says this, nor will you find an FAA
document that proclaims this to pilots. Nonetheless, all TSO-C129
avionics and all higher-end LNAV/FMS platform treat the final approach
segment as the "approach," per se.
Stan Prevost
<T...@Backhome.org> wrote in message news:4213B4AA...@Backhome.org...
>
> You won't find a regulation that says this, nor will you find an FAA
> document that proclaims this to pilots. Nonetheless, all TSO-C129
> avionics and all higher-end LNAV/FMS platform treat the final approach
> segment as the "approach," per se.
>
The AIM sorta kinda maybe alludes to it when talking about WAAS units.
" The pilot enters a unique 5-digit number provided on the approach chart,
and the receiver recalls the matching final approach segment from the
aircraft database. ....... The pilot should confirm that the correct final
approach segment was loaded by cross checking the Approach ID, which is also
provided on the approach chart. "
Matt Barrow
<T...@Backhome.org> wrote in message news:4213B4AA...@Backhome.org...
>
>
> and regulatory requirements to be established, an IAP can begin as early
> as a feeder fix (before an IAF, where there is a feeder fix).
Example : GUMLE at Juneau (JNU) GPS V RWY 8.
http://204.108.4.16/d-tpp/0501/01191RV8.PDF
Greg Esres
"approach" is *only* the final approach segment. The other segments
are terminal routes, and use terminal CDI scaling/sensitivity/RAIM.
Only the approach mode uses approach scaling/sensitivity/RAIM.>>
None of that is relevant. You're talking about how this stuff is
stored in the database.
The directive to pilots is that only approaches labeled "GPS" can be
flown with GPS. The word "approach" clearly refers to a pilot's
understanding of what an approach is.
Got a phone number for the guys that write this section in the AIM?
cfey...@nowhere.org
wrote:
>The directive to pilots is that only approaches labeled "GPS" can be
>flown with GPS.
What does this mean, exactly?
Must I turn off my GPS if I am flying a VOR or NDB approach?
Will I lose my certificate if I look at my GPS during the approach?
Will I lose my certificate if I look at the GPS more than I do the
OBS/ADF?
These generalized statements one finds in the AIM and elsewhere need
to be examined for specific meanings. When that is done, one finds
that most of them are absolute garbage.
T...@backhome.org
Greg Esres wrote:
> <<For purposes of the specifications for IFR GPS avionics, the
> "approach" is *only* the final approach segment. The other segments
> are terminal routes, and use terminal CDI scaling/sensitivity/RAIM.
> Only the approach mode uses approach scaling/sensitivity/RAIM.>>
>
> None of that is relevant. You're talking about how this stuff is
> stored in the database.
No, we were talking about how Garmin posts a cautionary note about not
using GPS for the final approach segment of an ILS or localizer type
IAP.
>
>
> The directive to pilots is that only approaches labeled "GPS" can be
> flown with GPS. The word "approach" clearly refers to a pilot's
> understanding of what an approach is.
>
> Got a phone number for the guys that write this section in the AIM?
You want to enter into a consulting agreement?
T...@backhome.org
cfey...@nowhere.org wrote:
The AIM is written by many different FAA departments. Which one it's
assigned to depends upon the subject matter. There is no broad editorial
or content oversight. It just "happens."
Industry groups have managed to get an occasional section cleaned up by
taking them to the semi-annual Aeronautical Charting Forum (FAA/Industry
meeting in DC area) and laborously working the issue. It's not easy.
(You could submit your concerns to AOPA and ask that they submit it to
the Aeronautical Charting Forum. That would require that AOPA show up,
though, which they don't often do.)
The FAA is a federal agency that is fractured and dysfunctional in the
best of times. Since 911 the budget pressures on them have been
awesome. The controller workforce is trying to grab more and more of a
shrinking pie. The airports funding has been robbed by the White House
budget managers. This week's Aviation Week has a good editorial about it
all.
Bottom line: Don't expect this stuff to get better.
Off subject a bit: I hope I am wrong, but I expect WAAS to disappear
within a few years. None of the smart money is chasing WAAS. New
high-end biz jets are coming off the line today with no WAAS capibility
installed or planned. They are betting on GPS and Baro VNAV (requires
GPS only) or ILS.
Roy Smith
cfey...@nowhere.org wrote:
The AIM recommends that any unauthorized instruments have their displays
covered with a ham sandwich when passing the final approach fix.
cfey...@nowhere.org
I don't believe this is true.
It has been demonstrated that some people navigate better with a ham
sandwich than they can with either ADF or VOR. Therefore the ham
sandwich would also be illegal.
Roy Smith
Greg Esres
not using GPS for the final approach segment of an ILS or localizer
type IAP.
That isn't what it says. Here it is verbatim:
"GPS guidance is for monitoring only. Activate approach?"
It says nothing here about "final approach." How could this be more
clear?
<<You want to enter into a consulting agreement?>>
For a phone number? Harsh. ;-)
Greg Esres
to be examined for specific meanings. When that is done, one finds
that most of them are absolute garbage.>>
If you're deliberately being obtuse.
The AIM is clear that you may not use GPS for flying LOC, ILS, SDF and
non-overly approaches using the GPS as your primary means of
navigation. You must be monitoring the underlying navaid.
T...@backhome.org
Greg Esres wrote:
> <<No, we were talking about how Garmin posts a cautionary note about
> not using GPS for the final approach segment of an ILS or localizer
> type IAP.
>
> That isn't what it says. Here it is verbatim:
>
> "GPS guidance is for monitoring only. Activate approach?"
>
> It says nothing here about "final approach." How could this be more
> clear?
"Activate *approach*" in GPS paralance means the final approach
segment. If you can get Approach Mode active for other than the final
approach segment, let us know.
Greg Esres
segment. If you can get Approach Mode active for other than the final
approach segment, let us know.>>
Geez, "Activate Approach" for Garmin means to make the IAF the active
waypoint. That has nothing to do with "Approach Active".
Your answer was bullshit and you know it.
I suspect that you agree that there is no authorization to use these
boxes in this fashion and you just don't want to acknowledge it.
Greg Esres
You're trying to use semantics in order to escape from any restriction
from doing something you want to do. Teenagers are very good at this.
;-) I don't have much interest in playing this game, because your
goal isn't understanding, but winning.
As I told you in another post, this issue here is using the GPS as
your sole means of navigation on the initial segment and portions of
the intermediate segment of a non-overlay approach procedure.
T...@backhome.org
Greg Esres wrote:
Since you choose to denigrate the conversation to the use of profanity,
and further you seem to think you can read my mind, there isn't much left
in the form of an intelligent discussion. "Activate Approach" provides
both terminal routes and arms the final approach segment for Approach
Mode. That cannot happen with an ILS/LOC type procedure.
The airlines have been flying the RNAV overlays of the conventional
terminal routes on an ILS for over 20 years. They switch to LOC guidance
not later than the P-FAF, and often the IF. This practice has been
subject to considerable oversight by the FAA. Flying a terminal route
prior to the FAA is no different than flying an airway. You don't need to
be checking underlying nav facilities during such an operation.
It sounds like your both anal retentive and spring-loaded to being
unreasonably argumentative, yet you are unwilling to do your own leg work
to get to the folks in the FAA who can answer your unnecessary question.
Greg Esres
terminal routes on an ILS for over 20 years. >>
What the airlines do is irrelevant to General Aviation operations.
They're using different equipment and operating under different rules.
<<You don't need to be checking underlying nav facilities during such
an operation.>>
That's your opinion, for which you have been unable to offer
supporting evidence. The AIM says differently.
<<It sounds like your both anal retentive >>
You mean "you're". ;-) Is it anal retentive to want to follow the
law? Ok, guilty.
<<and spring-loaded to being unreasonably argumentative>>
I must admit that I find it annoying and insulting when someone tries
to pass off a series of irrelevancies and non sequiturs as an
explanation. I usually associate this with someone hiding a lack of
knowledge.
<<yet you are unwilling to do your own leg work to get to the folks in
the FAA who can answer your unnecessary question.>>
This is my own leg work. ;-) I have also exchanged emails with the
folks at Garmin, who were also unable to offer a coherent explanation
as to why I could use their equipment in this fashion.
Finding someone knowledgable at the FAA is a real chore. There also
I run into people who try to "explain" things to me, only to find out
they know less than I do on the subject.
Greg Esres
to be able to explain how you would apply them to real-life scenarios.
>>
How much clearer can I be when I say that I'm using a Garmin 430 as
the only navigation insturment turned on in the airplane.
<< (Teenagers are also very good at this.)>>
:-)
Greg Esres
He should be, since that what this thread is about.
<<If I am not mistaken, the KLN units use "APPR" mode as Garmin uses
"ACTV" when within two miles of the FAF, on the intermediate
segment.>>
Different animals. The KLN unit doesn't have the concept of "Activate
Approach."
When you load an approach on the KLN94, you then have to set the IAF
as the active waypoint. This is a separate operation.
When you load an approach on the 430, you are prompted "Activate
Approach?" If you choose it, then the IAF becomes the active
waypoint. Otherwise, the approach is simply "loaded" and you later
have to change your waypoint to the IAF, just like the KLN94.
T...@backhome.org
Greg Esres wrote:
> <<The airlines have been flying the RNAV overlays of the conventional
> terminal routes on an ILS for over 20 years. >>
>
> What the airlines do is irrelevant to General Aviation operations.
> They're using different equipment and operating under different rules.
The different equipment does pretty much the same thing as a Garmin
400/500 series, at least as to LNAV. And, the rules pertaining to air
carrier navigation in the national airspace system are the same rules you
use.
Or, if you think I am wrong, provide specifics.
T...@backhome.org
Greg Esres wrote:
>
> <<If I am not mistaken, the KLN units use "APPR" mode as Garmin uses
> "ACTV" when within two miles of the FAF, on the intermediate
> segment.>>
Gee, my Garmin goes from TERM to APR when within two miles of the FAF.
Greg Esres
wrong, provide specifics.>>
Fair question.
Hmmm...do takeoff minimums apply to me? Do they apply to airlines?
Can I shoot the approach anyway if the ATIS is reporting zero/zero
conditions? Can airlines?
Can I fly non-precision approaches using precision approach technique
(DA)? Can some approved operators?
Am I required to come up with a set of operating specifications that
govern my activities once they are approved by the FAA? Do airlines?
I have no specific information that relates to our current topic of
discussion, but there are clearly different sets of rules that apply
to Part 91 vs. 121 flyers.