What was found
WHILE A/C WAS IN FOR HEAVY CHECK FOUND RT WING RIB 10 EXTENTION CRACKED .75" AT 3RD HI-LOK FROM SPAR 3 ON TOP FLANGE. MX REMOVED AND REPLACED RT WING RIB 10 EXTENSION IAW EMB 170/175 SRM 51-40-01, 51-43-01, 51-40-02, 51-43-03, 51-43-04. P/N 170-32161-012. A/C REMAINS IN FOR HEAVY CHECK COMPLETION.