'Direct' with VFR GPS


#1

My understanding is when operating IFR if you have a VFR GPS onboard you can request ‘direct with VFR GPS’ and if ATC clears you, it’s all legal.

I’ve done this several times over Thanksgiving when scootin between school and home. It saves me a lot of time! http://flightaware.com/live/flight/N8764E After copying the clearance I usually request it and they’ll amend it to direct on the ground.

I was wondering under what conditions will ATC grant this request? The obvious difference between a VFR and IFR GPS is the RAIMM capabilities for signal validation, so I’m guessing ATC will only grant it when you’re in a radar environment because they can “be your RAIMM” to ensure the GPS is accurate.

Has anyone else had any experience going direct under IFR with a VFR GPS?


#2

Many moons ago, long before GPS or even LORAN, I had a little scanner at home. I used to hear the airline that flew out of SBP, long before there was a tower, takeoff and call LA center for their clearance to Fresno. Somebody had figured out that after you cleared the ridge north of SBP you could fly a 015 heading and hit the outer marker at FAT. So that became the request. The first few times it was tried the controller would hem and haw and finally ask " how do you propose to navigate?" “dead reckoning” was the answer. That was all the controller needed, the clearance would be as requested and off the 4 engine DeHaviland noise converter would go.

I suspect that legally the controller is letting you use whatever means you want, including dead reckoning, it’s up to you to keep track of your navigation. Technically you could not use the VFR GPS for anything that requires an RNP and/or IFR approval. En route and under radar the controller is letting you slide a bit.

Thats my guess.

John in Saudi


#3

As a controller I’ve never heard anyone make that request, though that isn’t saying much. I have only have 7 years experience (military and FAA combined) and where I’m at now we don’t get much variety in our GA ops. For the most part controllers don’t care how you get from point A to point B. The biggest exception is probably in a non-radar environment because it’s harder to get your separation when everyone is going direct everywhere. Now if say an aircraft if filed as a C172/A I won’t initiate clearing them direct a fix, but if they say they want to go direct via their own navigation then I don’t have a problem giving it to them.


#4

I can’t say I’ve heard it since. I think it may have been a local pilot talking to controllers he recognized.


#5

Just don’t file /g (better yet, get caught) with a VFR GPS in your filing.

Problem I would have with the above is what if you had to do an actual approach? Especially to an airport that only has a GPS approved approach (no ground based approaches) and your VFR only GPS doesn’t have that capability.

What if ATC wanted to route you to an intersection that may not be in the VFR GPS database.?


#6

I don’t know the rules for part 91, but part 135 it’s a HUGE no no. I tried it once, I was going from KBNA to KFTY. I asked Memphis center for direct BUNNI for the BUNNI TWO arrival and he said “I show you as a /c (slant C) how are you going to nav to BUNNI?” I said I have a hand held GPS (really i had a working loran) and he ripped me a new one, saying that we aren’t allowed to use a hand held and that he was going to make me call the center when I was on the ground. He never gave me a number to call and I never asked for direct to an RNAV fix ever again.


#7

That one is easy- if you look in your in-route charts the lat-long is given next to the fix. just make a user waypoint and plug in the lat-long. I have to do that all the time when flying south of flordia with the fancy garmin we have in the lear


#8

I do not file /g. If I filed this it would mean I have GNSS with WASS. If I was equip. code /g then I could just go direct without the VFR GPS. I file /u ‘Transponder with Mode C’. Then, in the remarks section I often put ‘VFR GPS onboard’.

Thus, because VFR GPS is not normally approved for IFR ops I would only file a route to an airport that I can fly with the equipment stated in my equipment suffix. After copying the clearance I then explain ‘N***** requests direct with VFR GPS for navigation.’ So if they didn’t approve navigation via VFR GPS I could still complete the route as filed.

At this point I think it’s pretty explicit to ATC that the GPS is strictly VFR. If they tryed to route me to a GPS int. I would decline and they would have to put me back on VOR nav.

As far as going to an airport with ONLY a GPS approach… I’ve never heard of anyone using a VFR GPS for a GPS approach, but this is not something I would not try or recommend. Even if approach via VFR GPS is legal, which I highly doubt it is, it seems unsafe.


#9

So even if the controller approves a request ‘Direct with VFR GPS’ it’s the pilot’s responsibility to ensure IFR/RNP standards are met; despite, the request is specifically attempting to get approval for a navigation method that does not meet the standards? Interesting… this is contradictory to what I learned.

I’m looking through FARs to try and see what the real legalities on this are…

I appreciate all the feedback from everyone. It would be nice if I can find a defined answer on this for Part 91 ops.


#10

And specifically, the ATC facilities that have approved this request have been Quad Cities, Rockford, and Milwaukee


#11

Interestingly enough, all of these within the same ARTCC.

From the controller perspective, I was beginning to wonder how this would fly. If you’re requesting ‘direct VFR GPS’, wouldn’t you have to cancel IFR, since you’re wanting direct VFR? Yes, you can request direct while en route in either VFR or IFR, and if your request for direct to your destination spans across different sectors, coordination will need to occur. But I’ve never heard of any such request as ‘direct VFR GPS’… No mention of it in the 7110.65…

BL.


#12

Ok, gotchya, it wasnt’ clear to me in your original post whether you would file direct or not. This clear it up for me.

I take it you would initiate a reroute should the weather turn out IMC then the forecasted VFR conditions you expect? Otherwise you may find yourself in a pickle getting established for an approach? Of course you could fly direct to the IAF rather then the airport too.

You probably won’t hear it as I don’t think VFR GPS’s have approaches loaded in their database. I only brought this scenario up if the weather turned out worse, how would you get in since ATC sees “direct”, it’s assumed GPS capable IF and a big IF they don’t look at the remarks on the strip.

Personally, GPS direct is the way to go, and ATC I doubt would care how you navigate as long as you are “predictable” in your flight path. Only time I ever did airways was up in the NE, down here, if you file airways, first question inevitably is “do you want direct”. Of course, I do file /G which justifies the question.

The one time my GPS failed (antenna was not coupled securely on initial installation), I had filed direct, GPS didn’t phone home, so on call up to clearance and delivery, filed an amended flight plan via airways and intersections. Center got tired of me poking along and offered me one looooong vector which I gratefully accepted. I can follow directions :smiley: easy enough! Of course, this was the one time I didn’t have my handheld on me, and that has never happened again.


#13

I think I may not have been entirely clear in how I file.

Here is an example flight plan, with my intention of requesting direct with VFR GPS (blocks are numbered respectively):

  1. IFR 2. N8764E 3. PA28/U 4. 112 5.KGBG 6.2000z 7.070
    8.BDF V127 RFD V63 BAE
    9.KUES 10.1:20 11. VFR GPS ONBOARD
    12.5:00 13.KMKE 14.DANIEL K… 15.1
  2. BL on WH

As I mentioned in previous posts the route I file is consistent with my equipment code, /u. So they wouldn’t assume I can go direct. If I never requested ‘Direct with VFR GPS’ after copying my clearance in the plane they would never know I had any intention of flying direct and expect me to go via victor airways.

As far as landing and weather concerns I don’t see why there would be a problem. I fly direct to the IAF, which in my example is BAE (Badger) for KUES (Waukesha’s) ILS. In fact, when I request direct ATC has told me ‘We can clear you direct, but direct Badger, not Waukesha’

Although if for some unforseen reason I couldn’t get setup on an approach, I would get vectors, as ATC will only grant Direct VFR gps in a radar environment :wink:


#14

Controllers are not police of the FARs unless it effects our separation. We have a lot of rules which we need to know to just keep everyone separated. As far as RNP standards the only time i’ve ever been concerned with it is when it effects the amount of oceanic non-radar separation (RNP-10 or RNP-4) I need. Radar does have a lot to do with it because when all else false we can provide a vector.


#15

You are clearing up a lot for me on these subsequent posts. When I file direct, I file direct to the airport, not a fix. So you are set up for at least a ground based approach the way you amend your filing with ATC on the frequency.

For me, when I get closer, when I get my weather briefing, I decide on the approach and on call up to approach I have in mind what I want (or approach will tell me “expect”)

I then set up my Garmin 430 accordingly should an approach be needed or just fly direct to the airport.

I thought you were going direct to the airport, thus all my questions.


#16

The trick is to request 45,000 feet and you can get direct where ever you want (most of the time)


#17

Disregard that last post of mine- here is what we did in Alaska when we were flying in one of the several PA-31 that we had with no “approved” GPS.

You ask for RV direct and “suggest” a heading. The conversation might go like this.

"Center N45AE request DIR Dolphin VOR (400 NM away)"
The controller will see your equipment suffix and might say “N45AE turn left 120 dir DHP when able”

OR you might say “Center N45AE, can we get DIR DHP I think 120 will get me there”

Center “N45AE left 120 DIR DHP when able”


#18

And this is all outside of radar?


#19

HUH? where are you operating outside of radar? We have Radar in Alaska. Your question confuses me


#20

I just assumed you woud’ve been outside of radar because Alaska is so desolate.