As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
*****MAJOR*****WHILE AC WAS IN FOR HEAVY CHECK FOUND CRACK ON RT WING LOWER SKIN AT RIB 17 BTW SPAR 1 AND STR 19. MX REPAIRED SKIN BY REMOVING CRACKED AREA AND INSTALLING A DOUBLER TO SKIN, PN AFFECTED 170-01424-004. IAW ETD2018-170-134377. FOR DETAILS OF WORK PERFORMED SEE WORK CARD 0018. *****MAJOR*****