De Havilland DHC-3 - Service Difficulty Alert

AL 2000-02
1 March 2000

Worn Elevator Trim Push-Pull Rods

Transport Canada has recently received 5 service difficulty reports of elevator servo tab push-pull rod wear. During inspection, it has been found that the push-pull rod (P/N C3CF418-7) for the elevator servo tab was severely worn where it runs through the bulkhead at FS 427 and rides on the roller assembly. Once the rod had been removed and inspected, the submitter discovered the rollers had worn the rod completely through.

The Periodic Inspection Document does not specifically mention this control rod, however Temporary Revision #12, Appendix 4, Part 3, Paragraph 7(a) instructs to inspect the elevator servo tab connecting rod for condition. Illustrated Parts Catalog Figure 45, Item 33 identifies the affected parts. This area is difficult to inspect.

Transport Canada strongly recommends repositioning or removing the rod to ensure that all areas in contact with the rollers are inspected. If left undetected, rod failure could result, possibly resulting in jamming or uncontrolled movement of the servo tab.

For further information contact a Transport Canada Centre, or Mr.  Steve Dudka, Continuing Airworthiness, Ottawa, telephone (613)  952--4361, facsimile  613)  996-9178  or e-mail

For Director, National Aircraft Certification

B. Goyaniuk
Chief, Continuing Airworthiness