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Old June 10th 16, 05:03 PM posted to rec.aviation.soaring
David Kinsell[_2_]
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Default GPS Interference Testing

No, was north of Denver which is farther away from Alamagordo.

Current GPS domestic notams should be visible he

http://tinyurl.com/prds7nr

They list two sets of coordinates, neither of which match the China Lake
coordinates which were listed in the original advisory note (which is
still on the web, btw). So maybe the original China Lake testing has
been canceled, replaced by similar testing in other locations?

All the information I've seen indicates a ground-based emitter, with an
upside-down wedding cake area of interference.

Maybe the old 302 is starting to kick the bucket, seems like an unusual
failure mode though.

-Dave





On Fri, 10 Jun 2016 09:23:40 -0600, Dan Marotta wrote:

Hi Dave,

Were you within 300 nm of Alamogordo? I haven't checked the notams, but
you could have gotten zinged by some of the continuous testing which
seems to go on there. BTW, do you know where the jamming is coming
from? If it's from orbit, being low in CO wouldn't matter too much, but
I suspect it's from ground based emitters.


On 6/10/2016 8:39 AM, David Kinsell wrote:
You should be loading up on lotto tickets, Dan.

Interestingly, I had a decent flight yesterday, everything seemed to be
working fine. Up until just before the landing pattern, when GPS
altitude indication started flipping between correct altitude, and 0.

It was just a couple minutes around 23:19 zulu, 5:19 pm local. IGC
file uploaded to OLC, no problem, you can pull it from region 9 US.
Got the two green dots from OLC, plane didn't start doing Dutch rolls
or anything, but it does seem strange that my trusty 302 would choose
June 9 to start acting up. Viewing the file on SeeYou shows what I was
seeing in the cockpit.

Down low in Colorado, wouldn't have thought the canceled China Lake
testing (whose notams never seem to go away) could be involved here,
but who knows?

-Dave




On Wed, 08 Jun 2016 20:06:23 -0600, Dan Marotta wrote:

I flew my Stemme from Minden to Moriarty yesterday (after a week of
soaring!) and had GPS coverage for the entire trip. Guess I got
lucky...


On 6/7/2016 8:13 AM, Eric Bick (ZN7) wrote:
Everyone out west seen this NOTAM re GPS interference testing. Covers
most of the western US - NoCal and SoCal soaring sites, OR, Nephi,
Parowan, other - and continues throughout June on selected dates.
https://www.faasafety.gov/files/notices/2016/Jun/

CHLK_16-08_GPS_Flight_Advisory.pdf