GTN 650/750 approach

[Jim Peace]

19 minutes ago, Jim Peace said:

So if I am flying a STAR that hooks directly up to an RNAV approach do I have to activate anything and if so when?...if I activate it too early will it take me off of the STAR and directly to the IAF ir IF?.....why should I have these questions years after ownership...?

Not exactly,,,

I will continue to do what I have been doing....push all the buttons on all the pages until I see something I like...

I do not know anything about Dynon or Avidyne...are they this complicated?

[midlifeflyer]

30 minutes ago, Ragsf15e said:

When you load the full approach you are loading something that you don’t think will happen but could happen.  You might guess wrong. 

I see that differently. Arguably semantics, but I don't think so. When you load the full approach you are giving yourself options for whatever happens. You can't be "wrong" unless you are approaching from the northeast and, on a T configured approach, select the logical easterly IAF for your direction of travel, but for some reason ATC wants you to cross over and come in form the other side. 

[Ragsf15e]

Just now, midlifeflyer said:

I see that differently. Arguably semantics, but I don't think so. When you load the full approach you are giving yourself options for whatever happens. You can't be "wrong" unless you are approaching from the northeast and, on a T configured approach, select the logical easterly IAF for your direction of travel, but for some reason ATC wants you to cross over and come in form the other side. 

Yes, that’s what I meant, but I think that way even if I’m planning vtf.  That’s the “guess” part.  I’m planning vtf, but I’m loading more than that just in case I get sent somewhere else.  There’s lots of approaches with multiple iafs or IFs that could happen even though the pilot planned vtf.  

[midlifeflyer]

59 minutes ago, Jim Peace said:

Not exactly,,,

I will continue to do what I have been doing....push all the buttons on all the pages until I see something I like...

I do not know anything about Dynon or Avidyne...are they this complicated?

Depends on what you think is complicated. None of the systems simply assumes you want to fly an IAP or where you want to join it just because you load it. They're good but they don't  read your mind. You have to tell them somehow. Making a leg or waypoint active doesn't strike me as overly complicated,

[kortopates]

VTF versus the full approach from an IAF or IF:

You can't go wrong ever loading the full approach and I always used to teach always to load the full approach and then activate the leg you are being vectored onto - without exception. This is still the only way to fly a NPA IMO.

But VTF works just fine on any PA where you know you are being vectored on to final. Why? We almost never care about intermediate fixes on a PA when we know we'll be instructed to intercept final approach coarse and told to maintain a final altitude till established - in which case we don't care about those intermediate waypoints and their altitudes - we're following the GS for vertical guidance. There are of course exceptions, such as some of the long ILS with lot's of step downs, such as coming into LAX with mandatory altitudes not associated with the glideslope. So if not familiar, stick with the always safe and sure approach of loading the full approach with the nearest IF transition, then re-activate the correct leg for where you are being vectored onto the approach.

But the GTN's even made VTF more powerful by adding the waypoints on final outside of the FAF. Although with VTF loaded, when you activate the approach, it will still show the coarse guidance only to FAF, the waypoints outside of the FAF on the final are still loaded right behind the FAF. So if the controller at the last minute clears you direct to one of these waypoint or tell you to intercept one of these legs then you need only to bring up the flight plan page by touching the CDI on GTN map page and then touch the waypoint to either go direct or to activate that leg in front of that waypoint. You no longer need to re-load the full approach to get those waypoints back! 

Bruce's charts didn't discuss the finer points of VTF with the GTN's so I suggest if you aren't aware of this to study it more on the GTN simulator because VTF just got a lot more powerful on the GTN's and VTF's is what teach for flying any PA when you know you are being vectored onto final. And with the GTN it still works out fine if you get a last second surprise with an earlier waypoint or leg on final before the FAF. 

Edited January 17, 2021 by kortopates

[donkaye]

2 hours ago, Ragsf15e said:

Yeah, fair enough.  When you load the full approach you are loading something that you don’t think will happen but could happen.  You might guess wrong.  I would be pretty hesitant not to load or activate anything just because you might get something unexpected and then have to reload.  Here’s why... when I load the approach during cruise after getting atis, I can go through it slowly and carefully check the waypoints, decision altitude, etc.  On an ILS you also need to double check the loc frequency it populated.  I typically activate VTF as soon as I start getting vectors so I can get dme to the faf and double check the course setting and freq.

You are 100% right that there may be a reload in there if the plan changes, but I’d rather not ensure that I have to load it every time right before intercepting final.  There are many ways that work depending on our preferences.

With the GTNs all waypoint are included with VTF.  Not so with the GNSs.

[midlifeflyer]

10 minutes ago, donkaye said:

With the GTNs all waypoint are included with VTF.  Not so with the GNSs

All the waypoints along the FAC.

[donkaye]

2 hours ago, Jim Peace said:

So if I am flying a STAR that hooks directly up to an RNAV approach do I have to activate anything and if so when?...if I activate it too early will it take me off of the STAR and directly to the IAF ir IF?.....why should I have these questions years after ownership...?

As GA plots we almost never get STARS.  I can only think of 1 arrival STAR I sometimes get when going into KSMO.  Assuming you do get one, though. the STAR is just part of the enroute box and behaves the same.  Fly it all and transition to an approach automatically, or proceed to a waypoint or leg on the approach and that actives the approach.

Maybe I'm missing something, but I've found the Garmin way pretty logical.  If you're still having problems understanding it, get with an instructor who is familiar with the Garmin way and they'll get you sorted out pretty quickly.

[Ragsf15e]

32 minutes ago, donkaye said:

With the GTNs all waypoint are included with VTF.  Not so with the GNSs.

Interesting.  What does it do if there are multiple IAFs with different routes to the faf?  I.e. an rnav T shaped approach.

[donkaye]

8 minutes ago, Ragsf15e said:

Interesting.  What does it do if there are multiple IAFs with different routes to the faf?  I.e. an rnav T shaped approach.

When you load the approach you are give the opportunity to choose the Transition.  With the  GTN it's easy to change on the fly.

[ArtVandelay]

Interesting.  What does it do if there are multiple IAFs with different routes to the faf?  I.e. an rnav T shaped approach.

It doesn’t include all the way points, just the appropriate way points.

[midlifeflyer]

4 minutes ago, ArtVandelay said:

It doesn’t include all the way points, just the appropriate way points.

"Appropriate" is a judgment. It includes all procedure waypoints along the extended final approach course. 

[midlifeflyer]

20 minutes ago, Ragsf15e said:

Interesting.  What does it do if there are multiple IAFs with different routes to the faf?  I.e. an rnav T shaped approach.

It doesn't include them. That's why many think it's better to choose an appropriate one to begin with. 
 

[PT20J]

Garmin has created a a perennial source of confusion with the term ACTIVATE. Activating an approach simply means: Fly present position direct to the first waypoint (IAF) on the currently loaded approach procedure and resume auto-sequencing. This is almost never what you want to do. But there is a general misconception that somehow you must always “activate” an approach to fly it, and so I’ve seen some use the Activate function when they really don’t need to. In reality, you can make any waypoint or leg (outside of the FAF) of the loaded approach procedure active and the GPS will auto-sequence through the approach. 

Skip
 

 

 

[Vance Harral]

A lot of the discussion above centers around how to avoid reloading the approach, when you get a late clearance change you weren't expecting.  The commonly-discussed case is when you thought you were getting vectors to final, then you get cleared to an IAF or IF instead.  Hence the "Never load VTF" strategy to avoid that particular case.

I have a contrarian position about this.  I teach students to practice reloading approaches to select a different transition, until they can do it quickly and correctly with little anxiety or stress.  Then the guidance on loading approaches becomes simply, "Load your best guess at a transition/VTF, change as needed".

Using myself and my own airplane as an example, I don't consider it some kind of workload crisis if I've loaded one transition (VTF or otherwise), and then get cleared to a fix not in my flight plan.  The HOME -> PROC -> Approach -> Transition -> Activate sequence on a GTN navigator is pretty ingrained, so just a few seconds and no big deal to change the plan.  If I'm being cleared to an IF rather than an IAF, then the extra steps are HOME -> Flight Plan -> select fix -> Activate Leg.  It's a little more involved on an "etch-a-sketch" GNS navigator, but I teach in some airplanes with those, and I still don't think it's too bad: reload with PROC -> big knob to Select Approach -> Enter -> Enter -> Big knob to select transition -> Enter -> Enter.  If being cleared to an IF instead of an IAF, add FPL -> big knob to select fix -> Direct -> Enter -> Enter.

My main problem with the "Always load this, never load that" strategy, is it primes the student to think switching to a different transition is somehow "scary" and/or an unfair request by ATC.  That doesn't bode well for fairly common situations that require deft button-ology even without ever loading VTF.  e.g. training/proficiency flights with multiple approaches in compressed time and space, and/or ATC reroutes to a different IAF/IF late in the sequence for legitimate operational reasons.

I have a lot less instruction given than Mark, Gary Reeves, etc.  You should weight their opinions more than mine.  But I think it's fair to say that "Never load VTF" doesn't guarantee you'll never have to reload an approach late in the game.  So just like you're expected to be able to hand-fly an approach without an autopilot, fly partial panel if an instrument fails, etc; so should you also be reasonably proficient at reloading approaches to select a different transition.  As Don says above, it's just not that hard to change on-the-fly (literally in this case ).

[gsxrpilot]

I'll second what @Vance Harral is saying. I was flying safety pilot for him on some practice approaches, Saturday morning. Over the course of three approaches, I lost track of how many times he switched up the sequence on the GTN650. But it didn't seem to matter what a very busy Denver Approach controller threw at him, he just updated the route on the GTN and moved on. I'm an Avidyne guy and so it all looked very complicated to me, but it was child's play for Vance.

Here's some partial panel action...

[HXG]

Not sure if everyone is aware, but no need to hit HOME to get the Flight Plan on the GTN. Instead, tap  the active leg line ABOVE the CDI (circled in red below) on the map or default nav page to open the flight plan. You can also load and activate an approach from the flight plan page if you want although hitting HOME then PROC is pretty quick.

Personally, I like using minimum steps cycling between Map and Default Nav page and Back and tapping the CDI on the GTN for the flight plan during flight. I also load my expected approach and use activate legs, Direct to IAP Fix or AVTF depending on the situation. If you’re activating the IAP within 2-3 miles of the FAF, you’re probably a little behind the airplane. 

 

Edited January 18, 2021 by HXG
Tap LINE ABOVE CDI to open Flight Plan

[Vance Harral]

41 minutes ago, gsxrpilot said:

I was flying safety pilot for him on some practice approaches, Saturday morning.

I think Paul has his pictures confused. That's some old, gray-bearded dude in the left seat.  Couldn't possibly be me.

[Vance Harral]

13 minutes ago, HXG said:

no need to hit HOME to get the Flight Plan on the GTN. Instead, tap the CDI (circled in red below) on the map or default nav page to open the flight plan

That is a great tip, thanks!

[donkaye]

2 hours ago, Vance Harral said:

 

Using myself and my own airplane as an example, I don't consider it some kind of workload crisis if I've loaded one transition (VTF or otherwise), and then get cleared to a fix not in my flight plan.  The HOME -> PROC -> Approach -> Transition -> Activate sequence on a GTN navigator is pretty ingrained, so just a few seconds and no big deal to change the plan.  If I'm being cleared to an IF rather than an IAF, then the extra steps are HOME -> Flight Plan -> select fix -> Activate Leg.  It's a little more involved on an "etch-a-sketch" GNS navigator, but I teach in some airplanes with those, and I still don't think it's too bad: reload with PROC -> big knob to Select Approach -> Enter -> Enter -> Big knob to select transition -> Enter -> Enter.  If being cleared to an IF instead of an IAF, add FPL -> big knob to select fix -> Direct -> Enter -> Enter.

The new GTN Xi software update makes things even easier.  Garmin brought back a shortcut bar like the knob on the GNS that cycled from NAV- Waypoint-Aux-NRST, so from any page you can quickly take a shortcut to another page.  So, for example, say you're on the MAP page and want to load an approach.  Instead of a number of Taps to get to the Procedures Page, you'd just twist the knob a couple of turns and you're on the Procedures Page.  You can set up a number of shortcuts that best suit your flying needs.

[Ibra]

15 hours ago, midlifeflyer said:

With a GNS you are literally reloading the approach from scratch during the highest workload period. Maybe a little easier wit a GTN or G1000. But because of that many teach neither loading or activating it - ever.  "Activate leg" is the preferred alternative

Fly Direct-to WPT or Activate Leg should work in all boxes in the same way: simple FPL sequencing (except in hold/missed/OBS mode where one suspends) 

In theory, no point VTF or load/activate (apart from checking distances/tracks against plates), one could just fly Direct-to IF/IAF or intercept an (IAF,FAF) active leg when requested by ATC, the rest would just flow naturally... 

PS: starting all from scratch with 3 fresh clicks is way easier than understanding what the hell went wrong in my last 20 clicks, also quick "3 clicks in 10s" is a usefull skill to have with busy ATC: things raraly go as planned even if your FPL page was properly setup before takeoff 

Edited January 18, 2021 by Ibra

[midlifeflyer]

11 hours ago, Vance Harral said:

  I teach students to practice reloading approaches to select a different transition, until they can do it quickly and correctly with little anxiety or stress. 

So do I. I even teach them to practice loading a different approach. But not so they can fix  something they could have done more efficiently to begin with. 

[midlifeflyer]

1 hour ago, Ibra said:

Fly Direct-to WPT or Activate Leg should work in all boxes in the same way:

It does. "Reloading from scratch" is only needed if you have deleted them or never loaded them to begin with. Exactly the point. On a T approach, coming in from the NoPT sector, I will ask for and probably get direct to the IF. I'm naturally lazy, so far more efficient for me to load the logical T on my side and go direct to the IF when instructed than to change the transition if due to traffic, ATC needs to send me to the T. Yes, of course ATC can send me to the "wrong" T so ultimately it's only a 90/10% guess.

Yeah, I know I tend to rant about this. In addition to being lazy, I also fly and teach in different aircraft with different avionics packages, so a consistent working methodology has value. I find it also helps transitioning pilots by keeping familiar things familiar and focusing on the truly different. 

it's not only VTF which does that. I know people who "clean up" the flight plan by deleting waypoints before the one they are going to. But that's more of a STAR thing than an IAP thing.
 

BTW, I do not use my preference to violate my First Commandment of instructing - "Thou shalt not change a technique which works s just because you like another better."  Yes, I may well set up a scenario where I think it would be a better technique to load an IAF rather than VTF, but if they hand it well I won't try to force a change.

 

[toto]

9 hours ago, donkaye said:

The new GTN Xi software update makes things even easier.

This is very interesting. I have held off doing the Xi switch because the avionics shop said it's basically higher resolution with the same functionality. I hadn't realized that there were significant changes in the interface or workflow. 

[midlifeflyer]

12 hours ago, PT20J said:

But there is a general misconception that somehow you must always “activate” an approach to fly it,

Agreed. It's actually worse than that since you do have to "activate an approach" in order to fly it (I have a friend this happened to recently)  but you never need to select "Activate Approach." Fortunately, there are many out there preaching that you never have to use that "Activate Approach" menu item.