Flying the magenta line?

[airdale]

This is getting very confusing, primarily because olasek and MikePapa have said some things that are just flat wrong. My current theory is that both are poseurs.

A few posts ago I commented that MikePapa's suggestion regarding Direct-To did not seem to work for plain garden-variety VTF approaches. Subsequent to that comment, the wheels seem to have come off the cart. I'll not contribute to the confusion by responding to either of them again.

gismo, to your specific questions:

... until you activate the approach the GPS will not engage approach mode scaling of the CDI ...

No, it scales down as you near your destination even if no approach is loaded. You'll see the scaling change on a plain vanilla flight plan between KABC and KXYZ. I don't remember if it goes all the way down to 0.3 mile scale or just stops at a mile.

Are we talking about flying a GPS approach or just providing "situational awareness" on some other type of approach?

For purposes of this discussion, it really doesn't matter what the approach type is. We're just talking about dealing with the waypoints.

I believe that the FAC only shows up if you are reasonably close to it (e.g. within 30 nm)

Yes. The VTF line doesn't go to infinity, but in my experience it's rare to get vectors until you get reasonably close anyway.

it's never expected that you would be vectored to the FAC inside the FAF.

No, but (digression) I have had it happen a couple of times in very windy conditions where I was coming from about 90 deg to the FAC and the controller misjudged the drift! In both cases I stupidly flew the clearance and fortunately things worked out.

 

[MikePapa]

I must admit I'm confused by this. While I'm not a frequent user of the 430W I do have some experience with them (and the simulator) and I was under the impression that until you activate the approach the GPS will not engage approach mode scaling of the CDI or validate the HPL/VPL for the approach, nor will the GPS provide guidance beyond the lines drawn on the map. What am I missing here? Are we talking about flying a GPS approach or just providing "situational awareness" on some other type of approach?

My understanding is that CDI scaling has nothing to do with whether you activate the approach or not, but rather distances from the airport, FAF, or threshold.

 

[TMetzinger]

CDI scaling does change from enroute to terminal mode (1 NM) based on your flight plan. Approach mode scaling (normally linear to .3 NM but also ANGULAR for certain approaches <LPV I believe but have to go look it up>) only occurs when an approach is loaded and active.

 

[gismo]

My understanding is that CDI scaling has nothing to do with whether you activate the approach or not, but rather distances from the airport, FAF, or threshold.

Could be but that's not what the Pilot Guide says nor is that the way TSO C146a says it's supposed to work. I suspect that it adjusts the scale down to 1 nm as you near the destination (TERM mode) but I doubt that it goes to the required .3nm scale for APR mode on LNAV type approaches and I'd really be surprised if it engaged the angular scaling on a LPV or LP unless the appproach was active. But like I said, I'm not that experienced with the 430W.

 

[MikePapa]

This is getting very confusing, primarily because olasek and MikePapa have said some things that are just flat wrong. My current theory is that both are poseurs.

Unlike you, I'm certainly open to the possibility that I'm wrong, but one thing you would greatly benefit from learning is that just because you don't agree with someone, doesn't mean they are wrong. Because you refuse to support your assertions, I strongly suspect you're the poseur here, but as far as I'm concerned it doesn't really matter. One thing for sure I've noticed from reading your few posts is that you're little more than a disruptor that's interested in little more than being argumentative and that's enough to earn you the first spot on my ignore list.

 

[MikePapa]

Could be but that's not what the Pilot Guide says nor is that the way TSO C146a says it's supposed to work. I suspect that it adjusts the scale down to 1 nm as you near the destination (TERM mode) but I doubt that it goes to the required .3nm scale for APR mode on LNAV type approaches and I'd really be surprised if it engaged the angular scaling on a LPV or LP unless the appproach was active. But like I said, I'm not that experienced with the 430W.

I don't know of anything in the TSO that says the approach has to be activated for CDI scaling to occur and that's not what Max Trescott teaches who has literally wrote the book on the subject (actually two very good ones). Hopefully he'll take note of this thread and shed some light on the subject.

 

[TMetzinger]

While I have met Max and spoken with him several times, it's possible that he may have made a mistake or (more likely) you may have misinterpreted what he wrote.

If you have an approach as part of your flight plan, the G1000 sensitivity will scale as appropriate for the approach procedure. If you do not have an approach loaded, it will scale to terminal sensitivity but will not alter scale beyond that. I have confirmed this with the latest G1000 sim (flew direct to an airport on a flight plan with no approach, then loaded an approach and flew that) and careful attention to the reference manuals.

 

[olasek]

My understanding is that CDI scaling has nothing to do with whether you activate the approach or not, but rather distances from the airport, FAF, or threshold.

I agree with you 100%. Sensitivity CDI scaling has absolutely nothing to do with pilot activating the approach manually. Max Trescott during the seminar I mentioned above explained very clearly what activation does (and no, we understood very clearly what was said, there was no ambiguity). The only thing that manual activation does is to draw magenta line from your current position to the IAF of your approach, making IAF your active waypoint (equivalently for activating VTF). Max even joked about some of his pilots-students who insisted in flight on activating approach. You can activate approach while being 100 nm from the airport if this is your fancy. The Garmin unit is smart enough to figure out that change of sensitivity is needed purely based on where you are.

 

[MikePapa]

While I have met Max and spoken with him several times, it's possible that he may have made a mistake or (more likely) you may have misinterpreted what he wrote.

If you have an approach as part of your flight plan, the G1000 sensitivity will scale as appropriate for the approach procedure. If you do not have an approach loaded, it will scale to terminal sensitivity but will not alter scale beyond that. I have confirmed this with the latest G1000 sim (flew direct to an airport on a flight plan with no approach, then loaded an approach and flew that) and careful attention to the reference manuals.

You haven't contradicted me. My contention is the approach does not have to be activated for scaling to occur. Obviously an approach has to be loaded into the flight plan and I took that as a given. If the approach weren't loaded the system would scale to terminal mode (because that relies on the distance to the destination airport), but it would have no idea what the FAF is or any other fix on the approach you're flying.

 

[TMetzinger]

I agree with you 100%. Sensitivity CDI scaling has absolutely nothing to do with pilot activating the approach manually. Max Trescott during the seminar I mentioned above explained very clearly what activation does (and no, we understood very claery what was said, there was no ambiguity). Max even joked about some of his students who insisted in flight on activating approach. The only thing that manual activation does is to draw magenta line from your current position to the IAF of your approach. You can activate approach while being 100 nm from the airport if this is your fancy. The Garmin unit is smart enough to figure out that change of sensitivity is needed based on where you are.

Whoops, two different things. CDI scaling has to do with having an approach loaded and active. No approach, no scaling beyond terminal sensitivity.

Example - KJYO-KOKV. Flight plan is KJYO-LUCKE-KOKV. En route to LUCKE, you get told to expect the VOR-A approach from MRB, so you LOAD the approach and select MRB as the IAF. You only LOAD the approach, not activate it, by selecting the load approach button.

As you near LUCKE, look at the MAP and flight plan - your next waypoint after LUCKE is KOKV, because the approach is loaded but not active.

Unless you ACTIVATE the approach, your system will steer you to KOKV. Once you ACTIVATE the approach, you're headed for MRB, and then scaling and such happens automatically.

Now, if my original flight plan had been KJYO-LUCKE-MRB-KOKV, and then I loaded the VOR-A approach with MRB as the IAF, what happens? Nothing different - unless I activate the approach, my next waypoint after MRB will be KOKV, not the approach waypoints.

Since I'll be flying this week I'll confirm it in the real airplane. But to my knowledge, you must always activate an approach in the G1000. You can load and activate it in one operation, but if you preload it, you must still activate it later.

 

[TMetzinger]

You haven't contradicted me. My contention is the approach does not have to be activated for scaling to occur. Obviously an approach has to be loaded into the flight plan and I took that as a given. If the approach weren't loaded the system would scale to terminal mode (because that relies on the distance to the destination airport), but it would have no idea what the FAF is or any other fix on the approach you're flying.

OK, let me be more clear.

Scaling between terminal and enroute sensitivities (both directions) happens automatically.

Scaling to an approach sensitivity requires an approach to be loaded and active.

Still agree?

 

[TMetzinger]

There's no requirement to activate the approach and in some cases doing so will get you in trouble if you are not certain where you are going. Once the approach is loaded you can select any fix on the approach, select direct-to, and away you go. Once you get on the approach everything will sequence as it should and you can legally fly the whole approach without "activating" anything. The only real advantage to activating an approach is it saves a very small amount of time spent on keystrokes so long as whatever you're activating is where you want to go. If ATC directs you to something other than a IAF or a FAF, activating the approach will actually take more time because you're then going to have to do a direct-to anyway.

Personally I very rarely, if ever, activate the approach because I always want to be sure where I am going. It's worth the extra keystroke or two to me to double check what fix I am navigating towards. That's where people get into trouble with the magenta line. They might know where they are, but they don't know where they are going, which is equally as important.

I think this is where the confusion started.

You have to get to the approach in your flight plan by either:

• Activating it
• Picking a waypoint from the loaded approach section of the flight plan, and hitting direct-to. This activates the approach mode (by the way) and takes you direct to the chosen waypoint.

 

[gismo]

I don't know of anything in the TSO that says the approach has to be activated for CDI scaling to occur and that's not what Max Trescott teaches who has literally wrote the book on the subject (actually two very good ones). Hopefully he'll take note of this thread and shed some light on the subject.

Well, I tried an approach on the 430W simulator and it does indeed adjust the CDI scale appropriately whether or not the approach is "activated" so it appears that I was wrong. I guess "Loading" the approach is sufficient to fly it as long as you don't mind flying to the airport before beginning the approach. And WRT the TSO it actually just says the CDI scaling must adjust to .3 nm by the time the FAF is reached, it doesn't say anything about "activating" vs "loading" the approach.

 

[Palmpilot]

I think this is where the confusion started.




You have to get to the approach in your flight plan by either:

• Activating it
• Picking a waypoint from the loaded approach section of the flight plan, and hitting direct-to. This activates the approach mode (by the way) and takes you direct to the chosen waypoint.

I was just experimenting with the 400 series simulator, and if the thing is correct, there is another way to get to the approach. I found that if there is no active flight plan and no direct-to course active, then loading a flight plan causes it to take me direct to the IAF I selected. So it appears that the only thing manual activation does is to make it skip over any flight plan waypoints that are not part of the approach. However I haven't experimented with VTF or procedure turns yet.

 

[olasek]

But to my knowledge, you must always activate an approach in the G1000.
....

Like I said before argue this with Max, my experience with PC trainer shows it is absolutely not necessary and confirms only what Max said. Later you seem to be stating that approach must be active, which I agree with, but this is different than saying pilot must manually activate it. I hope we are approaching the crux of the matter....

we are getting even closer here ...

You have to get to the approach in your flight plan by either:

• Activating it
• Picking a waypoint from the loaded approach section of the flight plan, and hitting direct-to.

OK, but you failed to mention the third and the most obvious case - namely doing nothing, no activation, no direct-tos, just following your flight plan with a preloaded approach waypoint by waypoint - is certainly a way to get to the approach.


EDIT: Tim, I re-read your previous post, specifically this: As you near LUCKE, look at the MAP and flight plan - your next waypoint after LUCKE is KOKV, because the approach is loaded but not active..
.. Consider it Garmin's philosophy of flight planning - they like the idea of heading in the direction of the airport first and worry about any approach later. But nothing prevents you from deleting KOKV before you even take off or alternatively you can leave it (and overfly the airport before approach) - no matter what you do the G1000 will sequence you through the flight plan of your choice and will eventually get you through the approach with the required sensitivity. So your example shows rather a quirk in the flight planning than a real need for manual activation.

 

[TMetzinger]

EDIT: Tim, I re-read your previous post, specifically this: As you near LUCKE, look at the MAP and flight plan - your next waypoint after LUCKE is KOKV, because the approach is loaded but not active..
.. Consider it Garmin's philosophy of flight planning - they like the idea of heading in the direction of the airport first and worry about any approach later. But nothing prevents you from deleting KOKV before you even take off or alternatively you can leave it (and overfly the airport before approach) - no matter what you do the G1000 will sequence you through the flight plan of your choice and will eventually get you through the approach with the required sensitivity. So your example shows rather a quirk in the flight planning than a real need for manual activation.

To me this shows a marked difference in how we approach real-world IFR flying. When I take off, it's highly unlikely that I will have an approach loaded. My flight plan will contain my cleared route, and end at my destination airport (or clearance limit). As I get closer to my destination, ATC will either ask which approach I want, or advise me which approach to expect. At that point I load that approach but don't activate it. At a later point, ATC will either clear me to the IAF and clear me for the approach, or they'll start vectoring me to final. At that point, and only at that point, do I activate the approach. In between being told what to expect and actually getting the clearance for the approach I may get a hold, or I may get vectored all over the place.

If I were VFR, you're "You'll get there eventually" would work ok. But I think Garmin's flight planning logic reflects a clear understanding that an instrument approach is something you negotiate (unless you get a cruise clearance) and that it shouldn't be part of your flight plan sequence without deliberate action on the part of the pilot, whether that action is activating the approach or otherwise getting the procedure to be an active leg of the flight plan.

Edit: This may all come down to a difference in the method we use to ensure we're on the approach section of the flight plan. I feel that the method I described above is the "best" way, and that's how I teach it, but other ways do work as well.

 

[TMetzinger]

I was just experimenting with the 400 series simulator, and if the thing is correct, there is another way to get to the approach. I found that if there is no active flight plan and no direct-to course active, then loading a flight plan causes it to take me direct to the IAF I selected. So it appears that the only thing manual activation does is to make it skip over any flight plan waypoints that are not part of the approach. However I haven't experimented with VTF or procedure turns yet.

That's true, but would you really be flying around under IFR with no active plan or waypoint?

 

[dmccormack]

To me this shows a marked difference in how we approach real-world IFR flying. When I take off, it's highly unlikely that I will have an approach loaded. My flight plan will contain my cleared route, and end at my destination airport (or clearance limit). As I get closer to my destination, ATC will either ask which approach I want, or advise me which approach to expect. At that point I load that approach but don't activate it. At a later point, ATC will either clear me to the IAF and clear me for the approach, or they'll start vectoring me to final. At that point, and only at that point, do I activate the approach. In between being told what to expect and actually getting the clearance for the approach I may get a hold, or I may get vectored all over the place.

If I were VFR, you're "You'll get there eventually" would work ok. But I think Garmin's flight planning logic reflects a clear understanding that an instrument approach is something you negotiate (unless you get a cruise clearance) and that it shouldn't be part of your flight plan sequence without deliberate action on the part of the pilot, whether that action is activating the approach or otherwise getting the procedure to be an active leg of the flight plan.

I agree -- but is there any other way to fly "real world" IFR with a Garmin product...?

This is the only way I do it -- I can't see the point of any alternate.

 

[Ted]

My KLN94 works the same way as well. You can load the approach whenever you want, but you need to load it in. Makes sense, seeing as frequently if an instrument approach requires me to go off to the other side of the airport I'll attempt a visual first and then go do the approach, unless weather is bad enough that there's no question I need to do the approach.

 

[Palmpilot]

That's true, but would you really be flying around under IFR with no active plan or waypoint?

I can think of situations in which this could happen:

-The enroute portion of the flight might have been flown using ground based navaids.

-Pretty much all IFR clearances between the Montery, CA area and Palo Alto are radar vectors followed by direct to a VOR.

-Some flights are so short that the entire clearance is radar vectors.

-A VFR aircraft could request a pop up clearance for an approach.

On the other hand, direct to destination is so easy to put in that it would probably be rare not to have at least that entered. I'm just saying that it could happen, so it doesn't hurt to know what to expect in that situation.

 

[jesse]

I've seen pilots that become too overly dependent on their technology and I've seen pilots that can't hardly use the technology they do have because they fear becoming overly dependent.

I am personally convinced that the Garmin 430 is the most reliable piece of equipment in the airplane I fly. I've seen nearly everything else fail during my years of renting (including the Hobbs). I've never seen a 430 fail.

In the end, I can fly with or without the 430. In general I don't want to focus on any one thing too long flying. That means I'm most likely to use whatever tool requires the least of my attention so that I can better watch the big picture. If something fails I'll know and I'll devote more attention to it. Flying an ADF or a VOR is not freaking hard. It just requires more human cpu..which I only have so much of.

I flew a VOR approach not too long ago into an airport with a 600 foot ceiling at night. I had the CDI tuned to the VOR and the approach loaded into the 430 as well for a second reference. I never really play "chase the needle" too much and prefer to just release some CPU and keep my brain on the overall situation. Interestingly enough the altimeter stuck which didn't bother me at all because I had a lot of CPU available to think about it. Don't panic and don't focus too hard on one thing and you'll be fine.

 

[olasek]

Edit: This may all come down to a difference in the method we use to ensure we're on the approach section of the flight plan. I feel that the method I described above is the "best" way, and that's how I teach it, but other ways do work as well.

Tim, of course, my above arguments are not to be confused with real world IFR procedures. It was only to dispel any misunderstanding about how Garmin units operate. By the way, it is not totally unlikely that when you take off you will end up with and IAF that you planned from the start. During the Cirrus open house at Hayward airport that I mentioned above and where Max was guest speaker - that was the first question he posed to his audience - to explain the difference between approach activation and loading and then he asked whether activation was necessary. There were a few CFIIs in the audience who had no clue that activation was not necessary, so it does come as a shock to some who hear about it for the first time.

Rod Machado in his IFR handbook states clearly how CDI sensitivity changes (page 13-4): When flying GPS approaches , CDI sensitivity will automatically change based on the airplane's position from the airport and its position along the approach course.

 

[airdale]

... direct to destination is so easy to put in that it would probably be rare not to have at least that entered ...

Just a comment on this:

When I first started flying these boxes, I saw no reason to load a two-point airport->airport flight plan when I could just push the Direct-To button. But I learned ...

If you just use Direct-To and then you get a reroute, you are in the doo-doo. Before you can add a waypoint, you have to create that two-point flight plan. My lesson came one time when I was cleared direct but trying to stay low because of headwinds. Center was very nice and overlooked the fact that I was below their radar coverage, but the TRACON controller next in line would not take me unless I either climbed or got on an airway. Airway was my choice, I got cleared to an intersection to join, and hence needed to quickly add that intersection to my nonexistent flight plan. Arggh.

So now my use of Direct-To is limited to VFR flights where there is no chance I'll need a pop-up. The two-point flight plan is hardly more effort anyway since the departure point defaults to your current location.

 

[gismo]

Just a comment on this:

When I first started flying these boxes, I saw no reason to load a two-point airport->airport flight plan when I could just push the Direct-To button. But I learned ...

If you just use Direct-To and then you get a reroute, you are in the doo-doo. Before you can add a waypoint, you have to create that two-point flight plan. My lesson came one time when I was cleared direct but trying to stay low because of headwinds. Center was very nice and overlooked the fact that I was below their radar coverage, but the TRACON controller next in line would not take me unless I either climbed or got on an airway. Airway was my choice, I got cleared to an intersection to join, and hence needed to quickly add that intersection to my nonexistent flight plan. Arggh.

So now my use of Direct-To is limited to VFR flights where there is no chance I'll need a pop-up. The two-point flight plan is hardly more effort anyway since the departure point defaults to your current location.

Doesn't setting up a departure to destination FP also provide an easy way to set up an approach for your departure airport in case you need to come back in for some reason?

 

[airdale]

Doesn't setting up a departure to destination FP also provide an easy way to set up an approach for your departure airport in case you need to come back in for some reason?

I dunno. I have never done that, though it's probably worth investigating.

I did try with the G430 simulator just now and I don't see an easy way to set up an approach to my FPL departure airport. The best I could come up with was to highlight the departure airport in the FPL, then do a direct-to, then select an approach and a transition. But I certainly wouldn't want to do that before departing as then I don't have the outbound course any more. With a regular FPL active the box will only let me select approaches to the destination airport. At least as far as I can figure out. Maybe I am missing something.

A real-world way to do this would be, in an emergency, use NRST, Direct-Enter-Enter, then select an approach and a transition. But, jeez, that would be a prohibitive amount of work if the emergency was at all serious. Maybe for a rough engine or some ice, but probably not a winning strategy with a fire or a dead engine. That might be the day I'd try to fly to the airport using the map screen!

Another, probably better, technique I have heard recommended is to set up a return approach to the departure airport just using the conventional radios. I remember once setting up an ILS return on a potentially icy day when I was feeling paranoid, but I think that's the only time I have done it. Probably I should be more paranoid.

 

[bbchien]

Doesn't setting up a departure to destination FP also provide an easy way to set up an approach for your departure airport in case you need to come back in for some reason?

Yes it does, as you can just reverse the FP.

But as a practical matter in Chi or NewYawk airspace, the reroutes are so common that once I get, Runway Hdg, SAX V39 and I get SAX into both the GPS and the VOR (115.7 and ID'd) I get turn direct SWEET ELIOT FJC (Allentown 117.5) there's almost NEVER a point to putting in much more than the next waypoint.

In C90 and N90 space I have never had to fly the full route clearance, as they are always trying to get rid of us as fast as we can.

In a multi, you identify and feather the dead engine, NRST, D-->D-->Enter and then talk. Takes eight seconds, max.

 

[maddog52]

I am surprised at the number of pilots I've flown with as a safety pilot or just talked with whose normal mode of operation with a GPS is to just fly the little airplane along the magenta line. This for enroute and holds especially, but even on approaches.

I have always considered this to be sloppy flying at best and dangerous at worst. The accuracy depends on screen magnification, you lose over time the ability to fly using the needles, and you lose over time the ability to maintain situational awareness if the little map is not available.

quote]

I've seen the the same thing. There is a term for it:

Main Entry: 1glasshole
Pronunciation: \ˈglas-,hōl\
Function: noun
Usage: often attributive
1 : a phenomenon found in “glass cockpits” where the high tech instruments have such a strong attraction that the pilots attention is sucked into them causing fixation and lack of situational awareness. Usually accompanied by complacency and over reliance on automation
2 : a pilot who has become so used to relying on high tech instrumentation that his basic instrument and navigation skills have eroded to a state of non-proficiency. Often found amid aircraft wreckage following failure of the high tech equipment


Beware the glasshole, don't become a glasshole.

 

[tonycondon]

i thought glassholes were jerks who flew fiberglass gliders