Is adding vor worth it?

[RussR]

I hope you mean ded reckoning, not pilotage. 20 miles by pilotage should be rather simple.

I was over eastern Colorado at fairly low altitude a couple times over the past few weeks. I commented to the other pilot that it would be really easy to get lost out there, what with a pretty sparse amount of any kind of visual checkpoints. Really flat, and everything looks the same. However, somehow I did it years ago, as my Private solo XC flights were in that same area, pre-GPS. Our "lost" procedures, as explained by my instructor, were "if you get lost, just turn west and fly until you see Pike's Peak. Then you should be able to find your way home."

 

[RussR]

The risk of GPS unavailability is overblown. If you understand how GPS jamming works, you realize the chance of being stranded or losing guidance in the air is wildly remote.
....
The problem was on your end. It is not physically possible to jam such a large area. Or maybe there was a WAAS issue. But that just degrades accuracy to 10 meters, plenty accurate for navigation.

I'm not sure what you're getting at. Are you saying that @unsafervguy and the other airliners reporting outages were all coincidentally suffering the same type of equipment failure at the same time? Or, in my situation, the 50 nm of GPS outage that was reported by numerous airplanes, was all an example of, again, simultaneous failure of (presumably) multiple different types of receivers? GPS interference, whether intentional or not, does happen, and it is well documented.

How about the GPS interference that went on last October in the DFW area, affecting the usability of STARS into the area? It was a pretty big deal, reported in the national media. (Previous thread: https://www.pilotsofamerica.com/community/threads/gps-interference-at-dallas.140278/ )

 

[asicer]

And I've flown long XC with nothing but a whiskey compass, stopwatch, and paper charts.

But it sucks.

My first thought when I read that was "I ought to do that in the near future". Just goes to show that one person's "sucks" is another's "fun".

 

[asicer]

The initial plan is to use an Ipad and a stratux just like I do in rentals. BUt I wouldn't mind a slightly updated panel in the future just in case I put myself in a situation where I need more than an AI and DG.

Swap out the KY197 that's sitting above the transponder for a Garmin SL30 or a Trig TX56a. Both are the same size as the King and both have built-in CDI so no need to mount a new one. Should be good enough for your stated purpose as well as provide a base for future IFR upgrade.

 

[ateamer]

GPS interference/outage NOTAMs were pretty routine when I lived in California, often centered on China Lake. They start at 150+NM diameter at ground level and go up from there to 500+NM at high altitudes. Not a frequent occurrence here in Florids, but there occasionally is one.

 

[Ed Haywood]

I'm not sure what you're getting at. Are you saying that @unsafervguy and the other airliners reporting outages were all coincidentally suffering the same type of equipment failure at the same time? Or, in my situation, the 50 nm of GPS outage that was reported by numerous airplanes, was all an example of, again, simultaneous failure of (presumably) multiple different types of receivers? GPS interference, whether intentional or not, does happen, and it is well documented.

How about the GPS interference that went on last October in the DFW area, affecting the usability of STARS into the area? It was a pretty big deal, reported in the national media. (Previous thread: https://www.pilotsofamerica.com/community/threads/gps-interference-at-dallas.140278/ )

What I am saying is that degradation and interference is not the same as an outage, and that the scenario of being in the air and unable to get navigation guidance for successful completion of an IFR flight is wildly unlikely. Therefore the premise that you need a VOR in case you lose GPS is false. If that were really the case, the FAA would mandate VOR capability for IFR certified aircraft, which they do not.

I think many anecdotal reports by pilots are due to lack of understanding of their equipment and the underlying technology. They get warning messages letting them know that their reception of ground-based WAAS is degraded, which can happen for numerous reasons, and they misinterpret minor degradation as an "outage". In reality they still have non-WAAS satellite GPS location, which is accurate to 10-15 meters, and perfectly adequate for en-route guidance.

As an example, in the previous thread you linked to, there is a map of a "really big" incident last fall. I'll bet not many people looked at the legend. The yellow-shaded area shows 2-10% interference. That still leaves >90% signal reception.



Further, there is a difference between highly localized interference and a broad area outage. Civilian spoofers are readily available and often used for purposes as mundane as commercial drivers lying to their bosses. But those devices only have a range of a few hundred meters at most, and cannot cause a broad area outage. A GA aircraft would only be affected for a few seconds However, if one of those devices is placed directly under final approach to a busy airport, of course it can cause problems. However, those problems are highly localized and easy to work around. For example, on the DFW outage in the thread you posted, one runway was affected, but the other runways on the same airport remained open.

GPS outages are taking on the attributes of many other internet theories. People are taking a limited number of isolated events and conflating them to something bigger than reality.

 

[Ed Haywood]

My first thought when I read that was "I ought to do that in the near future". Just goes to show that one person's "sucks" is another's "fun".

I agree. I was just responding to a high hanging curve.

 

[RussR]

What I am saying is that degradation and interference is not the same as an outage, and that the scenario of being in the air and unable to get navigation guidance for successful completion of an IFR flight is wildly unlikely. Therefore the premise that you need a VOR in case you lose GPS is false. If that were really the case, the FAA would mandate VOR capability for IFR certified aircraft, which they do not.

Maybe I'm dense, but I'm still not getting your point. Call it interference, denial, outage, solar flares, equipment failure, whatever, if the effect is that the GPS in the plane says "GPS NAV LOST" or some similar alert, then the effect is the same and the reason for it is irrelevant to the pilot - I need a backup. In my example case, the G1000 lost all GPS navigation ability, NOT just WAAS, went into "DR" mode and I flew on that for 50 miles or so. Since it was clear VMC at the time, my "backup" was my eyeballs. But had I been in IMC and had the GPS signal not come back before my destination, I would have needed a VOR or ILS approach to get down. Fortunately the airplane I was in had that equipment. If it did not, I would have been in a more challenging scenario.

You do not NEED a VOR/ILS as a backup to GPS. You can roll the dice and take your chances, and you'll probably be okay. But it's a really good idea.

 

[chemgeek]

VFR: a basic NAV/COM and CDI, paired with a portable GPS or GPS-capable tablet/EFB should have you covered for any circumstance.
IFR: a GPS/NAV/COM will do it all. You could go cheaper with a GPS/COM, but in the rare event of an unplanned in-flight GPS outage, you could be in a pickle for a needed approach.

The reality is that since installing a GNS-430W decades ago, I have not used VOR navigation, ever, except for demonstrating ability during IPCs or flight reviews. I have flown some ILS procedures, but could have opted for a GPS approach if desired. I kept my previous NAV/COM unit as a backup, but it doesn't get used much except for talking to ground or clearance. on the COM side, and verifying NAV1 function during and ILS approach. But it really didn't cost anything to keep it in the panel.

 

[Ed Haywood]

Maybe I'm dense, but I'm still not getting your point. Call it interference, denial, outage, solar flares, equipment failure, whatever, if the effect is that the GPS in the plane says "GPS NAV LOST" or some similar alert, then the effect is the same and the reason for it is irrelevant to the pilot - I need a backup. In my example case, the G1000 lost all GPS navigation ability, NOT just WAAS, went into "DR" mode and I flew on that for 50 miles or so. Since it was clear VMC at the time, my "backup" was my eyeballs. But had I been in IMC and had the GPS signal not come back before my destination, I would have needed a VOR or ILS approach to get down. Fortunately the airplane I was in had that equipment. If it did not, I would have been in a more challenging scenario.

Because your story presupposes that the cause was external to your equipment, and therefore is proof that the GPS system cannot be relied upon. If the fault was with your equipment, then that increases your backup options to include other GPS devices, including portables, tablets, smartphones, etc. All more affordable than installing a VOR.

Did you have other GPS capable devices on board? Did they lose signal too?
Did you check the GPS status page on your G1000? How many satellites were you receiving? What was your current GPS solution? Was there a discrepancy between GPS1 and GPS2?



If your argument is that you need a backup nav device, yeah absolutely. I typically fly with 3 GPS devices, and I'm VFR only. My issue is with using anecdotes of uncertain cause (like yours) to extrapolate that the GPS system is subject to unpredictable outages. Like shark attacks, I think the incidence of unannounced outages seems more than it actually is.

 

[RussR]

Because your story presupposes that the cause was external to your equipment, and therefore is proof that the GPS system cannot be relied upon.

I'm not sure how to interpret the outage/interference/etc. any other way. Because if the failure was in my equipment, then it sure was coincidental how the several other aircraft that reported outages to ATC at the same time in the same area all must have had the same equipment failure that I did.

I'm not sure you're reading these parts of my posts:

Other aircraft were reporting it too.

Or, in my situation, the 50 nm of GPS outage that was reported by numerous airplanes

I'm not sure why you seem so unbelieving of the fact that the GPS outages/interference/etc. DO happen. Just in this thread we have @unsafervguy 's experience, mine, the DFW interference case in October, the NJ truck driver jamming case, and even GPS outage NOTAMs on a regular basis in (mostly) the western U.S. that warn about GPS unreliability for hundreds of miles. And yet you keep claiming that GPS problems affecting multiple users are exceedingly rare. Maybe you've never seen them in central FL, and I'm not saying they are "common", but they are certainly common enough that pilots should be prepared for them and discuss/train as part of an IPC on how to deal with them.

I count 13 NOTAMs effective later this week for GPS, "including WAAS may not be available" for what appears to be two outages but affecting Ft Worth, Houston, Albuquerque, Memphis, and Atlanta ARTCC's airspaces. The NOTAMs have them centered approximately on Fort Polk, LA, and somewhere near the Big Bend part of TX.

 

[Ed Haywood]

I'm not sure how to interpret the outage/interference/etc. any other way.

I'll ask again: did you check the GPS Status Page on your G1000? What did it say?

I'm not sure why you seem so unbelieving of the fact that the GPS outages/interference/etc. DO happen. Just in this thread we have @unsafervguy 's experience, mine, the DFW interference case in October, the NJ truck driver jamming case, and even GPS outage NOTAMs on a regular basis in (mostly) the western U.S. that warn about GPS unreliability for hundreds of miles.

Because you are conflating several very different events with unrelated technical causes into one big common thing, which they are not.

 

[camorton]

But I’m thinking step 1 would be a comm/nav unit with a vor/ils indicator but question if it’s already obsolete.

I think you have your answer here. For VFR flying, a VOR/ILS receiver is not needed - a complete waste of money. For occasional IFR flying, a GPS receiver alone will get you into 99.5% of airports in the US. The Garmin 175 is the cheapest example I'm aware of. For frequent IFR flying, an old-school NAV (and second COM) are important backups. For instrument training, it's way cheaper to rent a plane than to install equipment you will never use after the checkride.

C.

 

[WDD]

I would get a GNX 375. Get ADBS in and out as well as GPS navigation capabilities. Skip the Nav radio. When you want to do IFR, you can add a CDI in the center column, or a round 275 to replace your DG to preserve the original look.

(And..... please have them re arrange your six pack to the classic order).

 

[Albany Tom]

I think it would be cool if someone made an INS backup for GPS. It shouldn't be all that difficult, with micro-gyros and accelerometers. Pretty sure A-5's had INS in the 70's? It could get the initial position and speed from GPS, the emulate GPS output NEMA codes if GPS were lost. There would be some drift, but a lot less than a person trying to do ded reckoning.

For any of you EE students out there, this would be a great project! Please make it open source. Thank you.

 

[Will Kumley]

I would get a GNX 375. Get ADBS in and out as well as GPS navigation capabilities. Skip the Nav radio. When you want to do IFR, you can add a CDI in the center column, or a round 275 to replace your DG to preserve the original look.

(And..... please have them re arrange your six pack to the classic order).

LOL, I actually think this is the classic look for this planes panel. Its a Piper Colt and the owners manual even shows the instruments in the same locations. Although, I agree, rearranging them would make it easier to look at.

 

[mondtster]

(And..... please have them re arrange your six pack to the classic order).

They may be arranged the way they are due to clearance problems behind the panel. It's a problem on many older aircraft. The shallower electronic instruments like the 275 can help allow some rearrangement if that is a desire.

 

[WDD]

A Piper Colt with six 275s!

 

[Tantalum]

in the event of a gps outage

I've had GPS go out more than once flying around Southern California, different planes too, everything from 430 to 750. The outage is momentary but enough to give you pause. I like having the VORs dialed in (or the ILS if on RNAV and there's an ILS available) as an extra safety blanket

Flying out to IFP the other night over the dark moonless desert having the VOR point towards EED to agree with the GPS was good piece of mind!

 

[a572mike]

Personally, I'll always have a VOR Radio in a cross country airplane. There are some AWOS's out there (especially in the People's Republic of Minnesota) that broadcast on the VOR frequency, and some RCO's that require you to tune to the VOR to listen to Flight Service (e.g. the Bonneville and Toadstool VOR's).

 

[elvisAteMySandwich]

Speaking of GPS interference, the eastern seaboard will be seeing a couple GPS interference tests over the next several weeks.

• Fort Bragg, NC - https://www.faasafety.gov/files/notices/2023/Apr/FTBRNC_23-27_GPS_Flight_Advisory_(Revision_1).pdf
  
• Patuxent River, MD - https://www.faasafety.gov/files/notices/2023/Apr/PAXRVR_23-01_GPS_Flight_Advisory.pdf

 

[Mongoose Aviator]

Speaking of GPS interference, the eastern seaboard will be seeing a couple GPS interference tests over the next several weeks.

Pilots are encouraged to report anomalies in accordance with the Aeronautical Information Manual (AIM) paragraphs 1-1-13 and 5-3-3.

Has anybody knowingly flown through one of these GPS Interference Tests? I am wondering what does a WAAS gps show? I am considering to check out the Fort Bragg event myself to see what it does. Just curious.

My personal experience with gps outage is limited to one XC night flight where my gps antenna went bad. At the time, we did not know it was the antenna only that we started having gps problems. Even then, we still had a VOR receiver for backup nav. After upgrades, the aircraft now has multiple redundancies for navigation.

I subscribed to this site for email forecasts that may impact gps navigation from the sun.
https://www.spaceweather.gov/

I just saw this website. Looks interesting.
https://gpsjam.org/

Appears to also have historical information available.
https://gpsjam.org/?lat=32.22910&lon=-97.58091&z=5.0&date=2022-10-18

ATCSCC ADVZY 069 D10/ZFW 10/17/2022 D10 GPS ANOMALIES
MESSAGE:

EVENT TIME: 17/2115 - 17/2359
CONSTRAINED FACILITIES: ZFW
D10 IS EXPERIENCING GPS ANOMOLIES THAT ARE DRAMATICALLY IMPACTING
GPS (RNAV) ARRIVALS AND GPS SID DEPARTURE ROUTES FOR ALL AIRPORTS IN
D10 AIRSPACE, TO INCLUDE DFW, AFW, DAL, FTW, DTO, TKI, RBD, GPN,
NFW, GKY, AND ADS.

IF YOU ARE FILING INTO ONE OF THESE AIRPORTS PLEASE FILE THE
CONVENTIONAL ARRIVALS. ZFW/D10 ARE RELYING ON THE USE OF OLDER
GROUND NAVAID BASED ARRIVALS AND RADAR VECTORS.

THIS WAS UNPLANNED AND THE CAUSE IS YET UNKNOWN. THE LENGTH OF THIS
OUTAGE IS THEREFORE UNPREDICTABLE AND WILL REMAIN IN EFFECT UNTIL
FURTHER ADVISED.

SPECIAL NOTE FOR DFW ARRIVALS:
1) ZFW UNDERSTANDS THAT THERE IS NO LONGER A NON RNAV ARRIVAL INTO
DFW FROM THE SOUTHWEST CORNER FIX. THEY SAID USERS SHOULD FILE THE
ARRIVAL COMING IN FROM THE SOUTHWEST AND EXPECT RADAR VECTORS. THAT
WAY IF THEY GPS STARTS WORKING THE FLIGHT PLAN HAS THE CORRECT
ARRIVAL.
2) RY 35R IS UNUSABLE AT THIS TIME DUE TO THE GPS ANOMOLIES


EFFECTIVE TIME:

172151 - 180030
SIGNATURE:

22/10/17 21:51

 

[Will Kumley]

Reviving this thread to see if opinions have changed or not. I'm also adding an updated photo of my panel.

Goal: Currently using the Colt for IFR training in SoCal, the typical IFR flying out of my home airport of KOXR is punching through a marine layer, but rarely do we have thick IFR conditions. Once IFR training is complete I plan to stay proficient using primarily the 375 paired to the aspen panel so it's all GPS, if I add a nav/com I'll obviously use that as well to maintain proficiency as well as completing the required VOR checks every month.

Considerations for me:

Trig TY96A com unit. This would give me a com radio with a monitor function and built in intercom (Colt is only a 2 seat airplane). Install would be fairly simple and removes the existing intercom freeing up space for an older but working JPI EGT/CHT gauge that was gifted to me by a friend. Install for the unit would likely be a day after I build the harness. I might be okay with the idea of a handheld radio with vor capabilities as an emergency backup.

Trig TX56A nav/com. Same benefits as the com only unit and adds a vor/ils/gs receiver but comes at an additional cost. It also requires installing the Aspen ACU and another antenna. I'll also need to figure out the best way to add a VOR antenna to a fabric airplane. Best guess on install time for me is 3-4 days just because I'd be adding an antenna but it's not as simple as bolting the antenna to the plane.

FYI- I was an avionics tech in the Navy for quite some time and have a great A&P/IA that allows me to do the bulk of the work under his supervision which is a great benefit.

 

[Salty]

Here is a fresh thread with a lot of discussion on this topic: https://www.pilotsofamerica.com/community/threads/gps-backup.148081/

 

[TCABM]

…Once IFR training is complete I plan to stay proficient using primarily the 375 paired to the aspen panel so it's all GPS, if I add a nav/com…]

I encourage you to read the abnormal procedures section of the GNX375 AFMS. It starts on p.27.

https://static.garmin.com/pumac/190-02207-a3_04.pdf

 

[WDD]

It looks like you have one com and the GNX 375 GPS.

Skip the Nav radio.

Don’t listen to this guy. If you’re flying IFR add a back up Nav radio. Replace the com radio you have with a new Nav/Com unit and figure out someway to mount that VHF antenna.

I just bought a plane with GPS only, and after flying it, reading more posts here and noodling it over, yeah, I’m installing a Nav radio. Already sent the down payment and am on the calendar with the avionics shop.
………………………………
If you’re keeping this plane for a while, think about installing a PS PAR 200B audio panel with a built in com. You’ll have two coms, Bluetooth, all sorts of what not for small panel real estate.

But hey - easy enough for me to suggest how others spend money.

 

[asicer]

If you’re keeping this plane for a while, think about installing a PS PAR 200B audio panel

You know, I notice you keep mentioning the PAR200B in these avionics threads as if you are about to sell one soon.

 

[Will Kumley]

If you’re keeping this plane for a while, think about installing a PS PAR 200B audio panel with a built in com. You’ll have two coms, Bluetooth, all sorts of what not for small panel real estate.

I have yet to find a reason I need all of the additional functions/features of the PAR 200B. As my plane is a 2-place airplane I feel something like the Trig TX56A would cover all the bases. It provides a Nav/Com with the ability to monitor the standby frequencies. Has a built in 2 place intercom, aux audio input that I could use to hear alerts from both the Aspen PFD and Garmin GNX 375, and is able to operate off a single circuit breaker. It also takes up less space than the PAR200B would when you consider you still need a Nav radio and the Com radio is a remote unit that has to be mounted somewhere. The PAR200B is indeed a nice unit but the extra features I gain (bluetooth, 4 place intercom) are features I don't really need and it would ultimately take up more panel space than an all-in-one nav/com with integrated intercom. When we build the experimental airplane my wife is looking at, the PAR200B might be the best thing, but that's pretty far into the future.

 

[WDD]

Adding a second Com - Well you don’t need it but it would be nice. That’s part of suggesting to other people how to spend their money.

But to your question. Yes, get a nav/com to replace that com only radio - since you did ask.

 

[asicer]

Trig TX56A nav/com. Same benefits as the com only unit and adds a vor/ils/gs receiver but comes at an additional cost. It also requires installing the Aspen ACU and another antenna.

The TX56a has a digital interface for CDI. The Aspen can't understand it and needs an analog converter unit?

 

[Tom J]

That's correct, if the nav input isn't on a RS-232/ARINC429, it has to go through the ACU. The TX56 outputs the "old school" left/right/up/down on parallel lines.

 

[asicer]

That's correct, if the nav input isn't on a RS-232/ARINC429, it has to go through the ACU. The TX56 outputs the "old school" left/right/up/down on parallel lines.

Yes, but the TX56 also outputs "SERIAL CDI" over RS232 (supposedly).

 

[WDD]

Yeah - better call Aspen and ask them what Nav Coms will work with what you have. Garmin’s new Nav Com model, etc.

 

[WDD]

You know, I notice you keep mentioning the PAR200B in these avionics threads as if you are about to sell one soon.

Step right up! Sir, we’ve never met. Tell the crowd about Dr Pinrose amazing elixir!! Hurry hurry hurry before they are all gone!

I had actually never seen a Par200b before I got the plane. For someone with tight panel space, this is an impressive piece of equipment. It is good low cost option to add an audio panel and a second com, so I understand why the previous owners put it in. If the plane didn’t have a GNC 355 in it already that I’ll be using for a Com 2 I’d be keeping the PAR 200B. (I’m adding a GTN 650xi to give me Com 1 and a Nav)

 

[Will Kumley]

Yeah - better call Aspen and ask them what Nav Coms will work with what you have. Garmin’s new Nav Com model, etc.

I've got the Aspen install manual and communicated with them directly. The ACU is required for the Trig nav/com to connect to it. While not overly complicated, it adds cost to the project. Another option would be to install a more traditional nav indicator and skip connecting it to the Aspen, but it might be more expensive to go that route as I don't already have a nav indicator.

 

[WDD]

I've got the Aspen install manual and communicated with them directly. The ACU is required for the Trig nav/com to connect to it. While not overly complicated, it adds cost to the project. Another option would be to install a more traditional nav indicator and skip connecting it to the Aspen, but it might be more expensive to go that route as I don't already have a nav indicator.

Does the new Garmin or other options need an ACU? It would indeed be a shame not to connect the new Nav radio to your Aspen indicator.

 

[asicer]

I've got the Aspen install manual and communicated with them directly. The ACU is required for the Trig nav/com to connect to it. While not overly complicated, it adds cost to the project. Another option would be to install a more traditional nav indicator and skip connecting it to the Aspen, but it might be more expensive to go that route as I don't already have a nav indicator.

That's surprising. The Trig is supposed to be the same RS-232 protocol as the SL30. I wonder if you asked Trig whether they would give you a different answer.

 

[Will Kumley]

Does the new Garmin or other options need an ACU? It would indeed be a shame not to connect the new Nav radio to your Aspen indicator.

The new Garmin units wouldn't require the ACU, but they also don't have a built in intercom.

 

[Will Kumley]

That's surprising. The Trig is supposed to be the same RS-232 protocol as the SL30. I wonder if you asked Trig whether they would give you a different answer.

The SL-30 also requires the ACU according to the Aspen install manual. I asked Trig about connecting to the Aspen as well but haven't gotten an answer yet. But I looked at photos of other Trig/Aspen combos and they all appear to have the ACU in the picture as well.

 

[asicer]

The SL-30 also requires the ACU according to the Aspen install manual. I asked Trig about connecting to the Aspen as well but haven't gotten an answer yet. But I looked at photos of other Trig/Aspen combos and they all appear to have the ACU in the picture as well.

OK, so I dug out the Aspen install manual. Apparently they don't support the SL30's digital RS-232 protocol, which is a bit odd since it's pretty well documented.