What was found
LOSS OF SYSTEM A FLUID AND PRESSURE SHORTLY AFTER LDG GEAR WAS SELECTED DN. ALL 3 GREEN DN LOCK LGTS ILLUM AND RED DR LGT REMAINED ILLUM. THE L/R GEAR DR AND TAIL SKID AMBER ANNUNCIATORS ON S/O PNL REMAINED ILLUM. FOLLOWED HYD LOSS PRO CEDURES PER POM. UNEVENTFUL FLAP 15 LDG. FOUND A SYSTEM HYD PRESSURE MODULE CHECK VALVE FAILED. FAILED VALVE ALSO DAMAGED AN A SYSTEM RETURN LINE. RPLACED PRESSURE MODULE AND INSTALLED TEMPORARY LINE.