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Do I really need NAV, really?

gotyoke

Well Known Member
I'm not yet instrument rated, and I wont have to make this decision for at least a year, but there's no harm in thinking about this now. Also, I'm referring to Garmin for this question simply out of familiarity, but I'm not settled on them.

I'm just starting building and I'm leaning toward a fairly minimal one G3X-based glass panel. I like the idea of the GNX 375 (Navigator+ADS-B transponder), which does not have VHF NAV (VOR/ILS). Basically, with the exception of maintaining currency, I see myself doing GPS IFR exclusively. If there is a GPS outage in IMC conditions, I likely just won't want to fly.

Adding VHF NAV to my idea of an ideal panel is at least a $3,500 investment (GTR 200 to GNC 255A, much more if going with the GTN 650Xi, because then I need a seperate ADS-B transponder). Seems a lot to maintain currency for a mode of IFR flying I don't intend to do. Instead, I'd just rent from a local club, or find a buddy.

So the real question: Is there some other rationale that I should consider that might convince me to fork out thousands more $$$ to add VHF NAV?
 
Well the problem is you could have a GPS failure for a variety of reasons while enroute. Bad juju in my book. For me, I like having options in case of enroute failure or if there's something like a GPS NOTAM'd outage along my route. This has happened to me on number of flights and although I never lost the GPS signal, I wouldn't have launched without a VOR/LOC/GS backup. YMMV...
 
Is there some other rationale that I should consider that might convince me to fork out thousands more $$$ to add VHF NAV?

Well... no, not really.

There is the hypothetical of what do you do if your airborne IFR GPS fails, or if the GPS satellite network fails. For example, some truckers have been known to carry GPS jammers so that their company can't track them, and when they drive by an airport...

Personally, I think the odds of the whole GPS constellation failing are remote, and even if you're down to minimal coverage, accuracy should be good enough for an approach, even if the accuracy is not up to par.

Other folks will probably have good anecdotes to add.

If you do your instrument training in the RV, I wouldn't count on GPS skills helping you fly non-GPS, i.e., VOR. With VOR, you have scallopy signals and have to keep track of time rather than read out distance directly.

My RV-9A came with a GTN650, so I've got GPS and VOR, but I've hardly used VOR, even for training. ILS, yes.

But I have practiced standby flying with only the G5 and an aera 660, which has geo-referenced approach plates. It wasn't all that hard to improvise an approach, which is what would be required in case of total electrical failure.
 
Sure nice to have some redundancy. Now if you were solid VFR you could use a paper map and pilotage, but even so the option is good to have.

And there's nothing to stop you from buying a non-Garmin VOR system, even used, and installing that. You'll have room. Kind of old school but they work. The very first entry on one site had a King KX-155 with a KI-208 for $1,600 asking. No idea about the unit, the model or the price, but right there you can save a few bucks. Probably a lot more if you look around.

It wouldn't be controlled from or displayed on your big screen, but that's a training or familiarization matter, not a show-stopper.

Dave
 
Nothing wrong with simple

As stated no reason at all. I think any single EFIS will meet the requirements for minimum equipment for VFR. Redundancy is good, even a whiskey compass in that case. I friend built a nice basic G3X panel, it has all the nav, autopilot needed for VFR and it is so easy to fly - - just no approaches.

Although, if you are investing so much labor (instead of managing your investments and mowing the grass) in a really nice RV14A, then a nice IFR panel is really not much (%-wise) more. Or, nothing says you can't plan ahead for an upgrade to fill out the panel when you start- just wire some connectors for the 650 (etc) so it will be easy to add. You won't want to spend (as) much working time on the plane when it is finished. :eek:
 
It depends . . .

This is a subject that I always find interesting and it will likely generate 3+ pages.

I just re-did my airplane’s entire avionics, electrical, and lighting. My airplane is very light IFR and has only a GNX375 for navigation / approach.

Just as a point of reference, to simply understand where I am coming from on my opinion. Opinion’s right? Please don’t take this as someone throwing their log book around because they think they’re an expert. I am not. That being said, I have a few hours in the book. Professional for 29 years, airline for 25 years, CFII/MEI for 29 years, 23K plus hours in the book, all civilian, and lots of time in bug smashers, but only about 1300 hours in single engine airplanes with about 200+ in RV6/8.

I personally look at flying IMC in RV’s like this; I can, if I have to, but I try to avoid it. Personal minimums are 1000/2. I want a fighting chance when I come out of the clouds with the engine stopped. Now, flying IFR? IE filing IFR to work in the system, flying to say an airport underneath a class B shelf to make the experience a little more efficient, mostly VMC? My ride will do the trick and I can always fall back to dead reckoning if everything goes south and I am down to the G5 and the ipad.

Lots of folks on this web page and YouTube have a far greater level of comfort in flying IMC. There will be hundreds of pages about the “impossible turn” and how it can’t or shouldn’t be tried, but little concern for hours in the soup. Approaches to minimums, IMC the entire flight with low ceilings below. Even icing. Building airplanes with double and triple redundancy. All the while sitting behind one engine, that when/if it quits, there isn’t a backup battery in the world that’s going to get you home that day. Not my cup of tea, but to each their own. I live around mountains and I am almost always flying over terrain that I may have a hard time successfully pulling off an off airport landing. My flying is not without risk. I fly my machine for fun. But I hope to get out and do some traveling soon and like to have the OPTION if I need it, but my personal RV IFR minimums are not flexible and I will always prefer VMC operations.

The depends part? I would commend anyone for getting an Instrument Rating. It is the best rating to improve your skill and knowledge. You will fly a more precise airplane and have a far better understanding of the system you’re working in. It’s THEE license to learn with. If, like Doug, you intend to use your airplane to move through ratings and gain experience, to possibly take up a second side career. Maybe getting a CFI to do some flying on the weekend on somebody else’s dime. Then I say yes! Outfit it with redundancy, IFR GPS and VOR/ILS at a minimum. Lots of ways to do that. From very expensive to reasonable as some have mentioned. If you’re just traveling for the fun of it, and occasionally needing to file IFR and light IMC with high personal minimums, then GPS only is likely acceptable.

This is simply one opinion. You should continue your due diligence and think about how you are really going to operate your airplane. What your personal comfort level is. As always, this should not be taken as a recommendation and your mileage may vary as they say.
 
Three issues I cared about

GPS can fail or be blocked; though seems rare. What would you do if you were landing in East TX next week and didn't know about the outage. That is a WIDE outage area. I don't know, but doubt ATC would warn you. They would likely expect you to read the NOTAM and suspect we have all skipped this at one time or another as we got sick of reading 100 notams about 200' towers with their lights out of serice.

At some airports, ILS will get you down a good bit lower than LPV. It does seem that many LPV approaches overlaid on ILS runways also have 200 or 250 MDA, but certainly not universal. If you always carry excess gas, you can get around that in many cases.

Surveillance approaches seems to be somewhat rare, so having redundancy gives more options if low on fuel.
Larry
 
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Ask a DPE that would do your checkride. I asked a question similar to this a couple years back and the consensus seemed that you can't take a checkride without NAV as an LPV isn't technically considered a precision approach. So if you plan on doing your training in the plane you build I believe you will want to spend the extra money.

P.S. a second com is not a must but it's pretty dang close for IFR work.

As for me, I just purchased a 430 tray and prewired it into the system. I can now slap either a GNS-430 or IFD-440 in and be good to go. Also have a spot prewired for a G5 as backup.
 
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My opinion: you’re worried about the wrong thing. Remember ‘aviate, navigate, communicate’, in that order? If you are flying in actual IMC and your single EFIS decides to quit, there is a good probability that you will die. IMHO a second, internal battery (or second buss system) EFIS is the first order of business. Now, as to gps only: I have personally watched (I was right sear cfi, pilot was under the hood, vfr) a GTN 650 degrade from LPV to LNAV to a big red X while doing the gps approach into LVK. So it can happen. But if it was imc we could have climbed, talked to atc, figured something out. Something else: the faa still has not clarified the rules, as to whether or not a gps only airplane is suitable for taking the practical flight test. Some DPEs will do it, others won’t.
 
You might look into going with a GNC 430W instead of the newer unit. You could likely pick up a used one and a new transponder for the cost of a new GNX 375. Then you've got VOR/ILS and GPS capability that all interfaces with the G3X.

And to Bob's point, I'd add a G5 as a backup.
 
Lots of opinions. Everyone is different.

I would rather have a GNC355 than the GNX375.

I like the idea of not have lots of devices in one box. IF the Transponder fails, it can be pulled out for repair while I still fly VFR outside ADS-B required airspace.

Yes two devices can be combined into one box and most of the time will save money and panel space.

The Pros and Cons of different configurations ends up being a personal preference to suit each individual.
 
Ask a DPE that would do your checkride. I asked a question similar to this a couple years back and the consensus seemed that you can't take a checkride without NAV as an LPV isn't technically considered a precision approach. So if you plan on doing your training in the plane you build I believe you will want to spend the extra money.
.

The Instrument ACS allows for this. If the GPS is TSO146, you can do it.

Appendix 7 of the Instrument Rating ACS, section VI. Instrument Approach Procedures. Here's the relevant paragraph:

Localizer Performance with Vertical Guidance (LPV Minimums)

Localizer performance with vertical guidance (LPV) minimums with a decision altitude (DA) greater than 300 feet height above touchdown (HAT) may be used as a non-precision approach; however, due to the precision of its glidepath and localizer-like lateral navigation characteristics, an LPV minimums approach can be used to demonstrate precision approach proficiency if the DA is equal to or less than 300 feet HAT.


Before I wrote this reply, I also ran this by a DPE who is both significantly experienced an an RV owner. He would have no problem with administering a checkride that way.

Personally, I prefer to have NAV backup, but that's only because my airplane came with an SL-30 that I am re-using as a second COM and getting NAV backup as a convenient side effect. And the SL-30 is a heck of a piece of kit. But, if I DIDN'T have it, I wouldn't worry too much about not having VHF NAV capability.
 
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Two comments
1. Yes IMHO the SL30 is the best nav ever built. e.g., I can shoot the KSCK LOC 29R with no other nav equipment working. My GRT HX will show the LOC course on the main CDI needle, and the VOR cross fix as an RMI pointer - with both nav signals coming from the SL30. I know of no other nav that can do that. Too bad they’re no longer made.
2. The issue with a gps-only airplane on the practical test is not the precision (or LPV in lieu of) approach. It’s the two non-precision approaches, ‘…each using a different nav aid’. The ACS then lists vor, loc, sdf, gps,…as examples. Problem is gps is only one type. What’s number two?
 
Needing NAV

I almost never use VHF NAV in the real world. As others have suggested, I'd skip the VHF NAV, but get a G5 with the battery backup.

You could get a relatively inexpensive handheld radio that will show a VHF NAV CDI just for peace of mind regarding a "worst case" scenario.

I'm not yet instrument rated, and I wont have to make this decision for at least a year, but there's no harm in thinking about this now. Also, I'm referring to Garmin for this question simply out of familiarity, but I'm not settled on them.

I'm just starting building and I'm leaning toward a fairly minimal one G3X-based glass panel. I like the idea of the GNX 375 (Navigator+ADS-B transponder), which does not have VHF NAV (VOR/ILS). Basically, with the exception of maintaining currency, I see myself doing GPS IFR exclusively. If there is a GPS outage in IMC conditions, I likely just won't want to fly.

Adding VHF NAV to my idea of an ideal panel is at least a $3,500 investment (GTR 200 to GNC 255A, much more if going with the GTN 650Xi, because then I need a seperate ADS-B transponder). Seems a lot to maintain currency for a mode of IFR flying I don't intend to do. Instead, I'd just rent from a local club, or find a buddy.

So the real question: Is there some other rationale that I should consider that might convince me to fork out thousands more $$$ to add VHF NAV?
 
I almost never use VHF NAV in the real world. As others have suggested, I'd skip the VHF NAV, but get a G5 with the battery backup.

You could get a relatively inexpensive handheld radio that will show a VHF NAV CDI just for peace of mind regarding a "worst case" scenario.

Excellent suggestions. (I’d add a dynon D6 or grt mini as less costly possibilities)
I have a very old Sporty’s handheld that only displays the vor radial, as a digital number (no needles). I’ve tried using it on a vor approach (under the hood) and it’s quite doable. You just squint your eyes and pretend it’s an NDB!
 
Excellent suggestions. (I’d add a dynon D6 or grt mini as less costly possibilities)
I have a very old Sporty’s handheld that only displays the vor radial, as a digital number (no needles). I’ve tried using it on a vor approach (under the hood) and it’s quite doable. You just squint your eyes and pretend it’s an NDB!

Archaic electronics definitely have their merits. My RV is VFR only but does have a KX-125. I haven't yet, but I plan to use it for some VOR, LOC, and LDA approaches for currency. Could also be a super cheap VHF backup to a GPS.
 
Two comments
1. Yes IMHO the SL30 is the best nav ever built. e.g., I can shoot the KSCK LOC 29R with no other nav equipment working. My GRT HX will show the LOC course on the main CDI needle, and the VOR cross fix as an RMI pointer - with both nav signals coming from the SL30. I know of no other nav that can do that. Too bad they’re no longer made.
2. The issue with a gps-only airplane on the practical test is not the precision (or LPV in lieu of) approach. It’s the two non-precision approaches, ‘…each using a different nav aid’. The ACS then lists vor, loc, sdf, gps,…as examples. Problem is gps is only one type. What’s number two?

This is where I wish the FAA issued some clearer guidance, because it seems you can read the language of the ACS two different ways:

Task A. - Nonprecision Approach

...Examples of acceptable nonpreicison approaches include: VOR, VOR/DME, LOC procedures on an ILS, LDA, RNAV (RNP) or RNAV (GPS) to LNAV, LNAV/VNAV or LPV line of minima as long as the LPV DA is greater than 300 feet HAT.


It would be possible - as written - to fly an RNAV approach to LNAV/VNAV, an LPV approach as a precision, and then a different LPV as non-precision. The ACS doesn't specify that the navigation sources have to be different, just that the applicant fly precision and non-precision approaches. They leave it up to the examiner's authority, it seems.

EDIT - I have also deigned to run this by a DPE I know who is also an RV owner. Interested to get his take - I'll post it in this thread.
 
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The Instrument ACS allows for this. If the GPS is TSO146, you can do it.

Appendix 7 of the Instrument Rating ACS, section VI. Instrument Approach Procedures. Here's the relevant paragraph:

Localizer Performance with Vertical Guidance (LPV Minimums)

Localizer performance with vertical guidance (LPV) minimums with a decision altitude (DA) greater than 300 feet height above touchdown (HAT) may be used as a non-precision approach; however, due to the precision of its glidepath and localizer-like lateral navigation characteristics, an LPV minimums approach can be used to demonstrate precision approach proficiency if the DA is equal to or less than 300 feet HAT.


Before I wrote this reply, I also ran this by a DPE who is both significantly experienced an an RV owner. He would have no problem with administering a checkride that way.

Personally, I prefer to have NAV backup, but that's only because my airplane came with an SL-30 that I am re-using as a second COM and getting NAV backup as a convenient side effect. And the SL-30 is a heck of a piece of kit. But, if I DIDN'T have it, I wouldn't worry too much about not having VHF NAV capability.

Well hot diggity dog, thanks for providing that reference. Care to ask the DPE about the non-precision requirements that Bob pointed out?

Two comments
1. Yes IMHO the SL30 is the best nav ever built. e.g., I can shoot the KSCK LOC 29R with no other nav equipment working. My GRT HX will show the LOC course on the main CDI needle, and the VOR cross fix as an RMI pointer - with both nav signals coming from the SL30. I know of no other nav that can do that. Too bad they’re no longer made.
2. The issue with a gps-only airplane on the practical test is not the precision (or LPV in lieu of) approach. It’s the two non-precision approaches, ‘…each using a different nav aid’. The ACS then lists vor, loc, sdf, gps,…as examples. Problem is gps is only one type. What’s number two?

Aaaaand we are back at square one. Thanks Bob for pointing that out. Here are the quotes you reference if anyone wants to read it.

Task A. Nonprecision Approach
The evaluator will select nonprecision approaches representative of the type that the applicant is likely to use. The
choices must use at least two different types of navigational aids.

Examples of acceptable nonprecision approaches include: VOR, VOR/DME, LOC procedures on an ILS, LDA,
RNAV (RNP) or RNAV (GPS) to LNAV, LNAV/VNAV or LPV line of minima as long as the LPV DA is greater than
300 feet HAT. The equipment must be installed and the database must be current and qualified to fly GPS-based
approaches.
The applicant must accomplish at least two nonprecision approaches in simulated or actual weather conditions.
• One must include a procedure turn or, in the case of a GPS-based approach, a Terminal Arrival Area
(TAA) procedure.
• At least one must be flown without the use of autopilot and without the assistance of radar vectors. The
yaw damper and flight director are not considered parts of the autopilot for purposes of this Task.
• One is expected to be flown with reference to backup or partial panel instrumentation or navigation
display, depending on the aircraft’s instrument avionics configuration, representing the failure mode(s)
most realistic for the equipment used.
The evaluator has discretion to have the applicant perform a landing or a missed approach at the completion of
each non precision approach.​
 
Well hot diggity dog, thanks for providing that reference. Care to ask the DPE about the non-precision requirements that Bob pointed out?



Aaaaand we are back at square one. Thanks Bob for pointing that out. Here are the quotes you reference if anyone wants to read it.

Task A. Nonprecision Approach
The evaluator will select nonprecision approaches representative of the type that the applicant is likely to use. The
choices must use at least two different types of navigational aids.

Examples of acceptable nonprecision approaches include: VOR, VOR/DME, LOC procedures on an ILS, LDA,
RNAV (RNP) or RNAV (GPS) to LNAV, LNAV/VNAV or LPV line of minima as long as the LPV DA is greater than
300 feet HAT. The equipment must be installed and the database must be current and qualified to fly GPS-based
approaches.
The applicant must accomplish at least two nonprecision approaches in simulated or actual weather conditions.
• One must include a procedure turn or, in the case of a GPS-based approach, a Terminal Arrival Area
(TAA) procedure.
• At least one must be flown without the use of autopilot and without the assistance of radar vectors. The
yaw damper and flight director are not considered parts of the autopilot for purposes of this Task.
• One is expected to be flown with reference to backup or partial panel instrumentation or navigation
display, depending on the aircraft’s instrument avionics configuration, representing the failure mode(s)
most realistic for the equipment used.
The evaluator has discretion to have the applicant perform a landing or a missed approach at the completion of
each non precision approach.​

****, I was staring right at that bit.

Yeah - I'm waiting for an answer from the DPE and I'll let you know what he says.

<shrug> I've spoken with DPEs about this in the past and none of them said it was an issue but getting a current take on it makes sense.

EDIT - I'm guessing the "fig leaf" used in the past was considering WaaS vs. non-WaaS as different NAVAIDS. Given that that makes the difference in both the en-route and alternate filing rules, I'm expecting that's the justification used in the past...
 
So this is interesting....I actually took it to two DPEs. One responded, one has not yet.

The one I did speak to indicated that, in his opinion, the language "...representative of the type that the applicant is likely to use." can work in opposition to "non precision from different nav aids."

He punted to the FSDO. :)

<shrug> It may be the case where, as mentioned upthread, even if you can sub an LPV approach for an ILS, you might need a second airplane for one of the others, assuming your airplane doesn't have VHF. May be, ultimately, cheaper to do it that way.

I've already got NAV so I never delved this deeply into it before.
 
Before I wrote this reply, I also ran this by a DPE who is both significantly experienced an an RV owner. He would have no problem with administering a checkride that way.

I'm hoping to get my IFR rating before my plane is done, so in my case it's less about the checkride and more about safety and currency. Am I correct that currency regs aren't specific about what of approaches are needed (61.57c)?
 
Second responded:

"My POI says 2 NAVAIDS required. IE - one ground based, one satellite based. The combo of NP and P doesn't matter."


So there ya go. You do have to have at least one of those for the checkride.



EDIT - I really, really need to do more homework with respect to EAB. Still learning. This was educational for me.
 
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Thank you everyone for your input. You have all given me good things to think about.

If you’re just traveling for the fun of it, and occasionally needing to file IFR and light IMC with high personal minimums, then GPS only is likely acceptable.

This is simply one opinion. You should continue your due diligence and think about how you are really going to operate your airplane. What your personal comfort level is.

How you view small plane IMC flying seems very much in line with how I see it. I would do it in a pinch, say to get into or out of an airport on a fairly VMC day, but my mission would not necessitate low minimums or hours in clouds. In those conditions, I'd rather drive, fly commercial, or stay home. I also do not have ambitions for going beyond private pilot.
 
A couple of things to consider about GPS...

Ground interference to GPS isn't hypothetical; it occurs every day, sometimes without warning. The trucker-with-a-jammer scenario actually happened at the Newark airport and caused the FAA quite a few headaches as they tried to commission a ground-based GPS augmentation system for Cat 2/3 approaches right next to the intersection of two major interstate highways.

And sometimes the interference is intentional - check out this VAF thread- https://vansairforce.net/community/showthread.php?t=197329.

I've had a fair amount of experience since the early 90's with GPS in military and civilian applications and have been fortunate to work with people who are a lot smarter than I am about its operation. I won't put all my eggs in the GPS basket...not yet, at least :). I heartily concur with the recommendations here to find an inexpensive VOR/LOC receiver or maybe switch to a gently-used GNS-430W.

HTH

Dave
 
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Not to beat a dead horse - but I will anyway.

Over the last 10 months I’ve done a couple of dozen long, IFR cross countries (perhaps two hours total in IMC and no hard approaches). I fly with dual SkyViews and a GTN-650. I do NAV, LOC and ILS approaches for proficiency but have not done anything other than a RNAV approach for an actual IMC landing in years. Flying IFR (following the nice magenta GPS track) I still religiously tune in the next VOR along track. What I found over this period was about 4 out of 10 VORs shown on current charts are dead.

My point - the recent data has me leaning toward GPS only for the new project as I conclude the FAA is not maintaining the VOR system. I agree that ILS is a nice backup to RNAV, but for RNAV to go away such that a NAV/LOC/ILS approach is required the following things need to happen simultaneously:
- The GPS cloud goes down and is not coming back.
- I cannot get to an airport with VFR conditions using Dead Reckoning and/or vectors from ATC.
- ATC cannot provide assistance to help me land if below visual conditions.

That said, if I had a nice SL-30 I’d use it (best NAV/Comm ever made). Too bad Garmin killed it.

Now if Dynon came out with a SkyView EFIS based Nav/Comm similar to the current Dynon remote comm (that I put into three RVs), I’d be all over it.

Carl
 
GPS only v. GPS + NAV

Two separate questions:

1) What will I use 99% of the time?
2) What do I feel comfortable with?

The answer to (1) is GPS. Great stability on approach, both lateral and vertical, easy to create non-airway routes, etc... However, at least in the SW, there are FREQUENT NOTAMS about (possible) GPS outages--centered on the White Sands Missile Range, Yuma Proving Grounds, or other locations. Affected radii, even at 4K feet, can be large--400 nm. I flew from Tucson, AZ to Ames, IA the other day, with a fuel stop in the TX panhandle--mostly VFR, but needed to pick up a clearance for an approach. There were NOTAMS as mentioned above on that day. The system wasn't actually affected, but certainly could have created a challenge if it had been and GPS was the only option available to me. Even VFR, there is a lot of relatively featureless landscape along that route--as well as a few needles to be threaded to avoid Restricted Airspace. Sure, we've all done pilotage and ded reckoning, but how much of that have you done recently on long trips over terrain w/o much in the way of landmarks (especially if your sectional is an iPad screen, that now isn't geo-referenced). Doable, yes. Fun, not so much.

I don't disagree a bit that other b/u instrumentation is more important in terms of being able to keep the shiny side up, but there's no reason, except AMUs, that it has to be "or" rather than "and".
 
Second responded:

"My POI says 2 NAVAIDS required. IE - one ground based, one satellite based. The combo of NP and P doesn't matter."


So there ya go. You do have to have at least one of those for the checkride.



EDIT - I really, really need to do more homework with respect to EAB. Still learning. This was educational for me.

Bill, thanks a million for getting responses from two different DPEs!

Sorry OP for kind of hi-jacking but hopefully this helps you make the decision as well.
 
IMO, a GTN750xi is the best money you'll ever spend when it comes to panel mounted navigators. Go big or go home :D

i-dWN5CbH-XL.jpg
 
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I have seen the weather significantly lower than forecast. I have seen GPSs do really weird and unexpected things. Often simplicity and reliability is key. The ILS is pretty simple and reliable. NAV capability is something I wouldn't go without on an IFR capable airplane. Might not ever plan on using it. However, one day, it might be worth it's weight in gold. Consider a NAV radio like taking more than minimum fuel, probably not needed until it's really really important.

Granted most of us aren't professional pilots with 25,000hr careers and see multiple issues. How much are you willing to bet that you won't see one of those issues that the professional pilot has seen and is warning us about?
 
I have seen the weather significantly lower than forecast. I have seen GPSs do really weird and unexpected things. Often simplicity and reliability is key. The ILS is pretty simple and reliable. NAV capability is something I wouldn't go without on an IFR capable airplane. Might not ever plan on using it. However, one day, it might be worth it's weight in gold. Consider a NAV radio like taking more than minimum fuel, probably not needed until it's really really important.

Granted most of us aren't professional pilots with 25,000hr careers and see multiple issues. How much are you willing to bet that you won't see one of those issues that the professional pilot has seen and is warning us about?

I am nominating this for comment of the day.
 
This is a subject that I always find interesting and it will likely generate 3+ pages.

I just re-did my airplane’s entire avionics, electrical, and lighting. My airplane is very light IFR and has only a GNX375 for navigation / approach.

Just as a point of reference, to simply understand where I am coming from on my opinion. Opinion’s right? Please don’t take this as someone throwing their log book around because they think they’re an expert. I am not. That being said, I have a few hours in the book. Professional for 29 years, airline for 25 years, CFII/MEI for 29 years, 23K plus hours in the book, all civilian, and lots of time in bug smashers, but only about 1300 hours in single engine airplanes with about 200+ in RV6/8.

I personally look at flying IMC in RV’s like this; I can, if I have to, but I try to avoid it. Personal minimums are 1000/2. I want a fighting chance when I come out of the clouds with the engine stopped. Now, flying IFR? IE filing IFR to work in the system, flying to say an airport underneath a class B shelf to make the experience a little more efficient, mostly VMC? My ride will do the trick and I can always fall back to dead reckoning if everything goes south and I am down to the G5 and the ipad.

Lots of folks on this web page and YouTube have a far greater level of comfort in flying IMC. There will be hundreds of pages about the “impossible turn” and how it can’t or shouldn’t be tried, but little concern for hours in the soup. Approaches to minimums, IMC the entire flight with low ceilings below. Even icing. Building airplanes with double and triple redundancy. All the while sitting behind one engine, that when/if it quits, there isn’t a backup battery in the world that’s going to get you home that day. Not my cup of tea, but to each their own. I live around mountains and I am almost always flying over terrain that I may have a hard time successfully pulling off an off airport landing. My flying is not without risk. I fly my machine for fun. But I hope to get out and do some traveling soon and like to have the OPTION if I need it, but my personal RV IFR minimums are not flexible and I will always prefer VMC operations.

The depends part? I would commend anyone for getting an Instrument Rating. It is the best rating to improve your skill and knowledge. You will fly a more precise airplane and have a far better understanding of the system you’re working in. It’s THEE license to learn with. If, like Doug, you intend to use your airplane to move through ratings and gain experience, to possibly take up a second side career. Maybe getting a CFI to do some flying on the weekend on somebody else’s dime. Then I say yes! Outfit it with redundancy, IFR GPS and VOR/ILS at a minimum. Lots of ways to do that. From very expensive to reasonable as some have mentioned. If you’re just traveling for the fun of it, and occasionally needing to file IFR and light IMC with high personal minimums, then GPS only is likely acceptable.

This is simply one opinion. You should continue your due diligence and think about how you are really going to operate your airplane. What your personal comfort level is. As always, this should not be taken as a recommendation and your mileage may vary as they say.

I enjoyed reading about your experience and your educated opinion. Thank you. My father is a retired heavy driver with some interesting prior experience as well. Not surprisingly, his risk equation is similar to yours, and thus my own. It's nice to read a corroborating opinion so well explained. That said, GPS approaches were not a thing when my dad retired, and he marvels at the pink line approaches we have now. My airplane has a reasonably complete VOR/NAV/ILS suite as a result, and my dad regales me with tails of ADFs and NDBs regularly.
 
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No Nav

I trained and took my IFR check ride a few years back in my RV-7A. NO Nav on my plane just GPS. My DPE said Demonstrating that you could fly an LPV approach was as good as flying an ILS. So it depends on the DPE.
 
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• At least one must be flown without the use of autopilot and without the assistance of radar vectors. The
yaw damper and flight director are not considered parts of the autopilot for purposes of this Task.
.[/INDENT][/I]

This is interesting. WHen I took the checkride the rule stated that one aapr must be done with the AP. Looks like now the applicant can use AP for two of them. That makes things easier I suppose.
 
This is interesting. WHen I took the checkride the rule stated that one aapr must be done with the AP. Looks like now the applicant can use AP for two of them. That makes things easier I suppose.

Interesting. I think the new reg makes sense; if I have an autopilot I am going to use it most of the time. Makes sense to let a candidate use it more often than not. I wonder if it is up to the DPE or candidate to choose which one is done without it.
 
I personally look at flying IMC in RV’s like this; I can, if I have to, but I try to avoid it. Personal minimums are 1000/2. I want a fighting chance when I come out of the clouds with the engine stopped. Now, flying IFR? IE filing IFR to work in the system, flying to say an airport underneath a class B shelf to make the experience a little more efficient, mostly VMC? My ride will do the trick and I can always fall back to dead reckoning if everything goes south and I am down to the G5 and the ipad.


This is simply one opinion. You should continue your due diligence and think about how you are really going to operate your airplane. What your personal comfort level is. As always, this should not be taken as a recommendation and your mileage may vary as they say.

I have the exact same setup as Jason (GNX 375 only), and 100% agree with everything he says. To take it one step further, I make sure I have an alternate that is forecast to be VFR.

In my 35 years/15K hours of flying, I have only lost GPS signal couple of times, and only for a few seconds. I use the exact same personal minimums and am completely comfortable flying GPS only.
 
GPS only v. GPS + NAV

Two separate questions:

1) What will I use 99% of the time?
2) What do I feel comfortable with?

The answer to (1) is GPS. Great stability on approach, both lateral and vertical, easy to create non-airway routes, etc... However, at least in the SW, there are FREQUENT NOTAMS about (possible) GPS outages--centered on the White Sands Missile Range, Yuma Proving Grounds, or other locations. Affected radii, even at 4K feet, can be large--400 nm. I flew from Tucson, AZ to Ames, IA the other day, with a fuel stop in the TX panhandle--mostly VFR, but needed to pick up a clearance for an approach. There were NOTAMS as mentioned above on that day. The system wasn't actually affected, but certainly could have created a challenge if it had been and GPS was the only option available to me. Even VFR, there is a lot of relatively featureless landscape along that route--as well as a few needles to be threaded to avoid Restricted Airspace. Sure, we've all done pilotage and ded reckoning, but how much of that have you done recently on long trips over terrain w/o much in the way of landmarks (especially if your sectional is an iPad screen, that now isn't geo-referenced). Doable, yes. Fun, not so much.

I don't disagree a bit that other b/u instrumentation is more important in terms of being able to keep the shiny side up, but there's no reason, except AMUs, that it has to be "or" rather than "and".


Note to self, don't tempt fate by saying that even though there are NOTAMs, the system not actually affected all that often...

Flew home more or less via the reverse course today. Similar NOTAMs, but today the system WAS affected. Motoring along approaching El Paso after deviating a little east to avoid a convective SIGMET. Suddenly the GPS advises signal has been lost and it's in dead reckoning mode...suggest using an alternate navigation source if available. Queried ATC, wondering if it was me or the system. Sure enough, White Sands was jamming GPS from the El Paso area to near Tucson. We were VFR, but it would have been "interesting" if in IMC and there weren't a NAV as backup.
 
I'm not a radio guy, but the info I could find says GPS transmits 45 watts from 12,500 miles away and ILS is 25 watts for 15 nm minimum.

Inverse square... something... but again I'm no expert. Seems to me GPS is much weaker and susceptible to outages/interference. So I'm going with a terrestrial backup.
 
Getting back to the original question . . .

My question is: Are there any ILS/LOC approaches left that do not have a GPS overlay? Also, what about Europe and the rest of the world?
 
GPS Jamming is prevalent in the SW

Flew from Albuquerque to Las Cruces NM last week and just south of Albuquerque GPS and ADSB lost due to jamming from White Sands Missile Range. The next day, the same thing happened on the way back. No GPS, no ADSB. This is a regular occurrence and without a VOR some may wander into the restricted area.
 
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