I have been told that GPS Interference Testing is taking place. Several
folks are reporting a drop in signal which they then lose final glide
information. Several of our pilots had seriously intermittant GPS
signals on Monday, May 16. Here is an explanation:

http://www.navcen.uscg.gov/gps/gpsnotices and
http://www.navcen.uscg.gov/gps/gpsno...terference.pdf

Usually the tests are from 8pm-4am on most days for us here in NM.
They might only affect us on final glide on a good, long day.

From May 16-21, they are from 4pm-2am....this explains the trouble
pilots had yesterday.

From 22 June to 02 July, they will take place from 3pm-1am.

So, goe to the above site and check for your area, its possible your
area will be affected even if its not listed. Thermal tight, Soar high,
fly safe. # 711 reporting