AL 2003-09
28 November 2003
Transport Canada has recently received a report of the cracking of the flap control arm, P/N C3CF170-9. The 18mm / 0.7-inch crack, running lengthwise from the threaded end of the rod, was discovered on a routine inspection.
The DHC-3 inspection requirements for this area are covered in AMM Appendix IV, P4-12, item 27, with the requirement to "Inspect" push rods for wear, damage, and security. "Inspect" is defined within this document as a visual inspection with no tool other than a flashlight and mirror.
As the failure of this part would in all likelihood result in an asymmetric flap condition, Transport Canada strongly recommends a "detailed visual" inspection be carried out, at the operator's earliest convenience, with the aid of a 10x magnifying glass to determine the integrity of this component during inspection.
Similar defects or further occurrences of this nature are to be reported to Transport Canada, Continuing Airworthiness, Ottawa, via the Service Difficulty Reporting program.
For further information contact a Transport Canada Center, or Mr. Paul Jones, Continuing Airworthiness, Ottawa, telephone (613) 952-4431, facsimile (613) 996-9178 or e-mail jonesp@tc.gc.ca.
For Director, Aircraft Certification
B. Goyaniuk
Chief, Continuing Airworthiness