NOTICE ADVISORY TO NAVSTAR USERS (NANU) #039-92074 SUBJ: PRN12 UNUSABLE 074/0200-074/0214 1. CONDITION: PRN12 (SVN10) WAS UNUSABLE ON DAY 074 (14 MAR 92) BEGINNING 0200 UTC UNTIL DAY 074 AT 0214 UTC. 2. USERS OF GPS ARE CAUTIONED THAT THE SYSTEM IS NOT YET FULLY OPERATIONAL. SIGNAL AVAILABILITY AND ACCURACY ARE SUBJECT TO CHANGE DUE TO AN INCOMPLETE CONSTELLATION AND OPERATIONAL TEST ACTIVITIES. 3. POC: 1LT SKINNER AT COMMERCIAL (719) 550-6379 OR DSN 560-6379.