As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE BS 1342, RT LOWER FRAME CHORD WAS FOUND SEVERELY RUSTED DURING A RE-ENGINING MODIFICATION. THIS CONDITION HAS BEEN DISCOVERED ON ALL 38 A/C MODIFIED THUS FAR. THE CONDITION IS PROBABLY CAUSED BY DISSIMILAR METALS AND LACK OF DRAINAGE. NOTE: THE RUST CANNOT BE SEEN WITHOUT REMOVING THE PART, SO IT MAY NEED AN X-RAY INSPECTION EVERY SO MANY YEARS.