As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FRAME HAS SEVERE RUST PITTING ON FRAME TUBING BOTTOM LEFT AND RIGHT SIDES FORWARD OF WELDED CLUSTER. PITTING AREA APPROXIMATELY 1 INCH LONG ALL AROUND TUBING. CAUSE UNKNOWN, HOWEVER THIS IS INBOARD AND AFT OF FLAP AREA. NOTED CONDITION WHEN FLOOR REMOVED FOR ANNUAL AND AD 2008-09-13 FLAP TO TUBING REPAIR NEEDED. THIS AREA SHOULD BE CHECKED ON OTHER AIRCRAFT.