What was found
FLAPS FAILED AT 20 ON APPROACH (2ND EVENT OF THE DAY). RIGGED LT BPSU IAW CRJ 900 AMM 27-51-10. PERFORMED TROUBLESHOOTING PER BOMBARDIER FIM REV 39, IAW AD 2009-06-12 PARAGRAPH (L) (G) (I), AMOC DATED MARCH 27, 2009 TR# 27-012 PER AMOC DATED DECEMBER 18, 2009 AND PA AD27-052G. OPS CHECK GOOD.