Garmin 430/530 Flight Plan and IAP sequencing

[robertb]

Hello all,
I am pretty sure this would have been discussed before, but I couldn't find it using the search tool. So...

Let's say I want to fly from KSEE to KRNM IRF with a Garmin GNS430 or 530 unit, I load a basic flight plan before takeoff based on the clearance of KSEE, Right Turn 340, RV JLI VOR, KRNM. I then add KRNM's RNAV (GPS)-B approach (it has only one IAF which is JLI) to the flight plan and "load approach". So, the flight plan in the unit is:

KSEE
JLI
KRNM
--- RNAV-B Approach
JLI (IA)
MEDDI
RICCE (FA)
ENOBE
DICER (MA)
HERDS
ROBNN

If someone were to be happily flying this route on the leg from KSEE to JLI (for discussion's sake, lets assume inbound direction to JLI didn't a procedure turn) and not select the second JLI in their flight plan when being cleared direct to JLI, the GPS would sequence directly from JLI to KRNM and ignore the step down fixes, not enter approach mode before RICCE, and cause a bunch of confusion.

To me, it seems like it would be nice if the Garmin would insert the approach PRIOR to the destination airport instead of after. But, I didn't design the unit and hope there is a logical reason why it was built as it is.

So, when adding an approach to a destination airport, do others:

1. Remove the desitination airport from the flight plan once an approach to that airport is loaded?
2. Remove the desitination airport from the flight plan and add it after the approach once an approach to that airport is loaded?
3. Manually activate the correct leg or fix when appropriate? (Ie, if cleared "direct JLI" shortly after takeoff, activate the second JLI in the flight plan so sequencing is correct.)
4. Have a far better method than the above that I should be aware of and aren't? (I hope this is the answer, btw.)

Thanks in advance gang!

 

[midlifeflyer]

So, when adding an approach to a destination airport, do others:

1. Remove the desitination airport from the flight plan once an approach to that airport is loaded?

No. I'm still going to the airport.

2. Remove the desitination airport from the flight plan and add it after the approach once an approach to that airport is loaded?

No. Why? DICER is the runway edge. Why do I need the airport after it?

3. Manually activate the correct leg or fix when appropriate? (Ie, if cleared "direct JLI" shortly after takeoff, activate the second JLI in the flight plan so sequencing is correct.)

I would not do it until I was at least in the approach environment and told to expect that approach. Definitely not right after departure. (I sometimes load an approach before departure), but ultimately, yes.

4. Have a far better method than the above that I should be aware of and aren't? (I hope this is the answer, btw.)

It's clearly not the only way to do it, IIRC, Avidyne merges the waypoints if they follow each other). But don't have a problem with the approach being loaded as part of an approach sequence that I might or might not use, leaving the original flight plan intact for the possibility of amendment before the approach sequence.

and cause a bunch of confusion.

There's no reason to cause confusion unless you are not paying attention to the flight plan and letting the plane do what it wants.

 

[RussR]

The issue is that until you are cleared for the APPROACH, you are NOT cleared to those other fixes. Your clearance is from JLI straight to the airport, and that's the route you need to fly. On your way there, the weather may change, runway or approach in use changes, or just the routing changes. So you don't want to proceed to the second JLI (and therefore the rest of the approach fixes) until you're cleared for the approach. That's why the division is there, and that's common for all FMS and GPS units that I'm familiar with.

Besides, until you get the ATIS and talk to the approach controller, you're never sure which approach or entry you're actually going to get. On non-training flights, it's not common to load the approach before takeoff like we often get away with on training flights. You wait until you're closer to your destination to do that, so you have the current information.

 

[edo2000]

Hello all,
I am pretty sure this would have been discussed before..

Even so. A good discussion. Much appreciated. I recently purchased an aircraft with 2 GNS-430Ws. I want to hear anything that @midlifeflyer @RussR and other experienced folks have to say on their operation. One day, it will all make sense...

 

[midlifeflyer]

I recently purchased an aircraft with 2 GNS-430Ws.

I hope you are getting some good training on their use. People throw around the word "intuitive" all the time, but I think of intuitive as a feature of the person, not the equipment, and, when it's new, usually neither definition applies.

Central Colorado ... we talking Buena Vista?

 

[RussR]

Even so. A good discussion. Much appreciated. I recently purchased an aircraft with 2 GNS-430Ws. I want to hear anything that @midlifeflyer @RussR and other experienced folks have to say on their operation. One day, it will all make sense...

The 430W is still an extremely capable unit. Unfortunately, it's literally a 30-year old design (the 430 was first available in 1998) with a look and feel that is very much from that era - in addition to things like not having airways because back then everybody assumed airways were going away with GPS.

Fortunately, though, since it's 30 years old it benefits from a TON of training materials. Endless books, videos, articles. There are so many that are installed that virtually every active CFI has experience with them.

However, this also means that almost everybody feels like they know how to use them, when in reality (like I believe Mark will certainly attest to), they really only know the basics. So get yourself good instruction to avoid developing bad habits (like the whole vectors-to-final issue).

 

[edo2000]

I hope you are getting some good training on their use. People throw around the word "intuitive" all the time, but I think of intuitive as a feature of the person, not the equipment, and, when it's new, usually neither definition applies.

Central Colorado ... we talking Buena Vista?

Yeah at this point, the nav side of these units are pretty much opposite of intuitive, to my brain(comm side seems pretty easy to use). Direct To works pretty well . I flew a lot of IFR when I was younger, using VOR, ILS, and even some ADF navigation, keeping my Jepp charts up to date, etc. But all VFR, in the past couple of decades. That was how my last few aircraft were equipped. Now, I have a Bonanza with an EFIS(Aspen) and dual 430s... and yes, I plan to be doing a considerable amount of training on the new aircraft and avionics. My work schedule has been a bit of an obstacle so far.

Close to BV ... Salida. Thanks again, guys. Please keep sharing your wisdom.

 

[Let'sgoflying!]

Austin yesterday, had a route like yours with the approach they told me to expect Loaded but not Activated (ILS 18L).
So I was going to a fix (Houkm) on the arrival (which led into the approach).
Why not activate, or fly to the same fix on the approach?
Well, Austin.
Controller decided too many planes on 18L so switches me ~3 minutes out to 18R.
f.u.@#&!
Actually I was ready because they’ve done this before, last minute runway change in bumpy clouds, lotsa traffic.
Removed 18L, put in 18R, all the while the plane is still tracking the arrival just fine.
If I had previously selected the fix on the 18L approach, I’m not sure the plane would know where to go when I removed 18L, probably coast I guess.
So, don’t start flying something they haven’t given you yet, don’t get too far ahead of the game.

 

[midlifeflyer]

Close to BV ... Salida

Nice place.

 

[JVerb]

Like a couple others said, the reason the gps nav units put the approach AFTER reaching the airport is because they're mostly just banking them in their memory for the moment. Your clearance by ATC is to the particular airport. The approach waypoints are not in your flight plan until you are cleared to fly to them. This is what the "activate approach" option is for. As soon as you are cleared to fly them, you can activate the approach and it will immediately put them as the next destination. You can also do it by pulling up the flight plan, highlighting the first approach fix, and hitting direct-to enter-enter for it. That will then start sequencing through them as well.

If the units put the approach directly in front of the airport, the flight plan ATC expects you to take and the direction you'd be going, would be wildly different depending on the approach. Imagine if you went direct to a standard "T" IAP when ATC expected you to be flying direct to the airport like your clearance told you to. Your autopilot (or your brain/hands) would take you several miles off course of your route if you're going to the IAP instead.

 

[midlifeflyer]

This is what the "activate approach" option is for.

Yes, the "activate approach" option is one of the ways to initiate approach waypoint sequencing. But as we recently discuss here, it's unnecessary and can potentially get you in trouble since the only thing it does is send you direct to the transition you chose when you loaded the approach, even if it's behind you now.

 

[flyingcheesehead]

To me, it seems like it would be nice if the Garmin would insert the approach PRIOR to the destination airport instead of after. But, I didn't design the unit and hope there is a logical reason why it was built as it is.

Because you're generally not cleared for the approach until well after takeoff. Also, consider the case where your clearance doesn't include an IAF - For example, if instead of JLI you were cleared via CHEEF. Upon reaching CHEEF, if you haven't received any changes to your clearance, do you turn towards the airport, or do you turn towards JLI? You turn towards the airport, because that's where you're cleared to. You're not cleared for the approach until you're cleared for the approach.

So, when adding an approach to a destination airport, do others:

1. Remove the desitination airport from the flight plan once an approach to that airport is loaded?

Nope. I'm still going there... And in your case, you're still cleared from KSEE to JLI to KRNM until you're cleared for the approach.

2. Remove the desitination airport from the flight plan and add it after the approach once an approach to that airport is loaded?

Not really necessary - By the time you get to the MAP, you've got to have eyes on the airport so you shouldn't need the GPS any more at that point.

3. Manually activate the correct leg or fix when appropriate? (Ie, if cleared "direct JLI" shortly after takeoff, activate the second JLI in the flight plan so sequencing is correct.)

Nope - Again, your clearance doesn't include the approach until you're cleared for the approach. You want to be going to the first JLI until you're cleared for the approach.

4. Have a far better method than the above that I should be aware of and aren't? (I hope this is the answer, btw.)

You're good - Just load the approach, fly the plan, and when you're cleared for the approach you can a) activate a leg you plan to intercept, b) activate the approach if you're going to do full procedure from the IAF, or c) activate vectors to final if appropriate (which is really just a form of a).

 

[midlifeflyer]

b) activate the approach if you're going to do full procedure from the IAF, or c) activate vectors to final if appropriate

Neither of which are necessary and both of which are actively avoided by many pilots. One of those technique things that are part of a good training regimen - not avoiding them, but (following the theme of this thread) understanding the options so one can make an SOP decision about their use.

 

[flyingcheesehead]

Neither of which are necessary and both of which are actively avoided by many pilots. One of those technique things that are part of a good training regimen - not avoiding them, but (following the theme of this thread) understanding the options so one can make an SOP decision about their use.

Yep... You need to understand the box and make it do what you want, which certainly means understanding what those options do. If I were given direct to the IAF after getting cleared for the approach, I know that I can do that either by activating the approach or by going direct to the fix the second time it appears - But there's a potential for error there since it appears in the plan twice, so in that case I'd activate the approach. And if I'm inside the IF and given vectors, I think I can activate VTF faster than I can activate the intermediate leg, which are functionally equivalent at that point, so...

But yes, it would be a very good idea for the OP to read all the other threads here, and posts/articles from others all over the Internet talking about what activating an approach or VTF on a Garmin box actually does.

 

[Hang 4]

But yes, it would be a very good idea for the OP to read all the other threads here, and posts/articles from others all over the Internet talking about what activating an approach or VTF on a Garmin box actually does.

Also important to not just say "Garmin" box. Differences between GTN and 4/530 boxes. Similar logic on both, but a bit more flexibility on GTN.