What was found
MCN - MAJOR REPAIR - DURING C-16 CHECK A 1.25 INCH CRACK WAS FOUND ON LOWER FRAME TO FRAME STRAP BS 312, RBL 26. MAINTENANCE FABRICATED A REPAIR DOUBLER, AND INSTALLED REPAIR TO LOWER FRAME TO FRAME STRAP BS 312, RBL 26 IAW B737-300 SRM 53-10-51 PG 213-219 FIG 204, SRM 51-40-02 PG 3 & 4 FIG 3-4, 6-8.