What was found
During "C" Check Inspection.-Fuselage, Keel Beam Panel Cracked at BS 698 and With Loose Rivets at BS726, Str27 L-H.-Replaced Fuselage Keel Beam Skin Panel from BS 661.75 to BS 726.75, Between LBL 6.30 to RBL 6.30 due to Cracks IAW Boeing S/B 737-53-1104, Section III, Part II, Fig 3, 6 & 7, Rev. 4.Note: See COOPESA Work Order No. O10863 1-10, VAM100 No. 045 & 122SDA096.