What was found
FLAPS FAIL MSG. DURING AFTER START PROCEDURE WHEN FLAPS WERE SELECTED TO 20 DEGREES. PERFORMED R & R OF SKEW DETECTION UNIT IAW AMM 27-51-15. OPERATIONS TESTED GOOD IAW AMM 27-51-15. PERFORMED TROUBLESHOOTING IAW FIM CHAPTER 27-50-00 REV 48 IAW AD 1009 - 06 -12 PARAGRAPH H B I, AMOC LOG 14-105 DATED 12 30 2014 & TS 00100R1 FIM TECHNICAL SUPPLEMENT. FAULT CODES 51A, 111A,121B, 122B, 52A, 112A, 121A, 131B, 111B, 112B, 112B, 122A & 131A. SUSPECT SDU WAS NOT RESET AFTER BITE TEST IAW MEL 27-51-1A.