What was found
R/H HORIZONTAL STABILIZER LOWER SKIN HAS A CRACK INDICATION LOCATED AT STAB. STA. 147.90, 8" FWD OF THE REAR SPAR. APPROX. 1.2" IN LENGTH. (AS MARKED). GROUNDED - YES. REMOVED R/H HORZ. STAB LEADING EDGE AND HORZ. STAB TIP, REMOVED EXISTING DOUBLER IAW B737-800-SRM-51-40-02, FABRICATED NEW DOUBLER, APPLIED FINISH AND REINSTALLEFD ON LEADING EDGE IAW B-737-800-SRM-55-10-01-2R-11 AND B737-800-SRM-51-40-02. REINSTALLED LEADING EDGE & TIP IAW B-737-800-AMM-27-44-21-400-801 AND B-737--800-SRM-51-40-02. THIS IS A CAT "B" REPAIR WITH 56,000 FLIGHT CYCLES THRESHOLD AND 9,000CYCLES INTERVALS