What was found
DURING ROUTINE C CHECK INSPECTION, FOUND EXTERNAL FUSELAGE NOSE SECTION RIGHT AFT PRIMARY HEAT INTERCHANGER AFT LOWER CORNER DOUBLER CRACKED AT STATION -12 LONGERON 27 RIGHT. REMOVED EXISTING REPAIR. FABRICATED REPAIR DOUBLER. CLEANED TREATED AND PRIMED AREA AND REPAIR PARTS. APPLIED SEALANT TO FAYING SURFACE. INSTALLED REPAIR PARTS IAW DC8 SRM 51-1-20D, DC8 MM 53-30-09 PAGES 201, 202, 206 AND 209, DC8 SRM 51-1-8B, DC8 SRM 51-1-11,DC8 SRM 51-1-20D, AND DC8 SRM 51-3-1.