Substituting non-IFR GPS for DME

[jsstevens]

I'm training for my IR in a C-172 which has a VFR only Garmin 100 GPS (hasn't had a current database made for it for several years) and a King VOR/LOC with glide slope. Today, for training, I flew DME arc approaches into KISM (VOR/DME-A) using the GPS (set to the ORL VOR) as a DME.

We were always VFR so we were legal, but would we be legal on a IFR flight? (IMC or not is, I think, immaterial). The instructor claims that since the GPS DOES have functioning RAIM, it's legal.

John

 

[James331]

I don't think so.

Look at the boot up screen, most of those things even say "not for IFR use" or "for situational awareness only"

 

[TheGolfPilot]

Could you? Yes. Is it legal? No.
In 1998 the FAA said you could use an IFR-certified GPS in lieu of DME.
A non certified gps is good for nothing more (actually less) than foreflight is. Situational awareness only.

I would file for /U and and fly approaches accordingly. Enroute, you can ask for dead reckoning or Vectors direct if you want to use that thing.

 

[Jim Rosenow]

I've been told by a couple different controllers (different facilities) that as long as you are on radar, they don't care what you use to navigate (we were IMC), including the GPS from your car (OK, I made the 'car GPS' part up). I have no FAR or other cite to back them up on it. Absent radar, no clue. YMMV!

Jim

 

[TheGolfPilot]

I've been told by a couple different controllers (different facilities) that as long as you are on radar, they don't care what you use to navigate (we were IMC), including the GPS from your car (OK, I made the 'car GPS' part up). I have no FAR or other cite to back them up on it. Absent radar, no clue. YMMV!

Jim

It is my understanding that ATC really doesn't care how you do anything. If you fly a GPS Y approach with your Ipad, they don't care. They only ask questions when you screw up, then the FAA gets involved, they find out you were doing things illegally and your slap on the wrist turns into a ticket pull faster than a reentry space shuttle and with way more heat.

 

[Jim Rosenow]

Like I said....I have no cite...merely anecdotal. You are most likely correct.

Jim

 

[MauleSkinner]

What does your AFM supplement say? Mine says "IFR and terminal navigation is prohibited unless the pilot verifies the current mess of the database or verifies each selected waypoint for accuracy by reference to current approved data."

Since the arc on that approach is outside the FAF, it's "terminal" navigation, so if I verify my DME waypoint, I can use it without a current database for that portion of the approach.

 

[Velocity173]

I've been told by a couple different controllers (different facilities) that as long as you are on radar, they don't care what you use to navigate (we were IMC), including the GPS from your car (OK, I made the 'car GPS' part up). I have no FAR or other cite to back them up on it. Absent radar, no clue. YMMV!

Jim

What you've probably heard is exceptions to the operational service volume of the NAVAID. AIM 5-1-8 covers this as well as chapter 4 of the controllers manual. It still doesn't allow the use of a VFR GPS for nav while operating under IFR. It does however allow the controller to provide navigational assistance (vectors) and radar monitoring if you're / U and outside the NAVAID service volume.

"N12345, fly heading 360, when able proceed direct XYX VORTAC."

 

[jsstevens]

We were in radar coverage the whole time, and as I said, we were VFR simply for practice approaches etc. today so no legal issues at all.

Hmm. So if it was a 430 or even a 650 with an out of date database is it legal to use as a DME substitute?

John

 

[James331]

Depends on what the docs for the plane/GPS say

 

[MauleSkinner]

Oops...I read it as being VFR because of the database issue...the Garmin 100 can't be used IFR in any form. (Your AFM Supplement will still indicate that.)

 

[USAF JD]

I took my IFR check ride in a no GPS or DME bird. The DPE had me fly an approach using the IPAD for DME. He stated that he wants me to use everything available to me and to fly how I would in "real Life". We both agreed that it was not legal to do so...

 

[Greg Bockelman]

I took my IFR check ride in a no GPS or DME bird. The DPE had me fly an approach using the IPAD for DME. He stated that he wants me to use everything available to me and to fly how I would in "real Life". We both agreed that it was not legal to do so...

That is all well and good but the DPE should not have asked you to do that. That was not a "Real Life" situation. If you cannot legally do it in the real world, he should not ask you to do it on a checkride.

If you would have exercised your simulated emergency authority, however, that would fly with me.

 

[somorris]

It is my understanding that a VFR GPS (panel mount or portable) can be used for "situational awareness" on an IFR flight but cannot be used as the primary means of navigation. If you are in and will remain in radar coverage and ask for vectors, then the vector becomes the primary means of navigation. The VFR GPS then is only for situational awareness. This has been working well in the system for a while so I hope this does not change.

 

[jsstevens]

It is my understanding that a VFR GPS (panel mount or portable) can be used for "situational awareness" on an IFR flight but cannot be used as the primary means of navigation. If you are in and will remain in radar coverage and ask for vectors, then the vector becomes the primary means of navigation. The VFR GPS then is only for situational awareness. This has been working well in the system for a while so I hope this does not change.

This is what I thought. I can use anything I have for situational awareness but not primary navigation.

So under IFR accepting an approach with DME required and a VFR only GPS (even one with RAIM) is not legal?

John

 

[TheGolfPilot]

This is what I thought. I can use anything I have for situational awareness but not primary navigation.

So under IFR accepting an approach with DME required and a VFR only GPS (even one with RAIM) is not legal?

John

No it is not legal. You'd be just as illegal using an IPad but with more situational awareness.

To use a gps in lieu of dme it must be an IFR certified gps. It doesn't have to be current (pilot must check accuracy though), but it does have to be a certified GPS

 

[jsstevens]

No it is not legal. You'd be just as illegal using an IPad but with more situational awareness.

To use a gps in lieu of dme it must be an IFR certified gps. It doesn't have to be current (pilot must check accuracy though), but it does have to be a certified GPS

As best I can determine (without the plane here to look at) it is a Garmin 150XL, which once upon a time was IFR certified (not approach). There are no longer database updates for it (for a number of years!) so despite being IFR certified when it was installed, it is now VFR only. So it was (is?) IFR certified but the database it out of date (because they haven't made a new one in years). Based on the statement (italics & bold) above, is it legal as a DME substitute? I'd like to know before we file and fly under IFR.

John

 

[midlifeflyer]

I've been told by a couple different controllers (different facilities) that as long as you are on radar, they don't care what you use to navigate (we were IMC), including the GPS from your car (OK, I made the 'car GPS' part up). I have no FAR or other cite to back them up on it. Absent radar, no clue. YMMV!

Jim

What you've probably heard is exceptions to the operational service volume of the NAVAID. AIM 5-1-8 covers this as well as chapter 4 of the controllers manual. It still doesn't allow the use of a VFR GPS for nav while operating under IFR. It does however allow the controller to provide navigational assistance (vectors) and radar monitoring if you're / U and outside the NAVAID service volume.

"N12345, fly heading 360, when able proceed direct XYX VORTAC."

During the early years of GPS when not that many folks had panel mounts but many had handhelds, there was a widespread "hint-hint-wink-wink" between pilots and ATC based on two things. One is the comment in AIM 5-1-8.c that ATC is only supposed to give a direct off-airway route when in radar contact (See AIM 5-1-8.c.). The other is @TheGolfPilot's observation that ATC doesn't really care what you do so long as you don;t create a problem for them.
--
Sometimes it was unstated but the above-board version wen't something like this:

ATC: Proceed direct [Airport 200 NM away]
Pilot: Unable direct, but my handheld GPS shows about 230 to [Airport].
ATC: Fly heading 230; direct [Airport when able].​

After that, the pilot would just follow his magenta line and no one cared.

But officially, no. IFR certification is required for IFR navigation. Everything else is for situational awareness and anything can be used for it.

 

[TheGolfPilot]

Just fly /u and skip the DME. That approach is a vor/dme-a approach. DME is not required to fly the vor part. You can fly the approach from coopy or with vectors, legally, Safely, and without dme. If DME was required it would say DME REQUIRED a crossed the top.
Kind of like vor/gps approaches. You don't have to have a gps for those either


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[jsstevens]

Just fly /u and skip the DME. That approach is a vor/dme-a approach. DME is not required to fly the vor part. You can fly the approach from coopy or with vectors, legally, Safely, and without dme. If DME was required it would say DME REQUIRED a crossed the top.
Kind of like vor/gps approaches. You don't have to have a gps for those either


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Indeed. I used vectors for the ILS into ORL today. And today we were practicing the arc under VFR so it's good practice without a DME. Hopefully the other airplane is on line soon. It has two VOR/LOC receivers (1 with GS) and an honest to goodness DME. The ADF is INOP, but that's no big deal.

Someday an IFR GPS...

John

 

[TheGolfPilot]

Just fly /u and skip the DME. That approach is a vor/dme-a approach. DME is not required to fly the vor part. You can fly the approach from coopy or with vectors, legally, Safely, and without dme. If DME was required it would say DME REQUIRED a crossed the top.
Kind of like vor/gps approaches. You don't have to have a gps for those either


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I think I might be wrong here. I was thinking about something else and I got it confused with this and now I'm second guessing. For some reason I picked up somewhere that / meant or. Can someone clarify

 

[MauleSkinner]

As best I can determine (without the plane here to look at) it is a Garmin 150XL, which once upon a time was IFR certified (not approach). There are no longer database updates for it (for a number of years!) so despite being IFR certified when it was installed, it is now VFR only. So it was (is?) IFR certified but the database it out of date (because they haven't made a new one in years). Based on the statement (italics & bold) above, is it legal as a DME substitute? I'd like to know before we file and fly under IFR.

John

Look in your AFM Supplement.

 

[jsstevens]

Look in your AFM Supplement.

What, specifically, am I looking for? I know the GPS is no longer current. I can verify if it WAS IFR when installed. (And the airplane is not here, where I am.) Assuming it WAS IFR certified when installed, does it fall under the "not current database" but can be used in place of DME?

John

 

[German guy]

[...] To use a gps in lieu of dme it must be an IFR certified gps. It doesn't have to be current (pilot must check accuracy though), but it does have to be a certified GPS

This is also my understanding. We also already discussed the database currency issue. The pilot must verify that the relevant information is current - as no VORs have been added for years, even a older database should still include all of them, what would be entirely sufficient, if its only purpose is to use it in lieu of a DME.

I actually have written statement by the local FSDO in which they state that in order to use a GPS in lieu of a DME, the entire installation has to be IFR certified. This is particularly important, as quite a few planes are equipped with IFR capable GPS, however without the usually required CDI, annunciators and the related paperwork. Such a VFR installation of a generally IFR capable GPS does not qualify for being used in lieu of a DME.

Btw.: A VFR GPS (or even an iPad) can legally be used for most of the enroute navigation, as long as the same route could also be flown with the on board IFR-legal equipment. This means that one could not fly GPS airways, but very well fly ‘direct’ to a distant airport or a navigational aid, as this would also be possible with the compass / DG, which are a part of the IFR instrumentation. When I file an IFR flight plan, I therefore add the comment ‘VFR GPS for guidance on board’ and also try to include a VOR at the beginning and the end of my route, in case I would have to rely on my VOR receiver and lose communication or radar contact (what sounds like a unlikely combination). So far, ATC has been treating me as if I had an IFR GPS in the plane, only that I cannot fly approaches which require a full blown IFR GPS installation.

 

[James331]

As best I can determine (without the plane here to look at) it is a Garmin 150XL, which once upon a time was IFR certified (not approach). There are no longer database updates for it (for a number of years!) so despite being IFR certified when it was installed, it is now VFR only. So it was (is?) IFR certified but the database it out of date (because they haven't made a new one in years). Based on the statement (italics & bold) above, is it legal as a DME substitute? I'd like to know before we file and fly under IFR.

John

You can still get the databases for those, Jepp provides them and I doubt will end the service anytime soon, after all how hard it is to export the same data just in (guessing) a slightly different format.

http://jeppdirect.jeppesen.com/main/store/legal/charts/ads-overview.jsp

Looks like the 150/150XL and 250/250XL are VFR boxes but the 155/155XL, 165 and 300/300XL are IFR boxes. All of which can currently be updated through Jepp.

 

[German guy]

[...] Assuming it WAS IFR certified when installed, does it fall under the "not current database" but can be used in place of DME? [...]

Yes - just make sure that the VOR you want to use for DME is in the database.

 

[TheGolfPilot]

I think the idea is that you should just file and fly what you have current on board and you can surprise atc with the ability to do a little bit more if need be.
I fly a plane with an old GPS and file /u with it. I use my iPad sometimes to get direct vectors or such but limit my approaches to /u approaches. After reading a few things online I'm pretty sure now vor/DME requires the DME to fly it but it goes back to what was mentioned earlier, as long as you don't screw up it doesn't matter. But when you do its your life, and your passengers life at risk.


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[MauleSkinner]

What, specifically, am I looking for? I know the GPS is no longer current. I can verify if it WAS IFR when installed. (And the airplane is not here, where I am.) Assuming it WAS IFR certified when installed, does it fall under the "not current database" but can be used in place of DME?

John

You'd need a statement similar to this...

What does your AFM supplement say? Mine says "IFR and terminal navigation is prohibited unless the pilot verifies the current mess of the database or verifies each selected waypoint for accuracy by reference to current approved data."

Since the arc on that approach is outside the FAF, it's "terminal" navigation, so if I verify my DME waypoint, I can use it without a current database for that portion of the approach.

 

[Witmo]

Btw.: A VFR GPS (or even an iPad) can legally be used for most of the enroute navigation, as long as the same route could also be flown with the on board IFR-legal equipment. This means that one could not fly GPS airways, but very well fly ‘direct’ to a distant airport or a navigational aid, as this would also be possible with the compass / DG, which are a part of the IFR instrumentation. When I file an IFR flight plan, I therefore add the comment ‘VFR GPS for guidance on board’ and also try to include a VOR at the beginning and the end of my route, in case I would have to rely on my VOR receiver and lose communication or radar contact (what sounds like a unlikely combination). So far, ATC has been treating me as if I had an IFR GPS in the plane, only that I cannot fly approaches which require a full blown IFR GPS installation.

I believe you are making too great a stretch to believe that your compass and DG allow you to fly direct under IFR, to a waypoint that is not a VOR or other navaid like a NDB using a VFR GPS. Under IFR, you need to be in radar contact, on vectors, to go off airways if you don't have some sort of legal area nav, RNAV or IFR GPS. Compass, DG, DED Reckoning, VFR GPS don't hack it.

Just because ATC allows you to do something doesn't make something illegal, legal. If you ask for an ILS, ATC assumes you have everything to fly the requested approach. If you request direct own navigation, ATC assumes you have the legal requirements. If you don't and things go awry for any reason or even if the FAA gets wind of it some other way, it's gonna be your ticket that suffers.

 

[somorris]

"So under IFR accepting an approach with DME required and a VFR only GPS (even one with RAIM) is not legal?"

Check your approach plate, John. One I use frequently says "DME or RADAR required." If radar is available, you don't have to have DME.

 

[dmspilot]

That approach is a vor/dme-a approach. DME is not required to fly the vor part. You can fly the approach from coopy or with vectors, legally, Safely, and without dme. If DME was required it would say DME REQUIRED a crossed the top.

Noooo.

If DME is in the name of the approach, is required. This does not preclude adding "DME required" to an approach if it's not already in the name. A look at the approach mentioned by OP reveals DME is the only method available to identify the MAP.

Kind of like vor/gps approaches.

Those were "VOR or GPS xxx" not "VOR/GPS xxx".

 

[TheGolfPilot]

Noooo.

If DME is in the name of the approach, is required. This does not preclude adding "DME required" to an approach if it's not already in the name. A look at the approach mentioned by OP reveals DME is the only method available to identify the MAP.



Those were "VOR or GPS xxx" not "VOR/GPS xxx".

Yes, you are right, thank you. I was thinking about a Catalina approach and that is what made me say that. Shortly after saying that I looked a a more local vor/DME approach and realized I had it all wrong because there is no way to fly that approach without DME.

 

[aterpster]

If DME is in the name of the approach, is required. This does not preclude adding "DME required" to an approach if it's not already in the name. A look at the approach mentioned by OP reveals DME is the only method available to identify the MAP.

DME can also be mandatory when the chart has a note that states "DME Required." DME is in the title when DME is required for the final approach segment. But, if DME is required for procedure entry or the missed approach then it is a note rather than in the title.

Those were "VOR or GPS xxx" not "VOR/GPS xxx".

Officially known as overlay approaches of either VOR or NDB approaches. That was done en masse at the beginning of the IFR GPS program to "prime the pump" so to speak. The policy the last few years is to delete the overlay portion from an overlay VOR or NDB approaches when they come up for revision.

 

[coma24]

Just fly /u and skip the DME. That approach is a vor/dme-a approach. DME is not required to fly the vor part. You can fly the approach from coopy or with vectors, legally, Safely, and without dme. If DME was required it would say DME REQUIRED a crossed the top.
Kind of like vor/gps approaches. You don't have to have a gps for those either

Disagree...violently. The title of the approach describes the equipment required to fly the approach from the FAF to the MAP. Just by the title of the approach alone (VOR/DME-A), I can tell you that it's a non-starter without DME (or an IFR-certified GPS substitute for the DME). Actually looking at the approach, you can see the reason why. Regardless of whether you're flying from COOPY or with VTF, how are you supposed to identify the missed approach point without DME?

If DME was required, it would be in the title of the approach, which....it is. A note that says, "DME Required" would imply that it's required for segments other than the final approach segment.

 

[Larry in TN]

Under IFR, you need to be in radar contact, on vectors, to go off airways if you don't have some sort of legal area nav, RNAV or IFR GPS.

That is not true. You can go off-airways as long as you are within the service volume(s) of the NAVAID(s) that you are using and are in compliance with the minimum altitudes specified in 14CFR91.177.

See AIM 1-1-17, particularly 1-1-17.b.2., for information on using GPS under IFR.

 

[TheGolfPilot]

Disagree...violently. The title of the approach describes the equipment required to fly the approach from the FAF to the MAP. Just by the title of the approach alone (VOR/DME-A), I can tell you that it's a non-starter without DME (or an IFR-certified GPS substitute for the DME). Actually looking at the approach, you can see the reason why. Regardless of whether you're flying from COOPY or with VTF, how are you supposed to identify the missed approach point without DME?

If DME was required, it would be in the title of the approach, which....it is. A note that says, "DME Required" would imply that it's required for segments other than the final approach segment.

Read past that post and you'll see I disagreed with myself

 

[Witmo]

That is not true. You can go off-airways as long as you are within the service volume(s) of the NAVAID(s) that you are using and are in compliance with the minimum altitudes specified in 14CFR91.177.

See AIM 1-1-17, particularly 1-1-17.b.2., for information on using GPS under IFR.

Tell me how under IFR, you can go direct to a fix or airfield not collocated with a navaid, without RV or IFR approved Area Nav of some sort. Sure I can go off airways direct to a navaid if I'm within the service volume of the navaid and above the minimum altitude you reference. What I can't do under IFR, is go direct to a fix or airfield off airways unless it's collocated with the navaid unless I'm radar vectored or have approved Area Nav onboard. A VFR GPS doesn't cut it, nor does a VOR and DME alone.

 

[Palmpilot]

Tell me how under IFR, you can go direct to a fix or airfield not collocated with a navaid, without RV or IFR approved Area Nav of some sort. Sure I can go off airways direct to a navaid if I'm within the service volume of the navaid and above the minimum altitude you reference. What I can't do under IFR, is go direct to a fix or airfield off airways unless it's collocated with the navaid unless I'm radar vectored or have approved Area Nav onboard. A VFR GPS doesn't cut it, nor does a VOR and DME alone.

I think he was talking about navigating along a VOR radial.

 

[tree96]

so with a 430, load and activate the approach then flying past the VOR will the dme fixes on the moving map be correct? I know the cdi VOR head needs to be the primary nav source, the aim or my lack of reading comprehension made it fuzzy for me...

 

[aterpster]

so with a 430, load and activate the approach then flying past the VOR will the dme fixes on the moving map be correct? I know the cdi VOR head needs to be the primary nav source, the aim or my lack of reading comprehension made it fuzzy for me...

Perhaps; perhaps not. My group posed that very question to the FAA several weeks ago. The preliminary response was that they had not thought of that. But, a definitive answer may be a long time coming. In the meantime, as a Part 91 operator, I would do as you propose. Those fixes on the moving map are indeed correct assuming a current database and a reasonable map scale.