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Speedbird1 View Drop Down
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    Posted: 02 Jul 2020 at 10:40am
I've watched many videos about this but it appears something isn't right.

I setup a FPL from KERV to T82 and activate it.  Now I click PROC and add the RNAV 32 (LPV) approach and choose CIRIX as my transition.  As expected the active route is still direct from KERV to T82.  I then click on CIRIX and choose Direct to.  Now the magenta line is from my present position to CIRIX.  Still, all is good.  GPS->LPV is displayed in the top right.  I then click on the --/ Gap /-- above CIRIX and choose CLR.  Now the active leg is between CIRIX and T82 and my aircraft is 'lost' and has no heading to fly. 

Is this a bug?  I'm using the IFD sim and have not tried this in real life.  

TIA
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I believe this is intended IFD behavior and not a bug. When you clear the GAP and your active waypoint is the first waypoint immediately following the GAP, you are indicating to the IFD that you want a new course to the active waypoint by connecting in this case T82 and CIRIX. That newly created T82 CIRIX leg becomes the active leg in the IFD. The IFD simulator takes up a course to intercept the new active leg.

My question is this: what additional functionality were you hoping to gain by closing the GAP? 

If you were cleared direct CIRIX and either cleared for or expecting to be cleared for the RNAV 32 at T82, the IFD was giving full guidance to accomplish that clearance when you chose Direct to CIRIX in your above example. The only other IFD route modification that may need to be made is deciding whether to retain or clear the course reversal hold at CIRIX based on the clearance or inbound course to CIRIX.

We had a GAP related thread on this forum a few months ago that I encourage you to look over. 

My personal view is that unless I'm given a routing clearance between an waypoint prior to the GAP and a waypoint after the GAP in the IFD flight plan, I cannot think of another reason off hand where it would be desirable or increase IFD functionality if I were to clear the GAP. In fact, trying to clear a GAP in the heat of the moment very likely may cause more confusion, unintended consequences, and routing errors as your example points out if you don't fully understand how the IFD handles each type of GAP closure. Just my take.
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Good question.  

By clearing the GAP I was hoping to 'tidy up' the route.  Ideally I would like to insert the approach before T82; however, from all I understand that would mean building the flight plan differently at the start.  Issue here is that sometimes you just don't always get the approach you want or expect (based on TAFs) once in the air.  Things change.   

Once I insert the approach I figured you are telling the IFD that you want to fly to the airport using the procedure you inserted.  I guess my logic mind is not that of Avidyne's.
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Originally posted by Speedbird1 Speedbird1 wrote:

Now the active leg is between CIRIX and T82 and my aircraft is 'lost' and has no heading to fly.

You shouldn't have lost anything, when you closed the gap, you just connected T82 to CIRIX and essentially activated that leg.  You could have hit Direct To CIRIX again and been all set or intercept the leg between T82 and CIRIX as the flight plan now expects.  If you intercept the leg between T82 and CIRIX, it'll switch to GPS->LPV as you enter the teardrop course reversal.
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Originally posted by brou0040 brou0040 wrote:

Originally posted by Speedbird1 Speedbird1 wrote:

Now the active leg is between CIRIX and T82 and my aircraft is 'lost' and has no heading to fly.

You shouldn't have lost anything, when you closed the gap, you just connected T82 to CIRIX and essentially activated that leg.  You could have hit Direct To CIRIX again and been all set or intercept the leg between T82 and CIRIX as the flight plan now expects.  If you intercept the leg between T82 and CIRIX, it'll switch to GPS->LPV as you enter the teardrop course reversal.

I totally agree; keep in mind that that the reason the T82 to CIRIX leg was activated in this case was due to CIRIX already being the active IFD waypoint when you cleared the gap between T82 and CIRIX. Had CIRIX not been the active waypoint when you cleared the gap between T82 and CIRIX, then the active waypoint and course to the active waypoint (magenta line) would not have changed.

The general point of my question was this; if in this scenario, say I were to clear the gap between T82 and CIRIX only to have to re-select direct to CIRIX. I have have now spent additional time with my attention diverted to the IFD and used a minimum combination of five additional button pushes or screen touches all to get the IFD to do exactly what it was already set to do had I just left it alone. While everyone is certainly entitled to use whatever technique works for them, for me in this scenario, clearing the gap seems like a great way to potentially introduce confusion and routing errors for zero functional gain. 
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I agree with leaving the gap here, but I think it's fair to say that it is natural for people to want to clear it.  Since the OP had hit Direct to CIRIX, I think it's a valid thought to want to maintain direct to CIRIX after closing the gap, which is what would have happened had the gap not been there, he had been on that segment, and then went direct to CIRIX.

I think it is a logical request to have the IFD remember the "Direct To" when closing the gap since if the pilot really wanted to reactivate the leg to CIRIX, he still could have.  The issue is that once you close the gap, all the LSKs are filled with "Offset Route", "View", and "Delete Waypoint" so you can't just hit CIRIX and activate leg - since it is already active.  You have to activate the T82 leg, then activate the CIRIX leg to get the current IFD behavior back.

I guess for me, if nobody is using or expecting to activate the leg between the two points when closing a gap over retaining the direct to input, I think changing this feature may prevent further issues with understanding the gap functionality in the IFD.


Edited by brou0040 - 06 Jul 2020 at 10:43am
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Gary Reeves at pilotsafety.org has a good video with a discussion on the gap and how to program the IFD to avoid it in the first place.
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Originally posted by Speedbird1 Speedbird1 wrote:

I setup a FPL from KERV to T82 and activate it.  Now I click PROC and add the RNAV 32 (LPV) approach and choose CIRIX as my transition.  As expected the active route is still direct from KERV to T82.  I then click on CIRIX and choose Direct to.  Now the magenta line is from my present position to CIRIX.  Still, all is good.  GPS->LPV is displayed in the top right.  I then click on the --/ Gap /-- above CIRIX and choose CLR.  Now the active leg is between CIRIX and T82 and my aircraft is 'lost' and has no heading to fly. 

Is this a bug?  I'm using the IFD sim and have not tried this in real life.  

By clearing the GAP I was hoping to 'tidy up' the route.  Ideally I would like to insert the approach before T82; however, from all I understand that would mean building the flight plan differently at the start.  Issue here is that sometimes you just don't always get the approach you want or expect (based on TAFs) once in the air.  Things change.   

Once I insert the approach I figured you are telling the IFD that you want to fly to the airport using the procedure you inserted.  I guess my logic mind is not that of Avidyne's.


The IFD is behaving exactly as it should.  You’ve told the IFD to navigate to your destination airport.  Then you load the approach and now there is a gap between the destination airport and the approach because the IFD doesn’t know how you expect to get onto the approach.  AND the destination airport has been added after the approach just as you desire.

At some point, and the IFD doesn’t know when, you’ll need to activate the approach and proceed to the IAF.  In the meantime, it continues to navigate to the destination airport as you programmed it to do.  If the destination airport was removed before the approach, there would now be a gap between the previous waypoint and the IAF.  Now what if you should be navigating toward the destination airport AFTER the previous waypoint and before activating the approach?  Now you’re missing a fix to navigate to.  So, it makes sense to leave the destination airport and add it again after the approach.  Then you can activate the approach at any point that is appropriate without losing any flight plan waypoints.

Clearing or closing the Gap is not “tidying up”.  It isn’t simply removing the words “Gap in route”, it is telling the IFD to add a leg to the route.  That certainly is not “tidying up”.  Look at the LSK at bottom left after activating the approach, but before you clear the Gap.  It is telling you that T28 and CIRIX will be connected by a leg.  Since CIRIX is the active waypoint and you added a leg to it, I think it is logical that the leg between T28 and CIRIX becomes active.  After all, why would you add a leg to your active waypoint if you didn't intend to fly it?

The Gap represents meaningful information concerning your programmed route.  Do not clear it unless you intend to change your programmed route.  A lot of folks don’t like seeing, “Gap in route”, and think they need to get rid of it.  Nonsense.  It is just information and there is nothing wrong with it being there. 

Here’s link to Gary Reeves video:
https://www.youtube.com/watch?v=vmoq281_nbI



Edited by Bob H - 07 Jul 2020 at 1:12am
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Originally posted by Bob H Bob H wrote:

Originally posted by Speedbird1 Speedbird1 wrote:

I setup a FPL from KERV to T82 and activate it.  Now I click PROC and add the RNAV 32 (LPV) approach and choose CIRIX as my transition.  As expected the active route is still direct from KERV to T82.  I then click on CIRIX and choose Direct to.  Now the magenta line is from my present position to CIRIX.  Still, all is good.  GPS->LPV is displayed in the top right.  I then click on the --/ Gap /-- above CIRIX and choose CLR.  Now the active leg is between CIRIX and T82 and my aircraft is 'lost' and has no heading to fly. 

Is this a bug?  I'm using the IFD sim and have not tried this in real life.  

By clearing the GAP I was hoping to 'tidy up' the route.  Ideally I would like to insert the approach before T82; however, from all I understand that would mean building the flight plan differently at the start.  Issue here is that sometimes you just don't always get the approach you want or expect (based on TAFs) once in the air.  Things change.   

Once I insert the approach I figured you are telling the IFD that you want to fly to the airport using the procedure you inserted.  I guess my logic mind is not that of Avidyne's.


The IFD is behaving exactly as it should.  You’ve told the IFD to navigate to your destination airport.  Then you load the approach and now there is a gap between the destination airport and the approach because the IFD doesn’t know how you expect to get onto the approach.  AND the destination airport has been added after the approach just as you desire.

At some point, and the IFD doesn’t know when, you’ll need to activate the approach and proceed to the IAF.  In the meantime, it continues to navigate to the destination airport as you programmed it to do.  If the destination airport was removed before the approach, there would now be a gap between the previous waypoint and the IAF.  Now what if you should be navigating toward the destination airport AFTER the previous waypoint and before activating the approach?  Now you’re missing a fix to navigate to.  So, it makes sense to leave the destination airport and add it again after the approach.  Then you can activate the approach at any point that is appropriate without losing any flight plan waypoints.

Clearing or closing the Gap is not “tidying up”.  It isn’t simply removing the words “Gap in route”, it is telling the IFD to add a leg to the route.  That certainly is not “tidying up”.  Look at the LSK at bottom left after activating the approach, but before you clear the Gap.  It is telling you that T28 and CIRIX will be connected by a leg.  Since CIRIX is the active waypoint and you added a leg to it, I think it is logical that the leg between T28 and CIRIX becomes active.  After all, why would you add a leg to your active waypoint if you didn't intend to fly it?

The Gap represents meaningful information concerning your programmed route.  Do not clear it unless you intend to change your programmed route.  A lot of folks don’t like seeing, “Gap in route”, and think they need to get rid of it.  Nonsense.  It is just information and there is nothing wrong with it being there. 

Here’s link to Gary Reeves video:
https://www.youtube.com/watch?v=vmoq281_nbI


I fully agree with Bob H on this.

I understand there may be a natural tendency, especially for a pilot that is somewhat new to FMS navigation, to want to close route discontinuities (gaps) in the flight plan. My general “leave the gap alone” technique perspective comes from decades of training on and using Boeing and Airbus FMS navigation in the airline environment prior to having an IFD540. Route discontinuities in that environment essentially only get closed with cleared routing via FMS waypoints on both sides of the route discontinuity. In the case of radar vectors or direct-to IAF routing from the arrival to approach, we perform equivalent activate leg or direct-to operations with the appropriate waypoint on the approach side of the route discontinuity as those clearances are issued to sequence the active waypoint and set the FMS up to follow appropriate post gap routing.

The Avidyne IFDs FMS navigation ideology is quite similar to the Thales, Smith, and Honeywell FMCs found in Boeing and Airbus aircraft. So much so that I have found many of those time-tested FMS practices used at the airline also work quite well as techniques with Avidyne IFD navigation in my GA flying.

I would argue that needlessly clearing gaps in areas where additional ATC routing instructions are required to transition between phases of flight generally:

·         increases workload and time spent focused on the IFD with no functional gain

·         increases the chance of unintended consequences and routing errors

·         increases map clutter with a displayed leg that isn’t intended to be flown

·         does not prevent from having to perform the same future routing modifications that occur where the gap was located.

Lastly, if your IFD routing exactly matches the cleared routing for the current phase of flight, a gap may increase situational awareness of approaching a clearance limit as the gap is displayed pictorially on the map, in flight plan, and an FMS advisory “Gap in Route Ahead” message is displayed within three minutes of the discontinuity.

Once again, just my take. 
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I don't think you actually read what I wrote or maybe you assume that I didn't activate the approach.  You are correct that I loaded the approach and activated it (by choosing direct to the IAF).  Once I've done that I *then* deleted the gap.  
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Originally posted by Speedbird1 Speedbird1 wrote:

I don't think you actually read what I wrote or maybe you assume that I didn't activate the approach.  You are correct that I loaded the approach and activated it (by choosing direct to the IAF).  Once I've done that I *then* deleted the gap.
Yes, I'm aware that you deleted the gap after activating the approach.  Everything I wrote is consistent with that.  I talked about the active waypoint being CIRIX when you closed the gap which added a leg from T28 to CIRIX.  CIRIX is the active waypoint only AFTER the approach is activated.  The bottom line is that after stepping over the gap by activating the approach or going direct to the IAF, you are going back and adding a new leg to the active waypoint.  Why?  What is the point?  It is not an error to have "Gap in route" in the waypoint list.  It is useful information for the pilot.  That is the way an FMS works.  Is it not logical that when you are navigating to a waypoint and then add a new leg to that waypoint, that the IFD interprets that as wanting to fly that leg?  Why add a leg to your active waypoint that you have no intention of flying?  Just step over the gap and keep going.  Perhaps the example being sighted is too simple.  It is only two airports with no intervening waypoints.  Please help me understand what the problem is that you are trying to solve.  I don't see one.
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Originally posted by Speedbird1 Speedbird1 wrote:

I don't think you actually read what I wrote or maybe you assume that I didn't activate the approach.  You are correct that I loaded the approach and activated it (by choosing direct to the IAF).  Once I've done that I *then* deleted the gap.  


 
I believe I understood what you wrote from your first post. After you "activated" the approach with a direct to CIRIX the IFD was set to go direct to CIRIX and continue with routing after the gap. Nothing else was required if that was your intended routing. As far as the IFD was concerned, the gap is behind it in the flight plan. Trying to close the gap at this point is essentially trying to edit the flight plan behind you; except, your edit happened to include the active waypoint which caused the unintended consequence.

If the intended routing was via T82 then CIRIX, then closing the gap before crossing T82 would have been desirable and there would not have been any unintended consequences. The approach would then automatically activate upon crossing CIRIX.

I'm not sure why there is extra emphasis on having activated the approach or not in this scenario. Approach activation is pretty seamless and automatic with the IFD as opposed to other navigators on the market. Gaps in the IFD; however, may be found between other phases of flight, not just before approaches. There a some gaps in the IFD that cannot be deleted.
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Originally posted by Speedbird1 Speedbird1 wrote:

...By clearing the GAP I was hoping to 'tidy up' the route....



The way you do that is, after loading the approach, select the "activate approach" LSK.

Doing that will eliminate the gap, and change your routing to "direct to" CIRIX.  And you will be all "tidy'd up."  All the charted approach segments from CIRIX to the missed approach point will be in the FMS flight plan.

There is a drawback to doing this, if you choose to do so before hearing the words "cleared for the approach."  If you have activated an approach before being cleared, and the clearance you receive is for a different approach, you will have to delete the approach in the FMS and load a new one.  Which will cause your "direct to" leg to CIRIX to disappear.  This scenario will keep you pretty busy unless you practice it often enough.

It's easier just to load the approach and leave the GAP alone.  You're heading towards the airport (or other waypoint in your clearance), and you should really not change that until you get an updated clearance.

So load the approach you expect, but don't delete the GAP.  After being cleared for that very approach, either hit the "activate approach" LSK or proceed "direct to" CIRIX and forget the GAP.  But if you've been cleared for a different approach, just go to the FPL entry for T82, delete the loaded approach from the FPL entry for T82, and select the approach that you have been cleared for.  It's faster that way, so it's what I think is preferable when a controller surprises me with a different approach.  Of course, I can always reject any clearance if I'm being rushed, but I prefer to prepare in advance so I'm not.
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Originally posted by Catani Catani wrote:

Originally posted by Speedbird1 Speedbird1 wrote:

...By clearing the GAP I was hoping to 'tidy up' the route....
The way you do that is, after loading the approach, select the "activate approach" LSK.

Doing that will eliminate the gap, and change your routing to "direct to" CIRIX.  And you will be all "tidy'd up."  All the charted approach segments from CIRIX to the missed approach point will be in the FMS flight plan.
Agreed, but minor nit.  For clarity, activating the approach does not eliminate the gap, it just puts it in the rearview mirror, so it is of no consequence.  Eliminating the gap means connecting the before waypoint with the after waypoint with a leg.
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We are going to continue to see these questions as new people continue to buy IFDs.  Sure, you can explain the purpose, that is not my point.  My point is that this isn't a new question and will be asked many times again.  If the IFD modified the route but maintained the current navigation, this issue could be reduced.  There is nothing that is forcing the IFD to switch from Direct to CIRIX to activating the new leg.  It could connect the waypoints and retain the current navigation of Direct to CIRIX.  I still haven't heard a case for why that is a bad idea.
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Originally posted by brou0040 brou0040 wrote:

We are going to continue to see these questions as new people continue to buy IFDs.  Sure, you can explain the purpose, that is not my point.  My point is that this isn't a new question and will be asked many times again.  If the IFD modified the route but maintained the current navigation, this issue could be reduced.  There is nothing that is forcing the IFD to switch from Direct to CIRIX to activating the new leg.  It could connect the waypoints and retain the current navigation of Direct to CIRIX.  I still haven't heard a case for why that is a bad idea.
Of course.  We see the same questions all the time about multiple aspects of the IFD as folks install and learn about it.  That is the point of this forum – to help each other obtain and maintain proficiency.

Reasons?
1. The IFD FMS gap architecture is consistent with the heavy iron FMS systems.  That allows for better transitioning to those systems and allows Avidyne to better sell into those markets.
2. Changing the gap behavior of the IFD will mask user misunderstandings about the gap, its purpose, and how it should be used.
3. Changing the gap behavior of the IFD will facilitate the pilot undertaking useless programming for a leg that is behind them when the busiest time of the flight is just beginning.
4. The current gap architecture is the most logical.  It makes the most sense that if I am going to program a leg, I want to use that leg.
5. Changing this gap behavior will not stop questions about the gap for understanding its purpose and how best to treat it.
6. I may choose to close the gap because I actually want to intercept that leg (yes, even after the approach has been activated.)  I should be able to do that without a lot of extra button pushes simply because the architecture was changed so someone else can make unnecessary flight plan changes that has no effect on their flight path.  In other words, the change will facilitate those who don’t need to make changes and hinder those that do – all so someone doesn’t need to ask questions to properly learn about the IFD.

Maybe a better question is: Why should it connect the waypoints and retain the current navigation of Direct to CIRIX.  I still haven't heard a case for why that is a good idea.
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Originally posted by Bob H Bob H wrote:

Originally posted by Catani Catani wrote:

Originally posted by Speedbird1 Speedbird1 wrote:

...By clearing the GAP I was hoping to 'tidy up' the route....
The way you do that is, after loading the approach, select the "activate approach" LSK.

Doing that will eliminate the gap, and change your routing to "direct to" CIRIX.  And you will be all "tidy'd up."  All the charted approach segments from CIRIX to the missed approach point will be in the FMS flight plan.
Agreed, but minor nit.  For clarity, activating the approach does not eliminate the gap, it just puts it in the rearview mirror, so it is of no consequence.  Eliminating the gap means connecting the before waypoint with the after waypoint with a leg.

In my experience, both of you are correct depending on the circumstances. The Activate Approach LSK is an interesting command that is only available if the active waypoint is the waypoint preceding a gap before an approach. As far as I can tell it behaves three different ways depending on the situation: 
  1. If the active waypoint is the airport the non-VTF approach is based on, the Activate Approach LSK will perform a direct-to the IAF waypoint and the gap will be retained. 

  2. If the active waypoint is anything other than the airport the non-VTF approach is based on, the Activate Approach LSK will connect the active waypoint and the IAF waypoint, thus eliminating the gap.

  3. If the active waypoint any waypoint preceding the gap before a VTF approach, the Activate Approach LSK will perform and activate leg to the FAF waypoint and the VTF gap will be retained (IFD may or may not retain a published dog-leg inbound to the FAF).
As I understand the original scenario, had Speedbird1 used the Activate Approach LSK while the active waypoint was T82, the result would have been identical to the original described direct-to CIRIX result because the active waypoint was T82 (the airport the approach was based on). 

While not a technique I'm a personal fan of: in this scenario the cleanest way I can think of to "tidy-up" the route would have been to clear the gap either before performing the direct-to CIRIX or after crossing CIRIX. 


Edited by dmtidler - 08 Jul 2020 at 12:35pm
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Originally posted by dmtidler dmtidler wrote:

In my experience, both of you are correct depending on the circumstances. The "Activate Approach" LSK is an interesting command that is only available if the active waypoint is the waypoint preceding a gap before an approach. As far as I can tell it behaves three different ways depending on the situation: 
  1. If the active waypoint is the airport the non-VTF approach is based on, the Activate Approach LSK will perform a direct-to the IAF waypoint and the gap will be retained. 

  2. If the active waypoint is anything other than the airport the non-VTF approach is based on, the Activate Approach LSK will connect the active waypoint and the IAF waypoint, thus eliminating the gap.

  3. If the active waypoint any waypoint preceding the gap before a VTF approach, the Activate Approach LSK will perform and activate leg to the FAF waypoint and the VTF gap will be retained (IFD may or may not retain a published dog-leg inbound to the FAF).
As I understand the original scenario, had Speedbird1 used the Activate Approach LSK while the active waypoint was T82, the result would have been identical to the original described direct-to CIRIX result because the active waypoint was T82 (the airport the approach was based on). 

While not a technique I'm a personal fan of: in this scenario the cleanest way I can think of to "tidy-up" the route would have been to clear the gap either before performing the direct-to CIRIX or after crossing CIRIX.
Thanks for that clarification.  I was thinking #1 since that is the example here, but important to have those distinctions made.
Bob
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Originally posted by brou0040 brou0040 wrote:

We are going to continue to see these questions as new people continue to buy IFDs.  Sure, you can explain the purpose, that is not my point.  My point is that this isn't a new question and will be asked many times again.  If the IFD modified the route but maintained the current navigation, this issue could be reduced.  There is nothing that is forcing the IFD to switch from Direct to CIRIX to activating the new leg.  It could connect the waypoints and retain the current navigation of Direct to CIRIX.  I still haven't heard a case for why that is a bad idea.

I think changing this behavior would create a specific exception to the way the IFD handles any route modifications for a very narrow set of circumstances. Currently, the IFD always follows the route based on the pilot's last route entry. In this scenario, the last route entry is the pilot changing the course guidance to the active waypoint (always something to be done with extreme caution) by eliminating the gap. I cannot get onboard with the idea of making a route modification that I don't want the IFD to display on the map or follow. I believe this is more of an active waypoint modification awareness issue than a fault in the IFD logic. 

While gap clearing in this scenario is not a technique I would personally endorse, there were a couple of alternative timing methods to clear the gap without the unintended consequences described. The gap could have been cleared any time before going direct-to CIRIX or cleared any time after crossing CIRIX. 
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This is very good information.  In fact this thread has helped me in MANY ways.  Thank you everyone.

Somewhat OT; however, do Boeing/Airbus guys tend to prefer the IFD over the GTN?  I know this is an Avidyne forum and the answers are somewhat bias but I figured I'd ask an anecdotal question.  
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You’re welcome!

I’ve never personally used any of the GTN products although have some familiarity with them thru videos and discussions with other pilots. I’ve used a few of the G* portable aviation GPS products over the years. I really liked the way the Avidyne IFD was designed and worked since I was introduced to it while researching an avionics upgrade a little over four years ago. 
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Originally posted by Speedbird1 Speedbird1 wrote:

This is very good information.  In fact this thread has helped me in MANY ways.  Thank you everyone.

Somewhat OT; however, do Boeing/Airbus guys tend to prefer the IFD over the GTN?  I know this is an Avidyne forum and the answers are somewhat bias but I figured I'd ask an anecdotal question.  
Glad to hear.  These discussions always help me as well.  We can never know everything we need to know.  Thanks for raising the question.

I've never flown with Garmin, so I don't know.  I do know that Avidyne is marketing into the coporate jet market with a significant improvement in price point.  Also, Avidyne being a true FMS system is similar to what the big iron use.

DRIFT:  I had a friend in the market for a new WAAS GPS.  He went to Garmin at Oshkosh, and asked why he should buy Garmin over Avidyne.  About the only thing the rep said was, Avidyne is an FMS, which is for large aircraft, not GA.  My friend bought an IFD540.
Bob
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I am an "Airbus" guy currently, but have flown Boeing in the past.  I like the 540, I appreciate the elegance.
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If there were one gap related I would like to see the IFD handle differently, it would be to add the ability to close a gap using any point on SID, STAR, or approach. As far as I can tell, those types of gaps that may be closed, can only be closed using the entry / exit / IAF waypoints of the respective procedure. In my world, is not unusual for ATC to issue a clearance from a point mid-STAR to a point on the approach inside the IAF. 

Big Iron FMSs allow this type of routing modification; however, I have not found a clean way to do this on the IFD beyond remembering to perform a direct-to when arriving a the appropriate waypoint. 


Edited by dmtidler - 09 Jul 2020 at 11:40am
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thanks to all for the prior discussion, it has been most helpful.  In setting up my approaches in the IFD540 and allowing for radar vectors, it seems best to load the approach and not activate it due to the coming radar vectors.  What fix should be the next focus?  I have had trouble with focusing on the IAF, then ATC turns me inside that marker.  Thinking the IFD will update itself, but it doesnt, the better focus maybe the FAF , to which I am now directed.  Activate the approach beginning there and all is well. With the great situational awareness we have, flying the radar vectors by hand or by heading bug until the intercept is easily accomplished.  Then you are setup, established on the localizer, intercept the GS and the AP takes over to fly the ILS.  
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When possible I always set up to full approach even when I expect vectors.   Once I am done being vectored and cleared for the approach, I just activate that leg of the approach.  For instance, even though the approach maybe showing an IAF and an IF, if I am vectored to final, I will activate the leg from the IF to FAF, assuming a straight course on final.  In this way, all the intermediate fixes remain on the plan in case ATC changes and clears me direct to a fix.
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Originally posted by Warrenwhis Warrenwhis wrote:

...In setting up my approaches in the IFD540 and allowing for radar vectors, it seems best to load the approach and not activate it due to the coming radar vectors.  What fix should be the next focus?...


Yes, load but do not activate the approach until cleared for it, as mentioned previously.  In answer to your "focus" question:

If you're still enroute, the next fix on your route is your focus.  If you're on radar vectors in the terminal area, your focus switches to the IAF for the planned or expected approach.  If you are told to expect a different approach, load (but do not activate until cleared for) the new approach and once again focus on its IAF.  When you are at last cleared for the approach and told to proceed direct to the IAF, your focus remains on the IAF.  If instead you are vectored to intercept a segment of the approach after the IAF, your focus switches to the fix at the end of that segment - typically the FAF, but sometimes an IF.  But until you get vectors to intercept a segment after the IAF, always be ready to proceed directly to the IAF to commence the approach if so cleared.  Clearance direct to the IAF is always one of the possibilities, which is one of the reasons its best to avoid the "vectors to final" option for loading an approach.

When vectored to a segment after the IAF, "activate" that segment leg so that the IFD knows the end of that segment is the next fix.  Proceed on the vector heading until intercepting the segment, then proceed inbound to that next fix.  If on autopilot, you may be able to select both heading and approach at the same time, in which case the autopilot will fly the vector and turn onto the segment when intercepting.


Edited by Catani - 29 Oct 2020 at 11:03am
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Originally posted by Warrenwhis Warrenwhis wrote:

thanks to all for the prior discussion, it has been most helpful.  In setting up my approaches in the IFD540 and allowing for radar vectors, it seems best to load the approach and not activate it due to the coming radar vectors.  What fix should be the next focus?  I have had trouble with focusing on the IAF, then ATC turns me inside that marker.  Thinking the IFD will update itself, but it doesnt, the better focus maybe the FAF , to which I am now directed.  Activate the approach beginning there and all is well. With the great situational awareness we have, flying the radar vectors by hand or by heading bug until the intercept is easily accomplished.  Then you are setup, established on the localizer, intercept the GS and the AP takes over to fly the ILS.  
Comments?
You've gotten some good answers.  I'd just like to clarify.  Nomenclature is important.

When being vectored to an intermediate segment, do not activate the APPROACH, but rather activate the LEG that is being intercepted.  The best thing to focus on is the leg you are being vectored to.  Then when cleared for the approach, you can just activate the leg being intercepted.

I know you understand, but your statement: "Activate the approach beginning there" could be misinterpreted by someone else as: "Activate the approach from this position."  This would cause the aircraft to proceed off course direct to the IAF.

A more accurate way to state it would be: "Activate the leg being intercepted"
Bob
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yes ,thx that is what I was trying to prevent!
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One thing to realize is that the Activate Approach LSK does not provide any special functionality.  It is simply a shotcut to go direct to the IAF, or, with Vectors to Final selected, it activates the leg to the FAF.

Everything the Activate Approach shortcut accomplishes can be done through standard Direct-To and Activate Leg actions.  There are never any circumstances where it is mandatory to select it.  It is simply a convenience.

From the Pilot's Guide:
6-16 Navigation
TIPS AND TECHNIQUES
FMS Philosophy
The FMS treats the flight plan as a continuous sequence of legs, regardless of whether they are part of a terminal area procedure or are in the enroute structure.
Bob
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