How many ACTUAL LPV approaches do you do?

[jaylw314]

If I was not able to get into KSMO with the marine layer, my wife would not have approved of the plane.  Even if we only fly there 3-4 times a year, that remains its primary mission, so the inability to fly that LPV approach would have meant I'd be sitting on the ground now.  I think that is well worth the cost difference between the 530 and 530W of 4% of the plane

[Andy95W]

4 hours ago, cliffy said:

So  not many who have invested in full LPV capability use it so why all the histrionics about a guy wanting to save money by using a non WAAS GPS to keep the costs down as a new airplane owner?

He could do a lot of IFR training with his ILS, VOR and non WAAS GPS. For some (a notable few) the full WAAS capability might be needed but it isn't really required especially for a new IFR guy trying to keep costs down and stay alive at the same time. 

Again, nice to say you have full LPV capability but if you don't use it regular what did you spend the money for? Bragging rights? Think again about a low time, new IFR rated pilot trying to "learn" IFR work and thinking he can go into <500 ceilings all the time just because he has a WAAS GPS. Not the brightest thinking to promote. Maybe I've just seen too many smoking holes in my career

BTW, done all the 200& 1/2 and 600 RVR Autolands I ever want to do. 

I'm split right in the middle about this.

Is WAAS/LPV better?  Absolutely.  Is it necessary?  That depends on the pilot/owner.  (For me- no.)

I also disagree with Paul Kortopates' determination that a new instrument pilot without a WAAS box will "only be getting less than half of the training" needed to fly with one.  Instrument training takes a minimum of 40 hours.  Do you expect me to believe it took you 20 hours to learn the transition from basic GPS to WAAS and from LNAV to LPV?  No, it probably took 1-2 hours.  Saying "half" is unconvincing hyperbole.

And Cliffy- we're now doing CAT III to 300 RVR.  The approach and autoland are the same, but the taxi in is now the most difficult part.  Briefing the taxi takes more time than briefing the approach.

[cliffy]

Ya I retired 13 years ago. Was doing 600 RVR in 727s 25 years ago with manual throttles. Did the 600 stuff in an Airbus also. 600 taxi for real was bad enough can't imagine trying to find the terminal at KDEN in 300. :-) WOW!

[JohnB]

I use LPV for my approaches pretty much all of the time, in IMC and VMC conditions when available. Since I have a secondary, if available, ill put the ILS in as a secondary backup in case of GPS signal failure or degradation. I prefer the LPV approaches, as if you use ILS as your primary and you're navigating by GPS, you need to remember to change your CDI back and forth which is not a huge ordeal, but one extra step in doing a missed approach which you don't have to do if flying an LPV.

[takair]

I upgraded my 430 to WAAS when they first offered it.  I don’t shoot that many approaches to low minimums anymore, but our airport has been undergoing upgrades and for the past 6 months, LPV has been our only option.  Just two days ago, even with rather high ceilings, it was my only option...so it was worth it.  That said, if I didn’t have it, I either would not have gone or would have waited.  I really do get Cliffy’s point though.  I think we often discourage folks from getting involved because we artificially bump up the cost of entry.  So, while it IS nice to have the option of having WAAS with LPV, some folks can not afford it and are looking for alternatives.  It really comes down to the value proposition.  If the person in question required the aircraft for business and was routinely flying into my airport IFR, then it becomes a requirement.  If someone has a good deal on a basic 430 and they are just looking for an upgrade for basic instrument flying, then why not.  It’s likely better than the previous alternative.  ( for what it’s worth, I don’t recall the original thread that spawned this one).

[alextstone]

10 hours ago, kortopates said:

Boy Cliff, if that's all you think about WAAS, you're really missing the point of what it provides. LPV approaches down to ILS minimums is only the tip of iceberg. And just because they go down to 200' and 1/2 mile doesn't mean we should set our personal minimums that low either. You're far more experienced than I have had much more training and I realize from reading your post that regardless of your expertise and knowledge you would set conservative minimums within the capabilities of your equipment and your proficiency - as do most of us that wish to avoid the smoking hole you referred too. 

But what your missing about WAAS is that we no longer need an ILS to get a glide slope. Of course WAAS adds either a real glide slope in the form of LPV or LNAV/VNAV. But it also adds Advisory glide slope in the form of LNAV +V, and LP +V which when available allow us to fly the calculated descent angle on the chart to fly a stabilized descent or perhaps what you did in the airlines as CDFA or Continuous Descent from the Final Approach. Of course its well proven that a stabilized descent or CDFA is much safer for us to fly than the Dive and Drive method. Its WAAS that automates this concept for us in the GA world to fly these easily with a Advisory Glide slope. (See AC 120-08) So WAAS adds in addition to capability is also lot of added safety to GA pilots by offering us so many more options over the older legacy approaches with the ability to fly NPA in a stabilized CDFA approach with real or advisory vertical guidance. Which is especially good for us since ILS's are not all that common at our GA airports. 

But I disagree about a new instrument pilot getting a good IFR training and background based on a LNAV only GPS. GPS navigation and approaches are far more complicated than old the legacy ground based approaches but they are much easier to fly which I'll argue adds to safety. But my point is there is so much to learn with GPS Nav and procedures that without a WAAS box you'll only be getting less than half the training of what you'll need with one.   

So if you look at WAAS for only LPV minimums you're not seeing the bigger picture of what its all about.

Good explanation.  You just nailed it! 

[M016576]

On 12/13/2018 at 2:03 PM, thinwing said:

On coastal destinations like Monterey,little river,Arcata,Crescent City,Half moon Bay..Lpvs are main approach I use to get into 500 ovc airports  due to coastal fog.Two of these have Vor/DME or ILS/DME...I guess 5 or 10 a year

I’ll add Astoria to that list- their ILS only goes 1 way- but the LPV can be had if the winds favor RWY8.  Also subject to coastal wx, despite being a little inland.

[cbarry]

Heck, some of us out here, even prior to getting the IFR rating, made sure our aircraft are maintained in good IFR inspection status!  Also, I even upgraded my panel mounts to WAAS prior to getting my IFR!  I guess it never hurts to be prepared and to set goals to pursue and meet for ourselves and our aircraft!

 

Edited December 16, 2018 by cbarry

[Hank]

16 minutes ago, cbarry said:

Heck, some of us out here, even prior to getting the IFR rating, made sure our aircraft are maintained in good IFR inspection status!  Also, I even upgraded my panel mounts to WAAS prior to getting my IFR!  I guess it never hurts to be prepared and to set goals to pursue and meet for ourselves and our aircraft!

 

Yep, me too. 

[M016576]

11 hours ago, kortopates said:

Boy Cliff, if that's all you think about WAAS, you're really missing the point of what it provides. LPV approaches down to ILS minimums is only the tip of iceberg. And just because they go down to 200' and 1/2 mile doesn't mean we should set our personal minimums that low either. You're far more experienced than I have had much more training and I realize from reading your post that regardless of your expertise and knowledge you would set conservative minimums within the capabilities of your equipment and your proficiency - as do most of us that wish to avoid the smoking hole you referred too. 

But what your missing about WAAS is that we no longer need an ILS to get a glide slope. Of course WAAS adds either a real glide slope in the form of LPV or LNAV/VNAV. But it also adds Advisory glide slope in the form of LNAV +V, and LP +V which when available allow us to fly the calculated descent angle on the chart to fly a stabilized descent or perhaps what you did in the airlines as CDFA or Continuous Descent from the Final Approach. Of course its well proven that a stabilized descent or CDFA is much safer for us to fly than the Dive and Drive method. Its WAAS that automates this concept for us in the GA world to fly these easily with a Advisory Glide slope. (See AC 120-08) So WAAS adds in addition to capability is also lot of added safety to GA pilots by offering us so many more options over the older legacy approaches with the ability to fly NPA in a stabilized CDFA approach with real or advisory vertical guidance. Which is especially good for us since ILS's are not all that common at our GA airports. 

But I disagree about a new instrument pilot getting a good IFR training and background based on a LNAV only GPS. GPS navigation and approaches are far more complicated than old the legacy ground based approaches but they are much easier to fly which I'll argue adds to safety. But my point is there is so much to learn with GPS Nav and procedures that without a WAAS box you'll only be getting less than half the training of what you'll need with one.   

So if you look at WAAS for only LPV minimums you're not seeing the bigger picture of what its all about.

I am on the fence on this one.  On one hand- it’s always best to “practice how you play.” So doing the initial training (with an instructor) with the full capability of what you intend to fly is certainly best.

on the other hand- if the cost to attain a WAAS gps would be such that it would impact training dollars- then I’d say it’s better to have additional training, in a non-waas gos equipped airplane.  Honestly- the training to learn how to fly a LPV or LNAV is very simple once you understand all the other principles of IFR flight- so upgrading one’s skill set wouldn’t be like having to start entirely over- it’s more like 1-2 flights and a little ground instruction.

heres the *real* difference I see between WAAS and non-waas these days... the interface.  The IFD and GTN waas units are light years more user friendly than the 530/480/430 of yesteryear.  I would not “pay-up” for a 530W or a 430W... if I found a bird with a regular 430/530 that had the bones I was looking for- I’d buy it, then when I had the money to go WAAS- I’d buy an avidyne, replace the antenna, slide the unit in, sell the old gps and be done with it.

the biggest upgrade one gets out of these new WAAS gps’s isn’t related to lowering approach minima... it’s about ease of use and simplicity in navigation IMO.

Edited December 16, 2018 by M016576

[Wayne Cease]

14 hours ago, cliffy said:

So  not many who have invested in full LPV capability use it so why all the histrionics about a guy wanting to save money by using a non WAAS GPS to keep the costs down as a new airplane owner? 

Don't get that.  Yes a WAAS GPS is better, but a non-WAAS GPS is perfectly fine.  They are getting a bit long in the tooth, so I don't know that I would buy a used one, but immediately swapping one out in a plane doesn't need to be in everyone's plan.

14 hours ago, gsengle said:

Because you don’t need it until you need it.
 

^ There is that.  I flew an Angel Flight mission a couple of years ago where I had to go over to a nearby airport, with slightly better weather as the ILS was down for repairs and the plane didn't have WAAS so I could only do the standard RNAV not the LPV portion.  Got a brief glimpse of the runway as I was climbing on the missed.     Didn't have to wait too long, but I wouldn't have had to wait at all if the plane had a WAAS GPS in it.

 

[Andy95W]

1 hour ago, takair said:

our airport has been undergoing upgrades and for the past 6 months, LPV has been our only option.  Just two days ago, even with rather high ceilings, it was my only option...so it was worth it.  That said, if I didn’t have it, I either would not have gone or would have waited.

I've never seen an LPV only approach, only RNAV/GPS approaches that have LPV minima in addition to LNAV (but obviously I haven't seen every approach to every airport).  I think it's likely that the approach you flew two days ago with rather high ceilings would have been perfectly useable for me with my non-WAAS GPS, but of course using the LNAV numbers.  Kind of like flying the ILS but only descending to the LOC only minimums.

Of course, the LPV is safer- anytime you add vertical guidance it's going to add safety. 

[M016576]

14 minutes ago, Andy95W said:

 

Of course, the LPV is safer- anytime you add vertical guidance it's going to add safety. 

I would actually argue the opposite...they are equally safe, and if anything,  with vertical guidance- a mistake could leave you trending lower into terra firma or obstacles...where as with a non-precision approach, or on a mda- you *should* be level, well above potential obstacles/terrain.

Edited December 16, 2018 by M016576

[takair]

41 minutes ago, Andy95W said:

I've never seen an LPV only approach, only RNAV/GPS approaches that have LPV minima in addition to LNAV (but obviously I haven't seen every approach to every airport).  I think it's likely that the approach you flew two days ago with rather high ceilings would have been perfectly useable for me with my non-WAAS GPS, but of course using the LNAV numbers.  Kind of like flying the ILS but only descending to the LOC only minimums.

Of course, the LPV is safer- anytime you add vertical guidance it's going to add safety. 

Yup, you are right!  Got loose with my terminology.  What I meant is that we currently don’t have any earth based guidance systems.  No ILS and no NDB.  In fact, you could get in with an older non-WAAS approved GnS-430. So, to answer Cliffy’s original question and to your point..in my approach a couple of days ago, I still would have gotten in without WAAS.

 

[Bug Smasher]

Lots of opportunities for LPV approaches in coastal California and Oregon. It's especially useful at fields with no ILS.

[kortopates]

I'm split right in the middle about this.

Is WAAS/LPV better?  Absolutely.  Is it necessary?  That depends on the pilot/owner.  (For me- no.)

I also disagree with Paul Kortopates' determination that a new instrument pilot without a WAAS box will "only be getting less than half of the training" needed to fly with one.  Instrument training takes a minimum of 40 hours.  Do you expect me to believe it took you 20 hours to learn the transition from basic GPS to WAAS and from LNAV to LPV?  No, it probably took 1-2 hours.  Saying "half" is unconvincing hyperbole.

And Cliffy- we're now doing CAT III to 300 RVR.  The approach and autoland are the same, but the taxi in is now the most difficult part.  Briefing the taxi takes more time than briefing the approach.

Fair enough Andy. I say that because although the mechanics of flying them aren't hard but it takes typically longer than 20 hrs for most to master the buttonology on the boxes. Plus there are 6 different types of GPS Approaches not counting RF legs that a waas box is capable of and getting into the nuances of each and their differences takes time. The written is catching up but instruments students are still sorely lacking in knowledge on these.

The beauty is that flying them is much easier than say an old DME arc to an ILS once we have the GPS, but now mastery of the avioincs is much more complicated and we have many more versions of NPA's to understand.

In fairness, I can't really separate the training time in mastering a non-waas box versus a waas box because really any approach capable GPS is going to take a lot of time to become proficient on. So perhaps my remark about half a ticket should be left for ground based only approaches vs ground based + GPS. Still though, WAAS adds much more complexity to understanding all the different options and how they are different along with the many charted subtleties not found in precision approaches (eg Advisory vs VNAV, VDP's, VGSI not coincident with GS and many more, PT's and many more...) LNAV, the only non-waas approach is just one of the 6.

 

 

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[kortopates]

I would actually argue the opposite...they are equally safe, and if anything,  with vertical guidance- a mistake could leave you trending lower into terra firma or obstacles...where as with a non-precision approach, or on a mda- you *should* be level, well above potential obstacles/terrain.

The FAA claims the use of a glide slope or always using the CDFA technique I referenced in the above AC is "safer" than the old "dive and drive" method we used to fly NPA's. This is the whole basis of Advisory Glide slope since it's automated the charted descent angle on the IAP.
But thank you for making my point - it's no where near enough for a student to just be able to mechanically fly these different procedures. The pilot needs to understand their differences and meanings to avoid the many gotchas that are possible; especially following the advisory Glide slope below MDA. Some may recall that a few years ago the FAA went wild removing charted descent angles from the database procedures (actually re-coding them to zero) on many approaches where the VGSI was not co-incident to GS because pilots were screwing up. So that would be in point in favor of your argument - if pilots blindingly follow a GS. But with the knowledge of how to fly these approaches the CDFA technique to fly a stabilized approach with advisory Glide slope is definitely a safety enhancement.

But where the box has simplified the mechanics of flying difficult approaches the knowledge required and the avioincs to do so are far more complicated than ever before for our GA pilot. As an example, perhaps the most challenging aspect of instrument flying before GPS was partial panel, but with WAAS it's very easy to fly approaches to ATP standards with the same otherwise legacy 6 pack panel. That’s a huge safety enhancement right there.

Working with a lot of pilots that were originally trained with only ground based nav (like myself) it's no surprise to me that they still tend to rely on ILS approaches rather than GPS since they haven't yet mastered their avioincs nor become educated on all the different GPS approaches. They probably make up half of the folks I work with.


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[M016576]

3 hours ago, kortopates said:

But where the box has simplified the mechanics of flying difficult approaches the knowledge required and the avioincs to do so are far more complicated than ever before for our GA pilot. As an example, perhaps the most challenging aspect of instrument flying before GPS was partial panel, but with WAAS it's very easy to fly approaches to ATP standards with the same otherwise legacy 6 pack panel. That’s a huge safety enhancement right there. 



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Exactly.  And thank you for proving my (previous) point- No longer do we have to visualize our position in relation to the approach/runway... the GTN/IFD... and all our iPad’s... show us exactly where we are, to include the approach plate over-laid on the low or high chart itself.  It’s not really the WAAS receiver itself that does this for us, though... it’s the user interface/computing power associated with the individual unit.  That’s the true power of these units, I think, at least for GA- they give a pretty decent, simple, modern type user interface to a skill set that used to be somewhat specialized and not all that intuitive to the uninitiated.

[larryb]

Pay me now or pay me later. WAAS is the future. If you have a legacy panel and you invest in a non WAAS solution today you will just redo it in a few years. With the cost of avionics labor it just does not really pay to “do it on the cheap.” It will cost more in the long run.

[gsxrpilot]

10 hours ago, larryb said:

Pay me now or pay me later. WAAS is the future. If you have a legacy panel and you invest in a non WAAS solution today you will just redo it in a few years. With the cost of avionics labor it just does not really pay to “do it on the cheap.” It will cost more in the long run.

And this is always my point. Obviously everyone has a budget that becomes a limiting factor. But with proper research and information you often find that for a little extra spent now, you can save a significant expense down the road. And even if you will never use WAAS, having it will make the plane much easier to sell to the next guy down the road. 

[Marauder]

And this is always my point. Obviously everyone has a budget that becomes a limiting factor. But with proper research and information you often find that for a little extra spent now, you can save a significant expense down the road. And even if you will never use WAAS, having it will make the plane much easier to sell to the next guy down the road. 

I think the other half of this argument is how long is a non-WAAS unit going to be supported?


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[thinwing]

On 12/17/2018 at 3:03 PM, kortopates said:

The FAA claims the use of a glide slope or always using the CDFA technique I referenced in the above AC is "safer" than the old "dive and drive" method we used to fly NPA's. This is the whole basis of Advisory Glide slope since it's automated the charted descent angle on the IAP.
But thank you for making my point - it's no where near enough for a student to just be able to mechanically fly these different procedures. The pilot needs to understand their differences and meanings to avoid the many gotchas that are possible; especially following the advisory Glide slope below MDA. Some may recall that a few years ago the FAA went wild removing charted descent angles from the database procedures (actually re-coding them to zero) on many approaches where the VGSI was not co-incident to GS because pilots were screwing up. So that would be in point in favor of your argument - if pilots blindingly follow a GS. But with the knowledge of how to fly these approaches the CDFA technique to fly a stabilized approach with advisory Glide slope is definitely a safety enhancement.

But where the box has simplified the mechanics of flying difficult approaches the knowledge required and the avioincs to do so are far more complicated than ever before for our GA pilot. As an example, perhaps the most challenging aspect of instrument flying before GPS was partial panel, but with WAAS it's very easy to fly approaches to ATP standards with the same otherwise legacy 6 pack panel. That’s a huge safety enhancement right there.

Working with a lot of pilots that were originally trained with only ground based nav (like myself) it's no surprise to me that they still tend to rely on ILS approaches rather than GPS since they haven't yet mastered their avioincs nor become educated on all the different GPS approaches. They probably make up half of the folks I work with.


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And that was me prior to 2009....all prior 400 hrs actual IMC were in standard six pack,non IFR rated GPS and Loran...no moving map ils,vor and occasional adf approachs.Wife found me an ex AF u-2R pilot who took 5 hours to square me away on Garmin G500/530W equipment