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430W loss of signal yesterday

Geeman

Well Known Member
I was flying in and around Mount Shasta (Northern California) north of Redding and received message on the 430W that I lost GPS signal. I was at 11,500 on north side of a 14,000 mountain. It came back about 5-10 minutes later as I was southbound.

I was enroute from Redding area for Lake Tahoe and doing a practice VFR GPS 18 approach into South Lake Tahoe. Between the IAF and the FAF about 8500 ft I lost the signal again. It came back just before the missed approach point.

During this time I had foreflight on an IPAD and never lost position on the map. I also had a 696 and it showed me on the moving map but I lost the approach course on the 696 that the 430 sends to it.

Question 1: Do you think this was an antennae issue or a GPS loss of signal in the area? Did it not have enough antennas in sight for the 430, but enough to run the ipad/696?

Question 2: I was in VMC. What the heck would you do in IMC during a "real approach". Lets say I did not have the IPAD or 696. The missed approach is a GPS waypoint, how would you navigate to it. What if you could not get ATC for a vector due to mountains. I realize I was over the lake and could have done a 180 and climbed over the lake...but that is not the published route. I also realize this would be an emergency and do what I needed to do to, but what is the recommended course of action?

Never had this happen before. Flown behind a few 430's.
 
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loss of gps

Well there was a time before GPS. And basically when we are following the magenta line, we are on a heading. The maps and charts whether paper or on iPad do show headings. So overall navigation is doable for awhile. Under VFR I'm not sure its an emergency. Asking center for a vector is ok. Even the approach is all about headings. But if your GPS is driving your OMNI needles during an approach and they went south you'd have to go missed and perhaps find an ILS or VOR approach. If you are IFR relying on /G that's probably an emergency.
 
I was flying in and around Mount Shasta (Northern California) north of Redding and received message on the 430W that I lost GPS signal. I was at 11,500 on north side of a 14,000 mountain. It came back about 5-10 minutes later as I was southbound.

I was enroute from Redding area for Lake Tahoe and doing a practice VFR GPS 18 approach into South Lake Tahoe. Between the IAF and the FAF about 8500 ft I lost the signal again. It came back just before the missed approach point.

During this time I had foreflight on an IPAD and never lost position on the map. I also had a 696 and it showed me on the moving map but I lost the approach course on the 696 that the 430 sends to it.

Question 1: Do you think this was an antennae issue or a GPS loss of signal in the area? Did it not have enough antennas in sight for the 430, but enough to run the ipad/696?

Question 2: I was in VMC. What the heck would you do in IMC during a "real approach". Lets say I did not have the IPAD or 696. The missed approach is a GPS waypoint, how would you navigate to it. What if you could not get ATC for a vector due to mountains. I realize I was over the lake and could have done a 180 and climbed over the lake...but that is not the published route. I also realize this would be an emergency and do what I needed to do to, but what is the recommended course of action?

Never had this happen before. Flown behind a few 430's.




This sounds a lot like a GPS interference testing issue. Did you check the notams? I was southbound through Florida and my 650 lost all position data. My G3X never lost the position lock, but the 650 was out to lunch. Jax center did not have any information when I asked, so I thought I had a problem. Needless to say, I spent days checking wiring and was almost ready to ship the 650 back to Garmin with its associated cost:eek:, when I went back and found the website. And yes, it was listed for the day I flew.

The testing WILL take out any WAAS receiver but wont hurt a Non-WAAS.
 
Q2: This is where position awareness is everything. I was up there just a few weeks ago, and ATC radar does not reach down into the lake basin. If you're aware of where you are, then it's obvious (?) that you need a climbing right turn to stay out over the lake while you climb. If you start low, you'll need to turn the turn into a circle. If the wind is the usual out of the west, you'll want to slightly favor going more west than east on each turn, to stay over the lake. When you get high enough ATC will see you and can vector you somewhere.

And yes, gps outages/interference happen. About a few months ago, going into LVK (VFR, "student" under the hood) the 650 first downgraded from LPV to LNAV; then, a big red X and no gps.
 
Since your ipad and 696 didn't lose signal, it wasn't jamming. Several years ago I had intermittent loss of signal on my 430w. I don't fly IFR so I decided to wait until it conked out for good. Anyway, it never did but it was a faulty antenna. I used to get the error every couple months or so, and it would come back after several minutes. It's been a number of years since replacing the antenna and the problem has never recurred.
 
I have no advice at all about IFR, but when I discovered that the EFIS I'm using will allow a 'backup' gps, I bought one of the cheap pucks that can see all the different countries' constellations. The one I've got lets you pick two constellations, so...if the gubmnt is monkeying with gps, GLONASS or another constellation might be still available.

For VFR me, it's more of a convenience thing, but I wonder if it might be a plan C or D, even in an IFR environment.
 
Loss of GPS signal

I was loosing GPS reception to my 400W. It was caused by my iLevil ADSB/GPS receiver being located too near my glare shield mounted Garmin antenna. The problem was easily identified by turning the Garmin to the reception strength screen and moving the iLevil (also turned on) toward the Garmin antenna. The bars dropped down rapidly as the iLevil got closer to the Garmin antenna. John
 
I was loosing GPS reception to my 400W. It was caused by my iLevil ADSB/GPS receiver being located too near my glare shield mounted Garmin antenna. The problem was easily identified by turning the Garmin to the reception strength screen and moving the iLevil (also turned on) toward the Garmin antenna. The bars dropped down rapidly as the iLevil got closer to the Garmin antenna. John

Maybe on to something. I just put a spot gps tracker in the plane the day before. It?s about 30? away from the GPS antenna. Maybe I should move it. :confused:
 
I lost my 430 signal a couple of times on a long x ctry trip. Moved the antenna from under the cowl to the top of the turtle deck and have never had one since. Not sure if it was heat or shadowing from the near by firewall.

Larry

Larry
 
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Antenna

I had same issue. Intermittent at first the progressively happened more often. New antenna solved the issue. Do a search but there were stories of a possible bad batch of antenna, it was never a proven theory. Garmin thought the screws might have been torqued to much. I was careful to install the new one.

Second GPS is my back up, Aera 660.


Cheers
 
This sounds a lot like a GPS interference testing issue. Did you check the notams? I was southbound through Florida and my 650 lost all position data. My G3X never lost the position lock, but the 650 was out to lunch. Jax center did not have any information when I asked, so I thought I had a problem. Needless to say, I spent days checking wiring and was almost ready to ship the 650 back to Garmin with its associated cost:eek:, when I went back and found the website. And yes, it was listed for the day I flew.

The testing WILL take out any WAAS receiver but wont hurt a Non-WAAS.

I went back and looked at ARTCC notams and it did mention GPS unavailable in certain areas. Very likely the issue. Note to self. Pay extra attention to notams when flying a GPS approach in IMC. Must be why you need a non GPS approach for your alternate. I try and pick alternates with ILS.
 
This regulation (91.167) applies to civil aircraft regardless of the equipment used for navigation (e.g. GPS/WAAS).

However, if your aircraft has a properly installed and operated GPS (see the TSO requirements in the AIM/AC references below) you can flight plan to your destination and alternate as follows:

TSO-C129() and TSO-C196() equipped (GPS aircraft) - Either the destination or alternate, but not both, can offer only a GPS approach (no other type approaches need be available)

TSO -C145/-C146 (WAAS Equipped Aircraft) - Both the destination and the alternate can be airports with only GPS approaches available.

References: AIM 1-1-17 b 5 c/d, 1-1-18 c 9 a. AND AC-105A, paragraph 9.5.1
 
Maybe on to something. I just put a spot gps tracker in the plane the day before. It?s about 30? away from the GPS antenna. Maybe I should move it. :confused:

Definitely move the Spot! We were flying out Tundra from home to the Idaho back country last year (about a four hour trip in that slow boat), and noticed the Dynon GPS dropping out on a regular, peridic basis. Without much better to do, we started watching thing, and every time the Spot did a position update, we had a loss of GPS. The SPOT was thrown up on the glareshield right near the GPS antenna. We moved the spot off to the side of the glare shield, and the problem went away!

Empirical, but repeatable....

Paul
 
Just lost all bag while IMC

Flying back last week from Dallas to Milwaukee lost GPS and VOR on my Avidyne while IMC.

After a few choice words I notified ATC that I lost Navigation equipment. They asked if I wanted to declare an emergency. I said no all other systems on line. Asked for minimum vectoring altitudes to my destination which I figured would work given ceiling forecast At 4K. I was at 9K. I quickly switch autopilot off nav mode onto heading mode and they gave me vectors and decents. All went well. I joked with ATC that I went from a slant golf to a slant nothing. All I had was my iPhone for navigation. I need a better backup. iPad Is WiFi only.

Now I have to trouble shoot the GPS.

What would I have done if ceilings were lower? I think request vector to VFR. I had the gas.
 
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Non GPS Approaches/Alternate

This regulation (91.167) applies to civil aircraft regardless of the equipment used for navigation (e.g. GPS/WAAS).

However, if your aircraft has a properly installed and operated GPS (see the TSO requirements in the AIM/AC references below) you can flight plan to your destination and alternate as follows:

TSO-C129() and TSO-C196() equipped (GPS aircraft) - Either the destination or alternate, but not both, can offer only a GPS approach (no other type approaches need be available)

TSO -C145/-C146 (WAAS Equipped Aircraft) - Both the destination and the alternate can be airports with only GPS approaches available.

References: AIM 1-1-17 b 5 c/d, 1-1-18 c 9 a. AND AC-105A, paragraph 9.5.1

I must have misinterpreted that. I seem to remember the alternate had to have a non GPS approach. Well, this could get ugly quick.....no GPS signal on the 430W, weather getting lower, an ILS is too far for fuel, after you flew to destination and alternate with only GPS approaches. Kind of makes you rethink your strategy with weather, fuel, approaches. As they say, you only have too much fuel if your on fire. I just installed Hotel Whiskey ER tanks. I like them better already.

Thanks for all the input. Always learning.
 
WAAS's selling point is that CFR benefit, but yes, not without outage and failure risk. Risk/Reward still favors WAAS. Outage NOTAMS, safe personal mins, enough fuel- all being a good pilot.
 
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