My GNS430W is lost!
Thread Starter
My GNS430W was not lost after all!
I have 500+ hrs with the G430/530 flying all over Australia and I have never before seen anything like this.
I would be interested to know if anyone else has had a similar experience to the following:
Yesterday my G430W went bush going into Tindal! I had a YBMA-TEXAN-BARON-YPTN flightplan active. The final waypoint was YPTN, which I assume is the aerodrome reference point, rather than TN (for the NDB or VOR) because this is the correct way to do it with a G430/530 - it lets you then call up arrivals and approaches for that aerodrome.
About 30 nm out from Tindal, it became apparent that something was amiss. I could see where the aerodrome was, and the Garmin 496 portable on the yoke was indicating what would have been the correct track to the aerodrome, but the GNS430W, which was connected to the autopilot at the time, was headed for somewhere well east of the actual Tindal aerodrome. The point on the 430 map display that was marked as YPTN was not where the aerodrome was actually located.
In hindsight it would have been interesting to set it up for an RNAV Appr and see what happened, but I didnt think of that until after I had landed.
Can anyone suggest something I might have missed?
Does anyone know where you report apparent GPS anomalies?
I will probably go back through Tindal on Friday and will fly an RNAV appr (in VMC).
Dr
PS: My faith in GPS technology has taken a bit of a beating!
I would be interested to know if anyone else has had a similar experience to the following:
Yesterday my G430W went bush going into Tindal! I had a YBMA-TEXAN-BARON-YPTN flightplan active. The final waypoint was YPTN, which I assume is the aerodrome reference point, rather than TN (for the NDB or VOR) because this is the correct way to do it with a G430/530 - it lets you then call up arrivals and approaches for that aerodrome.
About 30 nm out from Tindal, it became apparent that something was amiss. I could see where the aerodrome was, and the Garmin 496 portable on the yoke was indicating what would have been the correct track to the aerodrome, but the GNS430W, which was connected to the autopilot at the time, was headed for somewhere well east of the actual Tindal aerodrome. The point on the 430 map display that was marked as YPTN was not where the aerodrome was actually located.
In hindsight it would have been interesting to set it up for an RNAV Appr and see what happened, but I didnt think of that until after I had landed.
Can anyone suggest something I might have missed?
Does anyone know where you report apparent GPS anomalies?
I will probably go back through Tindal on Friday and will fly an RNAV appr (in VMC).
Dr
PS: My faith in GPS technology has taken a bit of a beating!
Last edited by ForkTailedDrKiller; 20th May 2009 at 07:08.
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Could it be a Jepp error? Check the data in the 430W against your Jepp charts. You may find the bug!
Interesting thing is who do you report it too.......well ATSB? Jeppersen? Where will it get taken seriously. If you flew the RNAV and wound up aiming at some blokes back paddock then you would have had an Incident to report!
I have also found the CTA steps on the G296 are not the same as a VTC around Brisbane. Which may explain why some folk get VCA's and why ATC get a lot of stress in their day!
Watch out for the PP up there to!
Interesting thing is who do you report it too.......well ATSB? Jeppersen? Where will it get taken seriously. If you flew the RNAV and wound up aiming at some blokes back paddock then you would have had an Incident to report!
I have also found the CTA steps on the G296 are not the same as a VTC around Brisbane. Which may explain why some folk get VCA's and why ATC get a lot of stress in their day!
Watch out for the PP up there to!
From Avweb...
GAO FIRES WARNING ON GPS
"It is uncertain whether the Air Force will be able to acquire new satellites in time to maintain current GPS service without interruption," warns the GAO. "If not, some military operations and some civilian users could be adversely affected." The report, issued April 30, notes the Air Force's struggle to successfully build satellites on time and on budget. According to the GAO, the Air Force is running $870 million over its original cost estimate and has delayed the launch of its next satellite (now scheduled for November 2009) by almost three years. As old satellites begin to fail, it is increasingly important that the Air Force does not fall behind its current schedule. Otherwise, warns the GAO, there is increased likelihood that by 2010, "the overall GPS constellation will fall below the number of satellites required to provide the level of GPS service that the U.S. government commits to." That shortfall "could have wide-ranging impacts on all GPS users." While many of the potential problems rely on the Air Force's success working with a new contractor, the GAO has made recommendations. More...
"It is uncertain whether the Air Force will be able to acquire new satellites in time to maintain current GPS service without interruption," warns the GAO. "If not, some military operations and some civilian users could be adversely affected." The report, issued April 30, notes the Air Force's struggle to successfully build satellites on time and on budget. According to the GAO, the Air Force is running $870 million over its original cost estimate and has delayed the launch of its next satellite (now scheduled for November 2009) by almost three years. As old satellites begin to fail, it is increasingly important that the Air Force does not fall behind its current schedule. Otherwise, warns the GAO, there is increased likelihood that by 2010, "the overall GPS constellation will fall below the number of satellites required to provide the level of GPS service that the U.S. government commits to." That shortfall "could have wide-ranging impacts on all GPS users." While many of the potential problems rely on the Air Force's success working with a new contractor, the GAO has made recommendations. More...
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GPS navigation
Remember it is an aid to navigation, it pays to keep a healthy respect to any situation and if possibile, have a second alternative navigation aid ,also set- up.
Tmb
Tmb
I think your 430W got a bit jealous because you payed too much attention to your 496. Just wait till the rest of your GPS's go on strike..... you will never find your way back home to annoy Jabba again.....
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This is probably unlikely given it's your own unit but I once flew a rented aeroplane and somebody had inserted a user waypoint of WOL, which is also the navaid identifier at Wollongong. During data entry I should have noticed that it said USER instead of NDB next to what I had selected, but instead only noticed it when the track/distance was a long way off.
Turn off SBAS
I'll bet it has SBAS or WAAS enabled.
When you are outside of SBAS coverage you need to disable SBAS or WAAS.
Go to AUX page 4 which I think is headed Setup 2 and you will find a label called "SBAS Selection". Highlight that selection and press enter. You should see WAAS and my bet is that it is ON. You need to turn it off.
In this part of the world we can receive the signals from the WAAS satellites but the correction factors are not for this part of the world and can cause significant errors for WAAS enabled GPS's.
I'd be interested to hear back from you after you check this out.
When you are outside of SBAS coverage you need to disable SBAS or WAAS.
Go to AUX page 4 which I think is headed Setup 2 and you will find a label called "SBAS Selection". Highlight that selection and press enter. You should see WAAS and my bet is that it is ON. You need to turn it off.
In this part of the world we can receive the signals from the WAAS satellites but the correction factors are not for this part of the world and can cause significant errors for WAAS enabled GPS's.
I'd be interested to hear back from you after you check this out.
Thread Starter
I'll bet it has SBAS or WAAS enabled
Dr
PS: But I will go check tomorrow in case someone has had a play with it - unlikely as I am the only person who flies the aeroplane.
Have a look at the EPU (estimated position uncertainty) values on Nav page 6 and the HFOM and VFOM for that matter if this happens again.
I know that there have been some isues with the 430/530W units having very high EPU values. I thought is was all to do with the SBAS issue but there may be more to it.
I know that there have been some isues with the 430/530W units having very high EPU values. I thought is was all to do with the SBAS issue but there may be more to it.
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And there is the lesson for those types who operate via D To ENTER!!, and hope/wish/pray/don't give a ****.
I don't mean you Dr, You've just demonstrated what can happen, even if you know what you're doing. Think about those that don't!
I don't mean you Dr, You've just demonstrated what can happen, even if you know what you're doing. Think about those that don't!
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I've had the exact same thing happen on the GNS430 in the Cirrus coupled to the autopilot and avidyne. I was heading towards the CBD with it clearly in site some 40 miles away, looked down for a while whilst reading the paper, looked up and I was headed for the mulbury. I did a re-goto and it put me back on track. I was kicking myself at the time that I didn't take enough notice of where it was actually trying to take me. This occurred around the time of the Benalla crash when I posted here and ATSB spoke to me at the time regarding GPS issues.
Not long after (couple of months) same thing happened on 296. Headed for Wangaratta, could clearly see the field no more than 10 miles ahead but the ETA was some 25 minutes which made no sense at all (unless I was in a Thruster which I surely wasn't). Yet again was kicking myself that I didn't look closely as to where it was actually trying to take me.
Both of these were some 2-3 years ago.
Not long after (couple of months) same thing happened on 296. Headed for Wangaratta, could clearly see the field no more than 10 miles ahead but the ETA was some 25 minutes which made no sense at all (unless I was in a Thruster which I surely wasn't). Yet again was kicking myself that I didn't look closely as to where it was actually trying to take me.
Both of these were some 2-3 years ago.
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could clearly see the field no more than 10 miles ahead but the ETA was some 25 minutes
As much as we often get away with things with phones, there are times when I wonder..... have seen it kill a transponders Mode C.... probably due to the encoder to transponder harness..... but it did.
This is possibly a database error, but I am sure the Dr will keep us informed, he has to get back to TL via there anyway!
J
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I have also found the CTA steps on the G296 are not the same as a VTC around Brisbane. Which may explain why some folk get VCA's and why ATC get a lot of stress in their day!
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I keep my 296 pretty much up to date and haven't had a problem with the steps. It does give a lot of warnings but they are fairly generic and if you're fast will pop up fairly early. eg,. airspace ahead within 10 minutes, which could be 20+ miles depending on your speed. If they are causing you problems you can of course filter them out so they don't appear.
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Steps and the warnings are fine, they have a distance and height buffer I think, its the actual steps on the map compared to the VTC that is wrong.
Back to the FTDK GNS430W issue......
Back to the FTDK GNS430W issue......
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....and how am I gonna do that now that my faith in GPS is totally destroyed?