NOTICE ADVISORY TO NAVSTAR USERS (NANU) #064-91066 SUBJ: UNUSABLE: PRN12 65/1535-65/1700 & PRN13 65/2228-65/2243 1. FORECASTS/ADVISORIES AS OF DAY 64 (05 MAR 91): A. PRN12 (MCS: SVN10) WAS UNUSABLE ON DAY 65 BEGINNING 1535 UTC UNTIL DAY 65 AT 1700 UTC. B. PRN13 (MCS: SVN9) WAS UNUSABLE ON DAY 65 BEGINNING 2228 UTC UNTIL DAY 65 AT 2243 UTC. 2. RECOMMENDATION: CONFIRM AVAILABILITY OF SATELLITES PRIOR TO USE. 3. POINT OF CONTACT: MAJ WILLIAM FAUVER AT COMMERCIAL (719)550-6379 OR AUTOVON 560-6379.