Easiest way to bypass HILPT on GNS-430?

[chemgeek]

Flying a familiarization flight with my G5s and GNS-430 (and the new GPS 35 approach at KVGC with a HILPT instead of the old T-entries) I discovered that the GNS-430 will command the G5s to fly the HILPT whether or not it is required. (When approaching the IAF from the south, the HILPT is not required.) My solution, after brief consideration, was to simply delete the hold from the procedure prior to reaching the IAF, which the GNS-430 accepted. (Just for fun, I tried to delete one of the other approach waypoints, and the GNS-430 will not allow you: sorry, Dave, I can't do that...)

Is there an easier way of bypassing the HILPT, or is deleting the unnecessary hold the easiest way of managing this situation? I suppose it is possible to manually activate the final approach leg when crossing the IAF to bypass the hold, but that seems clumsy in terms of timing and button pushing. Deleting the hold seemed cleaner. I didn't try to see if the GPS would auto-sequence past the hold if I hand-flew the approach (which is how I often fly this approach anyway), but I wanted to see how the G5s would fly the coupled approach. They do a pretty good job, actually.

 

[MauleSkinner]

Direct-direct to the fix after it will line up the course.

 

[chemgeek]

Direct-direct to the fix after it will line up the course.

Yes, activating the next leg at the IAF should bypass the hold, but that's a lot of buttons to punch at the IAF, meanwhile the G5s and AP are preparing to enter the hold? Deleting the hold was clean, could be done in advance, and the GPSS roll steering cleanly transitioned to the FAF.

 

[flyingron]

On the 480 just pushing SUSP lets you go on with the plan.

 

[chemgeek]

I did find an old web discussion of this issue and it appears there are two solutions: manually delete the hold (as I did) or to wait for the SUSP annunciation and hit OBS to bypass the hold. You can also select VTF in a pinch, but it may delete a bunch of waypoints on the approach prior to the FAF, which could compromise situational awareness in some cases. BTDT when ATC changes its mind in the middle of an approach sequence.

I kinda like the manual deletion method as you can do this in advance while transitioning direct to the IAF and the AP won't get confused if you are using it.

It's good to figure this out while training and not IFR, although I would have eventually figured out one or the other. Learn something every flight.

 

[James331]

Activate the leg on the flight plan.

Select waypoint
Menu
Activate leg

 

[MauleSkinner]

Yes, activating the next leg at the IAF should bypass the hold, but that's a lot of buttons to punch at the IAF, meanwhile the G5s and AP are preparing to enter the hold? Deleting the hold was clean, could be done in advance, and the GPSS roll steering cleanly transitioned to the FAF.

why wait until you’re at the IAF?

 

[midlifeflyer]

why wait until you’re at the IAF?

Wants to stay well behind the airplane?

I can think of three solutions (partly a summary) but all three involve being ahead of the airplane.

1. I haven't looked at this approach but most I have seen with an optional hold ask whether you want the hold when you first load it. Just say no.
2. Remove the hold.
3. Activate leg or switch to VTF (at the appropriate point).

My preference is the first two, in large part because they can be done so early.
The last two are probably the fastest when you haven't thought about it in advance, with VTF being slightly faster but activate leg having, I think, an operational advantage.

 

[midlifeflyer]

I did find an old web discussion of this issue and it appears there are two solutions: manually delete the hold (as I did) or to wait for the SUSP annunciation and hit OBS to bypass the hold. You can also select VTF in a pinch, but it may delete a bunch of waypoints on the approach prior to the FAF, which could compromise situational awareness in some cases. BTDT when ATC changes its mind in the middle of an approach sequence.

The catch with using VTF is that it has to be at the right time because of its waypoint deletion in the GNS and some other units, the reason for the AIM advisory against using it and many pilots putting it in their verboten list.

But it can have its place. It is going to be very clear at some point in the sequence that unless there is a situation in which you are going to come off the approach altogether (and have to load the approach all over again anyway), there is no way ATC is going to send you to some other waypoint. And since it is, if I am remembering correctly, only a two tap activity in the GNS, it is the fastest and so can be done pretty late in the sequence. But it really should be done well before then.

I'm personally not a fan of the OBS SUSP method. The timing is poor, typically just as you are preparing to or in the process of reconfiguring for the FAS. That's not when I want to be pushing buttons.

That question of "when" to do things, especially with modern avionics, is an extremely important thing to me. The two sometimes competing values are speed and efficiency. Which solution takes less activity (speed) and which can be done at a point when other workload is lower (efficiency). That's a bit subjective so my solution might be different than yours.

 

[chemgeek]

Wants to stay well behind the airplane?

I can think of three solutions (partly a summary) but all three involve being ahead of the airplane.

1. I haven't looked at this approach but most I have seen with an optional hold ask whether you want the hold when you first load it. Just say no.
2. Remove the hold.
3. Activate leg or switch to VTF (at the appropriate point).

My preference is the first two, in large part because they can be done so early.
The last two are probably the fastest when you haven't thought about it in advance, with VTF being slightly faster but activate leg having, I think, an operational advantage.

As usual, Garmin gives you eleventy-seven ways of doing a particular task. I was expecting option #1, but it did not appear in my arming sequence. I may play around a bit to see if it shows up if you Load vs. directly Activate the approach. #2 works fine and keeps you ahead of things and doesn't confuse the autopilot, if using it. The issue could also be a database error, where the hold prompt is missing. This is a brand-new approach design, where the FAA deleted the T-entry IAF points of the old approach and replaced it with a HILPT. The HILPT also serves as the missed approach hold for the opposite runway approach. Airspace efficiency, I suppose. I liked the old T-entries.

Anyway, this is all good stuff to know in advance. I'll probably review this with my CFII as well during my upcoming IPC.

 

[benyflyguy]

I’d have to go up and play but couldn’t you just load approach and select VTF once on intercept course and it will bypass the PT.

 

[chemgeek]

I’d have to go up and play but couldn’t you just load approach and select VTF once on intercept course and it will bypass the PT.

You could, but VTF is a kludge that deletes waypoints outside the FAF, which is detrimental to situational awareness. Plus, if you are cleared to the IAF, flying a intercept to the final approach course isn't exactly the correct clearance. Manually deleting the hold maintains all waypoints, and programs the correct routing. My experience in flying the GNS-430 is that VTF gets you into trouble as often as it simplifies things. About 1 time in 2 ATC promises a VTF on a GPS approach, it gives me an amended clearance to one of the fixes which are now no longer displayed in VTF. This results in a lot of button mashing to reload and activate the approach and sometimes select an intermediate waypoint.

 

[midlifeflyer]

As usual, Garmin gives you eleventy-seven ways of doing a particular task.

LOL. Most software I've used in the past 40+ years has done exactly that. I still prefer to use shortcut keys for formatting text to mouse clicks. think pretty clearly, if the prompt to skip the PT isn't there (and who knows, maybe it went away at some point in software upgrades - what does your User Guide say about it?), deleting it right after loading is the way to go. The artificially compressed training environment aside, you are typically loading an approach long before you need to fly it. Pretty much as soon as you know the weather, especially at a nontowered airport where there is no "default" approach and you are going to be asked what you want. Those extra button presses should be a non-event.

 

[FORANE]

I have deleted it then wondered how to get it back if my clearance changed to the hold.
Guess it would involve reloading the approach.

 

[benyflyguy]

You could, but VTF is a kludge that deletes waypoints outside the FAF, which is detrimental to situational awareness. Plus, if you are cleared to the IAF, flying a intercept to the final approach course isn't exactly the correct clearance. Manually deleting the hold maintains all waypoints, and programs the correct routing. My experience in flying the GNS-430 is that VTF gets you into trouble as often as it simplifies things. About 1 time in 2 ATC promises a VTF on a GPS approach, it gives me an amended clearance to one of the fixes which are now no longer displayed in VTF. This results in a lot of button mashing to reload and activate the approach and sometimes select an intermediate waypoint.

As I typed it I realize that I went up with safety pilot to hammer out these issues. You are right VTF- causes more problems then solutions. You always think it’s going to be a great idea- then it doesn’t work out.

 

[azure]

The 480 has something called FlyLeg, that lets you skip to a particular leg in the FP (and intercept the course if you're not already aligned with it). Does the 430 not have something similar?

 

[midlifeflyer]

The 480 has something called FlyLeg, that lets you skip to a particular leg in the FP (and intercept the course if you're not already aligned with it). Does the 430 not have something similar?

Yes, it has been mentioned by a few people. "Activate leg."

 

[EdFred]

When I load up an approach with a 430W it always asks me "Hold at xxxxx?" and I can answer, yes or no. Are you not getting that option?

 

[chemgeek]

When I load up an approach with a 430W it always asks me "Hold at xxxxx?" and I can answer, yes or no. Are you not getting that option?

Nope. I wonder if it is a database error? Maybe it will get corrected in the next cycle. This is a newly re-designed approach, and the HILPT is a new feature. At least is is correctable issue.

 

[EdFred]

Nope. I wonder if it is a database error? Maybe it will get corrected in the next cycle. This is a newly re-designed approach, and the HILPT is a new feature. At least is is correctable issue.

Do you get that option to Hold/not hold on other approaches you load? Or is it only this one that is wonky?

 

[chemgeek]

Do you get that option to Hold/not hold on other approaches you load? Or is it only this one that is wonky?

I'll have to try loading some other approaches with HILPTs. I haven't noticed this issue before, probably because none of the RNAV approaches I've flown have included them. ILS approaches yes, but I usually hand fly those. When using the AP, the issue will arise as the AP shows you what it thinks it should do.

 

[RussR]

I've experienced this a few times, where the 430 doesn't ask if you want to do the hold, when you are clearly coming from a NoPT direction.

Every time at BWD, RNAV (GPS) RWY 17.
Just the other day at RQO RNAV (GPS) RWY 35.

Note that both of these have fairly recent amendment dates.

Not sure if there is a difference between getting your database from Garmin or from Jeppesen (neither airplane in these cases was mine, and I do not know the database supplier they use).

 

[midlifeflyer]

I've experienced this a few times, where the 430 doesn't ask if you want to do the hold, when you are clearly coming from a NoPT direction.

Every time at BWD, RNAV (GPS) RWY 17.
Just the other day at RQO RNAV (GPS) RWY 35.

Note that both of these have fairly recent amendment dates.

Not sure if there is a difference between getting your database from Garmin or from Jeppesen (neither airplane in these cases was mine, and I do not know the database supplier they use).

Certainly a possibility. There are a number of differences between the two databases.

 

[midlifeflyer]

This is from the 2016 edition of the User Guide. Confusing!

 

[aterpster]

This is from the 2016 edition of the User Guide. Confusing!

View attachment 81417

Suppose "GPS approach" was referring to overlays?

 

[midlifeflyer]

Suppose "GPS approach" was referring to overlays?

Beats the heck out of me. They've said "overlay" when they meant overlay. And this is the 2016 edition - weren't overlays gone by then?

Sounds more like "you are given the option except when you aren't" which is exactly what some have experienced.

 

[chemgeek]

This is from the 2016 edition of the User Guide. Confusing!

View attachment 81417

The most recent downloadable pilot guide for the GNS-430W has the same cryptic notation. I have no idea what Garmin intends the difference to be between "RNAV GPS" and "GPS" approach. Possibly distinguishing a true RNAV approach vs. an "overlay" non-precision approach, but who knows.

However, you slice it, configuring whether or not to fly the HILPT is clear as mud in the operating manual. So best to be forewarned and prepared. There are apparently several options you can prepare to take if you don't need to fly the hold from your approach entry:

1. Decline to fly the hold if prompted (preferred; can be done well in advance of the IAF and maintains proper AP navigation continuity)
2. Delete the hold segment of the approach (can be done well in advance of the IAF and maintains proper AP navigation continuity)
3. Activate the next segment of the approach when crossing the IAF (clumsy if the AP is engaged: it may initiate hold entry maneuvers before crossing IAF; less clumsy if hand-flying the approach)
4. Activate VTF (not recommended unless under VTF direction of ATC; some intermediate waypoints will be deleted from the flight plan, and the autopilot will not direct you to the IAF if that is your clearance. I normally load the full approach even if being vectored to final by ATC. It's easy enough to activate the intercepted leg when you arrive on the final approach course. That way if ATC changes its mind and clears you to an IF or the IAF instead of vectoring to the final approach course you are not left hanging.)

Since the FAA saw fit to replace the T-entry IAFs with a HILPTs for all the RNAV approaches to my home field, this is good to know. It is very rare I will get vectors to final from Syracuse Approach, especially for the RWY 35 approach, where radar coverage may not be ideal at the IAF. They usually send you to one of the IAFs and expect you to fly via own nav. That's OK by me, anyway, as flying the full approach may actually be a lower pilot workload when the AP is engaged.

Cheers.

 

[RussR]

Suppose "GPS approach" was referring to overlays?

Although I don’t claim to know what Garmin means, they could mean that the sequencing is treated differently between a RNAV (GPS) approach, like RNAV (GPS) RWY 35, and a GPS approach, like GPS RWY 35, which is the much older terminology.

According to the latest FAA IFP inventory summary, there are still 46 GPS approaches in the U.S., such as the KIZA GPS RWY 8. Note it’s not a RNAV (GPS) RWY 8.

https://aeronav.faa.gov/d-tpp/1913/05730G8.PDF

 

[aterpster]

Beats the heck out of me. They've said "overlay" when they meant overlay. And this is the 2016 edition - weren't overlays gone by then?

Not all of them. My favorite IAP at KEMT was an overlay until this past Dec 5. The other IAP at KEMT was an overlay until a year, or so, ago.

 

[aterpster]

According to the latest FAA IFP inventory summary, there are still 46 GPS approaches in the U.S., such as the KIZA GPS RWY 8. Note it’s not a RNAV (GPS) RWY 8.

https://aeronav.faa.gov/d-tpp/1913/05730G8.PDF

I'm familiar with that airport and have flown that approach in the Garmin trainer. It acts no different than a similar approach with RNAV in the title. It is an RNAV approach in any case.

Also worth noting, the VOR approach at KIZA is still an overlay. That doesn't comply with policy since Runway 8 has the GPS IAP (which quacks "RNAV").