Yesterday I landed at Henderson NV for the first time so I was unfamiliar with the route, ATC had denied Class B entry and advised I fly under/around it to get into KHND. I approached from the NE so was vectored around Nellis then my squawk code was reset to 1200 and "resumed own navigation". That was all well and good until I passed over Lake Las Vegas at 3,000 msl, and the GPS signal just died on both the Garmin 396 and Grand Rapids EFIS. At least I knew it wasn't equipment related. What a shitty time for that to happen! Under B and in unfamiliar territory. I edged away from B towards Boulder then hugged in tight to the mountains hoping to stay clear while still navigating to KHND. Henderson picked me up on radar just as I was about to call them "aircraft 4 miles SW of the field at 4000 and against the ridge, are you on frequency"? From there it was uneventful and that was also the same time the signal was regained. Not fun and fairly stressful. Next time, when GPS navigation is that critical, I'll be sure to tune the VOR ahead of time. Anyone else have a similar experience to share?

Blckrck

I remember a few years ago the FAA would put our Notams that stated certain areas and times would be without GPS. Seems it was always east of the Sierras and west of Salt Lake. Best I can do for now.

On the trip we took a couple of weeks ago to Terlingua Ranch my friend in his 180 lost GPS signal on both his Garmin 396 and his iPad for a couple of minutes in the vicinity of Sonora Texas. Outage lasted for several minutes. He was low MVFR at the time but was fortunate to be near enough to a highway he picked that up until the GPS came back online. I was already at the ranch.

This is the notice I received (below). Looks like they might have jumped the gun. That would piss me off.


FAA Safety Team | Safer Skies Through Education
FLIGHT ADVISORY - GPS Interference Testing - Las Vegas, NV
Notice Number: NOTC6493


FLIGHT ADVISORY

GPS Interference Testing

NTTR 16-03

22-29 April, 2016

Las Vegas, NV

Centered at 371934N1154249W or the BTY043059.

The entire flight advisory may be accessed and downloaded at the following address:

https://www.faasafety.gov/files/notices ... visory.pdf

Pilots are advised to check NOTAMs frequently for possible changes prior to operations in the area. NOTAMs will be published at least 24 hours in advance of

any GPS tests.


This notice is being sent to you because you selected "Selected ATC Notices" in your preferences on FAASafety.gov. If you wish to adjust your selections, log into https://www.faasafety.gov/Users/pub/preferences.aspx where you can update your preferences.

Blackrock wrote:
.
That was all well and good until I passed over Lake Las Vegas at 3,000 msl, and the GPS signal just died on both the Garmin 396 and Grand Rapids EFIS. At least I knew it wasn't equipment related

I got this in my email a few days ago. Not sure if it is related, but maybe GPS operations were affected else where as well. I love the VOR suggestion for backup. What about those poor guys say flying a limited panel who have nothing but glass?

.
FAA Safety Team | Safer Skies Through Education

FLIGHT ADVISORY GPS INTERFERENCE TESTING April 14 and April 19, 2016 Off the coast of Charleston, SC.
Notice Number: NOTC6488

FLIGHT ADVISORY
GPS INTERFERENCE TESTING
CSG4 16-02
14 and 19 April, 2016
Off the coast of Charleston, SC.

Additional information is available at the downloadable link below:

https://www.faasafety.gov/files/notices ... visory.pdf

Yesterday when Justin and I were in Nevada my 496 lost signal and quit working for maybe 30 minutes. The funny thing was my IPad and foreflight was working fine.

I was with a gaggle of aircraft headed up to Kotzebue few years back when all the GPS's went to night mode at the same time. I have had it shut down a few times around Rainy Pass/ Hells gate so I am careful not to get too far in the scud in that area. Not a big deal most of the time I could see it would be a major pain trying to avoid airspace they need to change the color in the sky so it is easy to see.
DENNY

I've flown down the HND twice, both about this time of year in 2015 and 2014. Never denied entry into class B but I tried to get there as early as possible before it got really busy.

Both trips at least once I lost GPS due to jamming (which I expected as it was NOTAM'd). There is a lot of weird crap that goes on in Nevada. How many times do they need to test GPS jamming?

I had a rare Lorance handheld GPS antenna fail in a way that it wanted me to make continuous tight turn. I was MVFR deadheading to an airport from a pipeline at dusk. I don't trust computers.

Here's another issue with the Garmin 2/3/496's.

ELTs and the GPS signal. Read down about half way for the technical details.

https://www.backcountrypilot.org/forum/ ... =elt%20gps

Gump

Had a GPS antenna fail last year on a GTN. It failed in a manner that sent out some "looping signal." The garmin tech rep informed me that this is somewhat common. That antenna caused both GTN, and the handheld area 500 to loose all satellites. All units were on separate antennas. Turn one unit off at a time and see if signal comes back for the other GPS units, if it does then you likely have a bad antenna.

In Northern California we have GPS failures quite often on a direct line between Redding and Crescent City. Just north of a little town called Forks of the Salmon, many times all the GPS signals go out. We have a 430w, 496, iPad with a stratus, and a back up waas receiver. They all failed at the same time and all the status pages show no space vehicles in sight. It has happened many times in two separate aircraft. The signals come back approximately 30 miles S/E of Crescent City. There are a few MTR's in that area and we have always wondered if the jet jocks were out having fun. Anyhow,it is not very comforting while VFR on top.

Ohh goody, now their coming to my neck of the woods. Almost four weeks of testing.

FLIGHT ADVISORY GPS Interference Testing April 27–May 20, 2016 Salt Lake City, Utah
Notice Number: NOTC6499

FLIGHT ADVISORY
GPS Interference Testing
UTTR GPS 16-02
27 April – 20 May, 2016
Salt Lake City, Utah

Yahoo! That will be all kinds of fun in the SLC Valley. Wonder what kind of havoc that's going to create? hope it doesn't get somebody killed due to lack of situational awareness and/or collision with other aircraft.

I might have to fly over there just to re-experience all the fun of sudden GPS loss and dead reckoning to avoid busting bravo.

WTF? Have fun with that...

If you're denied access to a Bravo airspace, tell em you want them to facilitate your transit through any airspace that lies under the Bravo airspace. They are approach controllers for all the airspace. If they have to call a couple towers, it may be easier for them to just clear you through the Bravo a/s.

GPS quits? Drag out a sectional. No paper charts? The sectional on you IPad still works. Then look out the window.

MTV

mtv wrote:If you're denied access to a Bravo airspace, tell em you want them to facilitate your transit through any airspace that lies under the Bravo airspace. They are approach controllers for all the airspace. If they have to call a couple towers, it may be easier for them to just clear you through the Bravo a/s.

GPS quits? Drag out a sectional. No paper charts? The sectional on you IPad still works. Then look out the window.

MTV

Haha, Mike yes, all of that and they are good points. Maybe I should provide more details.

Nellis handles approach's from that side. They had Military exercises going on. The MOA's and Restricted airspace was chocked full of aircraft. I'd been listening to Nellis range control, approach, and Las Vegas approach for the prior 45-minutes and knew they were maxed out and then some. "Remain on range, we'll bring you in when we can" was heard repeatedly and that was before they had to deal with a jet leaking fuel. Even the fuel leak had to make multiple requests for RTB (return to base), that were denied and finally they had to pipe up and say they were just short of declaring an emergency before they got priority handling.

And remember that recording of the dip on the radio that was posted here just a few days ago? Yep, you guessed it, they had one of those guys on the radio too keeping us all entertained. "Ahh, ahh, approach this niner five seven one Zulu. I think we are about 40 miles west of Mormon Mountain VFR at 8,500 we are a little plane and I'm wondering if you can let is in, I mean will you give us permission to enter the MOA's. No wait we are 40 miles east of the Mount Wilson VOR not west like I sad before. This is niner five seven one Zulu..." you get the idea!

In short, those controllers had a cluster going on. Las Vegas was full of arrivals, too and were very apologetic; they had just changed runways and my route would cross the arrival path so I wasn't too concerned about diverting around on my own. They would have sent me off to BFE until they could deal with me. Been there, done that before so I knew it was faster for me "resume own navigation" and I understood that. My hat was off to them and I thought Nellis and Las Vegas handled everything very well.

It was after that, when I was tucked right in tight against the bravo core, like 1/2 mile, traveling 2 miles a minute when the signal dropped. I'm sure we can all do that math; 15 seconds isn't much time to self locate from a chart. How long ago did the signal drop before the GPS's flagged out? Was accuracy degraded before that? Sure I had FF as a backup, but the signal is probably gone, how accurate is that when positioning from cell towers? Didn't know but I couldn't trust it either. Land marks, yeah Lake Mead 5-miles away so I'll head for that, lots of towers on those hills, No way was there enough information to position myself, only to navigate further out from the bravo core while remaining low and avoiding towers and other aircraft. My eyes needed to be outside, not reading a map. I swung wide being pretty sure I was clear, like 90% sure, but that's not all that comforting especially when bravo was changing both horizontally (expanding) and vertically in front of me. I made it work, but it isn't an experience I'd wish on anyone else, especially someone with only a few hundred hours.

It is good that we can openly share our experiences, both the good and the bad, and can learn from one another. Being there in person tends to make it a lot more real; sort of like stepping in dog shit.

Got by with DME - VOR - and a little yellow AOPA ruler to take closest point of my route off of a CHART.

I'm just curious if some of the GPS units such as the Garmin GLO (which also can use the Russian GLONASS System) will continue to provide sufficient service when say the US GPS system is degraded or goes down for short durations during testing.





Links :
https://en.wikipedia.org/wiki/GLONASS
http://www.spaceflightinsider.com/missions/iss/russia-considering-halting-u-s-gps-stations/

The popular Garmin GLO GPS Unit uses both US GPS and Russian GLONASS
Link: https://buy.garmin.com/en-GB/GB/aviation/portable-gps/glo-for-aviation/prod109826.html

.
GLO for Aviation can receive position information from both the GPS and GLONASS satellite constellations, allowing it to connect to up to 24 more satellites than devices that rely on GPS alone. This allows GLO to lock on to satellites approximately 20% faster and keep up with even the most demanding jet speeds.

I am curious how well certain packages such as ForeFlight, Fly Q-EFB, and others cope when only fed a GLONASS sourced GPS signal.

Anyone?

Black rock,

It sounds you handled a difficult situation well.

I mean no offense here, but if you "have to find yourself" for some time after a GPS failure, you MAY be over reliant on GPS. Not being critical here.....I've been there myself.

When I was doing checkrides with PPL and especially IFR students, the GPS always seemed to die at the worst time. How well the applicant responded told me whether they were a "Child of the Magenta Line". That is not a complimentary term, by the way.

Respectfully, we should all KNOW where we are at any given time. GPS simply confirms that knowledge. It's an attitude.

Easy to say, a little harder to pull off, but this attitude will save ones butt sooner or later.

MTV

Yeah, reliance on the GPS and other electronics is such an attractive trap to fall into. They make life so easy, and nav a complete no-brainer, which in turn frees up the thinking power for fun stuff.

It's like auto-pilots. I cringe every time I hear a guy say that he'd never fly at night or any IFR without using the auto-pilot.

If you're proficient at Nav with a chart, whiskey compass, and a clock, electronics failure is merely a pain in the ass. A BIG pain in the ass, but still, nothing more.

On the other hand... Proficient at hand flying night/IFR, an equipment failure is pretty much a non-event. Dependent solely on the auto-pilot to stay right side up... You're gonna die.

Gump


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