Garmin 530 Question

[tdawe]

Question for people out there with more Garmin 530 experience then me. Had an odd thing happen to us the other day, I've never seen it in the 3 years I've been using the units, but I'm sure I'm missing something simple, so here goes:

Flying a GPS RNAV approach, loaded and activated the approach, confirmed that RAIM was available, and at no point in the approach did we receive any "INTEG" warnings. CDI was centered throughout the approach (every once in a while I do manage a nice looking approach, honest!) However 2nm back from the FAF instead of switching from "Term" sensitivity to "APR" we got a message informing us that "Approach mode did not activate" (or something to that effect, can't remember what it said exactly) and the unit stayed in "Term" sensitivity. We checked the Satellite status page and we had a full set of satellites, all with solid bars and strong signals.

Later on that day we conducted the exact same approach, followed all the same steps as the first approach, however this time the unit went into approach sensitivity exactly as expected.

Anyone ever seen this? Do we have a possibly bunk 530? or am I missing something? Its not a WAAS unit, if that matters.

[intruder-flight]

Hmmm,

From my experience with the 430, I had the same thing happen to me a few times.

A possible explanation would be that sometimes you get to choose where you start the approach itself, VECTORS, IAF, or direct to a specific point, such as the FAF. Depending on which waypoint you choose, if you don't choose one particular it waypoint or fix, it can fail to capture any waypoint sometimes beyond the FAF to final.

For example, sometimes you may choose direct TO the FAF, it will navigate from present position direct to the fix you enter, in this case the FAF, then go into APPR Mode. But if you choose another fix, such as an IAWP, but you decide to proceed direct to the FAF instead of flying to the IAWP you entered into the GPS, the the GPS will never capture the point from your FAF to final, because the GPS expects you to fly to the IAWP first, then to the FAF to the RWY.

That is my guess.

Cheers, I-F

[Tim]

ive seen it happen a few times as well. every time it's happened to me i have corrected it by either activating vectors to final (must be done prior to the FAF) or hitting the OBS button when 'susp' is visable above it (which activates a suspended appch, or takes you to the MAP.)

i think every time this has happened to me i have been on the other side of the airport from the FAF when i loaded the appch and it was loaded as vectors to final as opposed to the full appch. if you load vectors from the oppsite side to where the appch begins i think you'll always see 'susp' above the OBS button IIRC.

[crooked timber]

However 2nm back from the FAF instead of switching from "Term" sensitivity to "APR" we got a message informing us that "Approach mode did not activate" (or something to that effect, can't remember what it said exactly) and the unit stayed in "Term" sensitivity.

did the unit sequence properly to the next wpt/rwy after the faf?

[tdawe]

Yes, I assumed if the thing was smart enough to know that it was not in the right sensitivity mode it would tell us to conduct a missed, but it just kept right on going to the next two step-down waypoints, and then the missed approach waypoint as though it was a normal approach.

Thats what I don't get, its smart enough to know its in the wrong mode, but not smart enough to switch?

[Guilden]

I know the problem, you neglected to remove the unit and send it away for WAAS capability.

[Tim]

Yes, I assumed if the thing was smart enough to know that it was not in the right sensitivity mode it would tell us to conduct a missed, but it just kept right on going to the next two step-down waypoints, and then the missed approach waypoint as though it was a normal approach.

Thats what I don't get, its smart enough to know its in the wrong mode, but not smart enough to switch?

the garmin will not cycle to the MAP until you cross the MAWP, regardless of the sensitivity. to get around this you can go into the flight plan, cycle down the MAP and go direct to that waypoint.

here's the manual
http://www8.garmin.com/manuals/2889_Pil ... erence.pdf

i would GUESS that the reason it didn't take your straight to the MAP would be because on some appch's skipping waypoints could take you into an area that wasn't assessed for obstacle clearance, especially if you were still somewhere on the 'T' part of the appch or if it the appch or MAWP was not lined up with the runway (it doesn't sound like the case for you, but that's my guess)

[Fresh Prince of King Air]

the garmin will not cycle to the MAP until you cross the MAWP, regardless of the sensitivity. to get around this you can go into the flight plan, cycle down the MAP and go direct to that waypoint.

Once you have passed the MAWP the unit will go into SUSP on the MAWP. If you want to conduct a missed approach you need only to hit the OBS button once. Which will place the unit back into LEG mode and sequence to the next waypoint.

Going into the flight plan and selecting the MAP works but is tedious.

[Ref Plus 10]

On the Garmin 530, if you have not "Activated" the approach, by going to the flight plan and actually selecting either "Activate Approach" or "Activate Vectors-To-Final", the unit will not progress the CDI scale to the requisite 0.3nm, and will warn you of such a condition upon arriving at the FAWP. It will continue to navigate along the flight plan, to the MAWP, and will then, as with all Garmin units, SUSP until such time as the SUSP is cancelled and will navigate to the next point.

Nothing to do with WAAS, just an ID10T error. If you're going to be flying IFR with a GPS, please for the love of god know how it works...

[Tim]

On the Garmin 530, if you have not "Activated" the approach, by going to the flight plan and actually selecting either "Activate Approach" or "Activate Vectors-To-Final", the unit will not progress the CDI scale to the requisite 0.3nm, and will warn you of such a condition upon arriving at the FAWP. It will continue to navigate along the flight plan, to the MAWP, and will then, as with all Garmin units, SUSP until such time as the SUSP is cancelled and will navigate to the next point.

Nothing to do with WAAS, just an ID10T error. If you're going to be flying IFR with a GPS, please for the love of god know how it works...

read what he wrote. you can't get to the FAF on an RNAV appch with having first loaded said appch unless you manually navigate direct to. not to mention he said he loaded, activated it and confirmed the RAIM.

since the GPS was not WAAS capable, i think we all figured out it was not a WAAS issue. in your haste to post a smart ass comment, maybe you forgot to understand what he was saying.

[Ref Plus 10]

Tim: Not trying to be a smartass, I apologize for overlooking several points in the OP's question.

[crooked timber]

Yes, I assumed if the thing was smart enough to know that it was not in the right sensitivity mode it would tell us to conduct a missed, but it just kept right on going to the next two step-down waypoints, and then the missed approach waypoint as though it was a normal approach.

Thats what I don't get, its smart enough to know its in the wrong mode, but not smart enough to switch?

bizarre. presuming you intercepted final outside of 2nm from the faf and crossed it without anydeflection, i don't know why it would have did what it did on an rnav approach (cdi does not autorange on back courses).

[Doc]

We just put the 530 in one of our 200's. The second one is being outfitted with a 530 as we speak. Good to see an intelligent discussion on a subject we might actually learn something from.

[tdawe]

Give it time, it'll degenerate, they all do..

Emailed Garmin, hopefully they'll have some sort of answer in the next few days.