A new panel with only GPS navigation for IFR flying

[Eric Pauley]

I don't see how someone who truly understands how brittle GPS is would tolerate a panel without backup nav. Personally, I want a monitored ground-nav approach at either my destination or alternate.

Civilian GPS can be (with difficulty) spoofed, and trivially blocked. Further, the "redundancy" offered by a backup GPS is a false sense of security because it's the system that lacks redundancy. Despite FAA rulemaking WAAS is not a backup. The attitude that leads to willingly giving up a reliable, proven, and free backup to such a fragile system is not consistent with safe IFR flying.

What's your plan if you're in the soup and lose GPS?

 

[Salty]

I don't see how someone who truly understands how brittle GPS is would tolerate a panel without backup nav. Personally, I want a monitored ground-nav approach at either my destination or alternate.

Civilian GPS can be (with difficulty) spoofed, and trivially blocked. Further, the "redundancy" offered by a backup GPS is a false sense of security because it's the system that lacks redundancy. Despite FAA rulemaking WAAS is not a backup. The attitude that leads to willingly giving up a reliable, proven, and free backup to such a fragile system is not consistent with safe IFR flying.

What's your plan if you're in the soup and lose GPS?

If you're planning on flying in IMC, I agree. Personally, I plan on VFR and IFR is my backup. Therefore, GPS is already the backup plan. I can't speak to the OP and if he is thinking a similar way.

 

[Steamflyer]

I fly a plane which is WAAS (GPS for this thread) only. It works fine, and have not had signal issues of either degradation or blocking of GPS signals. Might happen, but does seem rare. That aircraft flies about 100-120 hours a year and maybe shoots 10-15 approaches.

One minor consideration is that if the only precision approach capability is WAAS, the alternate minimum must be 800-2 (i.e. as if non-precision even though the alternate is very likely to have an LPV approach) as opposed to 600-2 if one has a second precision approach receiver (ILS).

No issue getting RNAV whilst they are advertising an ILS - they overlap anyhow. You will be given vectors, so know how to use VTF fluently in such a case. No flying a “T” at an airport using their ILS.

As far as fix/radial routing, GPS boxes in OBS mode treat the current waypoint, be it five or three letter, as a VOR. And since they all know every VOR, albeit as lat/long, you can fly any radial for any distance using a GPS receiver.

 

[Martin__]

That's a good question. I don't know the answer, but will ask the CFII. I suspect the best answer is to have a fully redundant GPS receiver/antenna combo, but will see.

In this scenario, you can tell ATC that the GPS failed and that you need radar vectors. Maybe followed by a PAR/ASR approach

 

[midlifeflyer]

No issue getting RNAV whilst they are advertising an ILS - they overlap anyhow. You will be given vectors, so know how to use VTF fluently in such a case. No flying a “T” at an airport using their ILS.

That’s changing. There are GPS-enhanced ILS approaches. Look for ILS Y & ILS Z. Might be a T configuration or just a TAA, but GPS is required. If there’s a T or other GPS NAV IAF you can get it. Even without the T, “direct to the IF” (which requires GPS) and cleared straight it is becoming more and more common because of the reduction of both pilot and controller workload.

 

[SebIp]

Feels liken there is a forgone conclusion so don’t get why post the question at all.

Also feel like there is a fair bit of making excuses in face of clear benefits. And somehow bit of resignation mixed in as well “oh well it’ll be too hard”. I mean if vor is too hard then partial panel is what? Doesn’t IFR requires practice like everything else?

Not sure what’s going to happen but feel like a bad thing brewing.

 

[dtuuri]

I do know how to use VORs...

So, you're willing to become proficient with the 200+ pages of operating instructions in order to use your GPS, but not willing to simply learn how to set up a VOR head that requires no manual, and that you already understand how to use? That makes no sense.

 

[MauleSkinner]

In this scenario, you can tell ATC that the GPS failed and that you need radar vectors. Maybe followed by a PAR/ASR approach

…assuming one of those approaches exists within a reasonable distance. Might just need a heading toward better weather until you run out of gas.

 

[WDD]

FWIW - I've not flown IFR using a VOR since my check ride. I've never flown a Victor highway. I see the VOR and Nav radio as an emergency back up.

And I'd never design a panel without at least one Nav radio.

- Spending time on VOR proficiency?
It's easy. Tune the frequency, spin the dial, and done. Follow the radial on the CDI. No different than following the CDI when it's getting the signal from GPS. In some sense, the only proficiency you need to add is 1) how to tune the radio, and 2) how to spin that dial thing on the CDI. And you're done.

- GPS will never go out?
Was flying a GPS approach in patchy weather, approaching the Final Fix, and yep - GPS just fuztz out. Held course via compass and thought of what to do. Call tower, tell them Pan Pan, can't go to GPS hold, switch to Approach, request to head to nearest VOR tower, head there, and then figure it out. Luckily the GPS came back before I had to do any of that as well I hit VMC, so continued approach.

Nutshell - easy and cheap enough to have a Nav radio. I'd add it. And I'm the biggest magenta line, its all about being proficient on the GPS navigator and your tablet, etc. guy you'll run into.

 

[Brad W]

How prevalent is PAR these days? Enough to be considered an emergency back-up?

 

[WDD]

How prevalent is PAR these days? Enough to be considered an emergency back-up?

Hardly none. A quick Google look up shows about 100 nationwide, and most of those are military. So no, I wouldn't count on a PAR as a practical back up, let alone as a primary back up to a GPS failure.

 

[Larry in TN]

In this scenario, you can tell ATC that the GPS failed and that you need radar vectors. Maybe followed by a PAR/ASR approach

That assumes you are in a RADAR environment. I believe the OP is the Pacific Northwest. Lots of mountains and airports with approaches that aren't covered by RADAR.

What I was trying to bring up earlier is that, with a GPS-only airplane, you'd have to consider those possibilities which might mean limiting yourself to VMC-only below radar coverage. To me, that's a pretty big limitation and can be removed by having a single VOR/ILS receiver on one of your GPS/COM radios.

 

[Lndwarrior]

Sorry I did not explain the motivation behind this thread (it was not the point).
In my estimate, I will fly 1-4 hrs in light IMC (think a few clouds or a thin cloud layer around an airport) per year (yes, year). Given my busy life, I would not be a safe pilot if I tried to maintain proficiency with VOR, LOC, ILS, and GPS navigation/approaches. That is why I have not gotten IR.
However, if I can obtain and maintain IR with just GPS, then I can maintain my proficiency and fly safely.
Since none of my trips are mandatory (I can cancel/change any time), I will cancel if there is a GPS outage, so not concerned about that at all.

The idea of just being good enough, or capable enough, for "light VMC" is a concept that will likely get you and a whatever poor sucker that's in the plane with you at the time, killed. Either you and your plane are competent and current for hard IFR, or you should stick to VFR.

Seriously, you should reconsider your attitude about IFR flight, because now it is dead wrong. Or at the very least fly solo so you don't take some innocent victim with you.

 

[Martin__]

How prevalent is PAR these days? Enough to be considered an emergency back-up?

No idea but it sounds like ASR approaches are more common

 

[Lndwarrior]

Feels liken there is a forgone conclusion so don’t get why post the question at all.

Also feel like there is a fair bit of making excuses in face of clear benefits. And somehow bit of resignation mixed in as well “oh well it’ll be too hard”. I mean if vor is too hard then partial panel is what? Doesn’t IFR requires practice like everything else?

Not sure what’s going to happen but feel like a bad thing brewing.

I have exactly the same feeling...

 

[WDD]

Mountain Dude: Here is another data point for your consideration; I just got this email from our club’s president. Keep in mind this refers to my home airport KRYY under the Bravo shelf here in Atlanta. If it can happen in the world’s busiest airport Bravo, it can happen anywhere.

Xxxxxxxxxxxxxxxxxxxxxx

The airport has received a handful of reports over the past few months regarding intermittent, brief GPS interference. Most reports stated there was a loss of GPS signal on the north ramp between the FBO and Alpha run-up pad. A few reports stated that pilots experienced a loss of GPS signal while on final for Runway 27. If you have noticed any pattern of this interference, email a Board Member your report and we will make sure it gets to Wes McDonald.

 

[luvflyin]

Hardly none. A quick Google look up shows about 100 nationwide, and most of those are military. So no, I wouldn't count on a PAR as a practical back up, let alone as a primary back up to a GPS

I found a list with 104 airports with Radar Approaches. 48 with PAR.

 

[WDD]

I found a list with 104 airports with Radar Approaches. 48 with PAR.

Copy that - more to the point of PAR not being a good reason to not have a Nav radio.

 

[Brad W]

Yeah, I've been out of the system for a while and had no idea..... Was just trying to think of back-up solutions for the system that maybe be cheaper and easier than maintaining a vast network of big ol' outdated VOR/DME stations.

I still contend that they should build a network of very low-powered NDB's placed at every major airport. No doubt ADF's could be produced small, lightweight, and cheap with today's technology. Seems like it could be simple, effective, and relatively cheap!

 

[Larry in TN]

Yeah, I've been out of the system for a while and had no idea..... Was just trying to think of back-up solutions for the system that maybe be cheaper and easier than maintaining a vast network of big ol' outdated VOR/DME stations.

The airspace system is not primarily designed around the needs of GA airplanes. The VOR/DME network is needed to provide back FMS updating via DME/DME/IRU. That allows them to continue flying enroute and terminal RNAV during a GPS outage. A network of low-power NDBs would not due the same thing.

 

[Brad W]

The airspace system is not primarily designed around the needs of GA airplanes. The VOR/DME network is needed to provide back FMS updating via DME/DME/IRU. That allows them to continue flying enroute and terminal RNAV during a GPS outage. A network of low-power NDBs would not due the same thing.

good point....a paradigm shift there....

 

[luvflyin]

Copy that - more to the point of PAR not being a good reason to not have a Nav radio.

Yeah. If you knew there were suitable ones along your route of flight maybe factor it in. And then pray your radio doesn’t go nips up if you need a Radar Approach to get down.

 

[WDD]

The airspace system is not primarily designed around the needs of GA airplanes. The VOR/DME network is needed to provide back FMS updating via DME/DME/IRU. That allows them to continue flying enroute and terminal RNAV during a GPS outage. A network of low-power NDBs would not due the same thing.

I’d think it would be relatively cheap to place back up ground based GPS emitters close to key airports. A mini array of GPS “ground based” satellites if you will.

 

[asicer]

I still contend that they should build a network of very low-powered NDB's placed at every major airport. No doubt ADF's could be produced small, lightweight, and cheap with today's technology. Seems like it could be simple, effective, and relatively cheap!

The receiver could probably be small/light/cheap but I'm not so sure about the antennae.

 

[dtuuri]

I still contend that they should build a network of very low-powered NDB's placed at every major airport.

I've wondered why ADFs can't use AM broadcast stations and triangulate position based on known station locations the way GPS triangulates from satellites.

 

[MackMooney]

how about putting a beacon on top of all the cell towers, functioning sim to gps. or hurry up and turn ELoran back on

 

[Pinecone]

Maybe followed by a PAR/ASR approach

Are there any civilian airport only PARs?

I may have ask for an ASR my next flight to see what the controller says.

 

[Steamflyer]

Are there any civilian airport only PARs?

I may have ask for an ASR my next flight to see what the controller says.

While flying last week a pilot asked for an ASR. Controller informed them no one trained on the procedure at that time. So unable even though listed.

 

[Martin__]

While flying last week a pilot asked for an ASR. Controller informed them no one trained on the procedure at that time. So unable even though listed.

I think they have to be current like IR pilots have to.

Plan B for OP could perhaps be to get vectored and brought down to MVA for a visual approach.

With that said, I don’t mind OP’s risk/reward philosophy as he sees it. Freedom to chose for himself I guess.

 

[Pinecone]

While flying last week a pilot asked for an ASR. Controller informed them no one trained on the procedure at that time. So unable even though listed.

That is what I expected.

Personally, I would rather look back on my flying career and say, yeap, some of them were right, I never needed that VOC/LOC installed in my plane versus being flying on a dark and stormy night with a GPS outage saying, WOW, I REALLY wish I had a VOC/LOC receiver.

 

[Salty]

I’d think it would be relatively cheap to place back up ground based GPS emitters close to key airports. A mini array of GPS “ground based” satellites if you will.

I think that was called LORAN.

 

[luvflyin]

I’d think it would be relatively cheap to place back up ground based GPS emitters close to key airports. A mini array of GPS “ground based” satellites if you will.

Like LORAN was

 

[Pinecone]

I think that was called LORAN.

Not exactly. LORAN was a few stations far apart.

Easier to do DME-DME nav. DME is easy to put up and doesn't need much real estate

 

[Av8r_Sed]

I've read this thread with interest as I'm planning an IFR panel for a new Kitfox build. My initial tendency was too to go with GPS only.

Last evening I watched a FAASTeam webinar presented by Gary “GPS” (Guy in Pink Shirt) Reeves "Garmin GPS175 GNC355 GNX 375 Getting Started". At 13:10 he starts a segment on GPS outages including jamming and spoofing and he makes a strong case to maintain VHF Nav capability, even if it's provided by only a handheld radio.

Garmin GPS175 GNC355 GNX 375 Getting Started

 

[MountainDude]

I've read this thread with interest as I'm planning an IFR panel for a new Kitfox build. My initial tendency was too to go with GPS only.

Last evening I watched a FAASTeam webinar presented by Gary “GPS” (Guy in Pink Shirt) Reeves "Garmin GPS175 GNC355 GNX 375 Getting Started". At 13:10 he starts a segment on GPS outages including jamming and spoofing and he makes a strong case to maintain VHF Nav capability, even if it's provided by only a handheld radio.

Garmin GPS175 GNC355 GNX 375 Getting Started

I think that makes sense for those planning to fly IFR frequently. However, if you spend a total of 1-4 hrs per year in IMC, the odds of GPS suddenly going down are extraordinarily small.

 

[MauleSkinner]

I think that makes sense for those planning to fly IFR frequently. However, if you spend a total of 1-4 hrs per year in IMC, the odds of GPS suddenly going down are extraordinarily small.

Smaller than the odds of an engine coming apart the day after the A.D. comes out limiting the failed part to 4 more flights, and I’m taking off on a 4-leg trip?

I’d rather have a plan for the eventuality than play the odds. I must be part Russian…

 

[Tools]

I understand it’ll cost more, but I REALLY REALLY like the Dynon setup. If I were going HARD IFR capable I’d probably want all Garmin. But for what you’re doing I’d actually prefer the Dynon setup.

The integrated functionality of the radios, autopilot, transponder and ADSB stuff (think weather, especially for vfr) is super nice. Also having so much airspace and airport info at your fingertips….

This frees up your iPad so you can watch the Great Waldo Pepper on a x/c.

 

[YakDrvr]

I understand it’ll cost more, but I REALLY REALLY like the Dynon setup. If I were going HARD IFR capable I’d probably want all Garmin. But for what you’re doing I’d actually prefer the Dynon setup.

The integrated functionality of the radios, autopilot, transponder and ADSB stuff (think weather, especially for vfr) is super nice. Also having so much airspace and airport info at your fingertips….

This frees up your iPad so you can watch the Great Waldo Pepper on a x/c.

A Dynon HDX (with VFR GPS, ADS-B in/out, & VHF radio) combined with an IFD440 is a relatively simple way to get “hard” IFR capability. Being able to put the approach plate on the PFD with own ship displayed, while you shoot the approach makes life very easy. The VHF NAV gives you VOR/ILS functionality and you don’t need a ton of panel space. Additionally, you can link the IFD440 to the IFD100 app on your iPad for another big display or stick the iPad in your flight bag since you have no need for it.

 

[Papa Pilot]

FWIW
I spent a couple of years incrementally upgrading my panel before doing my IR training. From the very get go I settled on a separate space based navigation system and a separate ground based navigation system. Ended up with a GPS only unit, a COM, a NAV/COM and DME.

Very happy with the setup. During IR training I was exposed to and practiced several types of GPS and ground based approaches. (After all, I'd have to prove to the examiner I could use everything.)

I feel I am a better pilot for having learned the many different types of approaches.

 

[Arnold]

The FAA is maintaining the VOR MON (Minimum Operational Network) as a basically foolproof back up to GPS. See: https://www.faa.gov/about/office_or...rvice_units/techops/navservices/gbng/vormonIs retiring your VHF equipment premature? Some things to consider. GPS satellite output is 50W. VOR is (IRC) 1000W.

My European and Asian clients are reporting significant areas of GPS Spoofing. So far it has been quite obvious to the human observer (pilot). But the box does not know if the signal is spoofed or real and assumes all signals are real. The pilot must recognize the spoofing and select an alternate method of nav. This means deselecting GPS and allowing the FMS to default down to DME/DME or DME/DME/IRU.

If I were navigating in low IFR with just GPS I would want to know where is the nearest a) good weather (not actually particularly "good" in my book. Ceiling not below the MSA or MVA if known and at least 1 mile vis. But my plane goes very slow), b) PAR approach.