What was found
INBOUND IN TO DTW (FLIGHT 4284) ON APPROACH RECEIVED A FLAP FAILS MESSAGE AT 0 DEGREES. AIRCRAFT LANDED SAFELY. PERFORMED CRJ200 FLAP HEALTH CHECK IAW CHECKLIST. PERFORMED TROUBLESHOOTING PER BOMBARDIER FIM REV 44 IAW AD 2009-06-12 PARAGRAPH (H) (6) (I), AMOC DATED DECEMBER 07, 2012 AND PA AD27 - 052J. FOUND LEFT BPSU OUT OF RIG. RIGGED LEFT BPSU IAW AMM 27-53-10. REMOVED AND REPLACED RIGHT OUTBOUND FLAP OUTBOUND ACTUATOR BOLT WITH SERVICEABLE IAW CRJ AMM CHAP 27-53-01. PART NUMBER NAS6707D25 PER IPC 27-53-00. REMOVED AND REPLACED RIGHT FLAP SHAFTS 1, 2, 5 IAW CRJ200 AMM27-53-10.