Flight Control System

FAA Aviation Safety SPECIAL AIRWORTHINESS INFORMATION BULLETIN SAIB: CE-11-29R1 SUBJ: Flight Control System Date: September 27, 2011 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin (SAIB) informs registered owners/operators of Cessna Aircraft Company (Cessna) 414A and 421C aircraft with S-TEC Corporation (S-TEC) Supplemental Type Certificate (STC) SA08996AC-D (system 55/55X) with optional Trim installed, Cessna 414A and 421C aircraft with S-TEC STC SA7787SW-D (system 65) with optional Trim installed, and Cessna 414A and 421C aircraft with S-TEC STC SA7790SW-D (system 60) with optional Trim installed, of an airworthiness concern. Specifically, this SAIB provides guidance on procedures for inspection of the rudder trim tab blocks which were relocated during the installation of the STC. This SAIB also provides guidance on inspecting phenolic blocks for wear along the flight control system.

At this time, this airworthiness concern has not been determined to be an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.

This SAIB has been revised to incorporate the changes to S-TEC Service Bulletin (SB) 11-001, removes the reference that Cessna may take similar action, and notifies operators that STCs SA08996AC-D, SA7787SW-D, and SA7790SW-D have been revised to incorporate the changes recommended in this SAIB.

Background

During an inspection of an elevator trim installation per S-TEC STC SA08996AC-D, it was found that the elevator trim cables pass through a bulkhead with about five degrees of deflection. A phenolic block is installed to prevent wear on the bulkhead and cable. Additionally, the cable impacts the floor aft of the bulkhead. A phenolic strip is installed to prevent contact between the cable and the floor. Until recently, there were no directed inspections of the phenolic block and strip.

The S-TEC STCs have been revised to install pulleys to move the cables off the bulkhead pass through.

Also, during the installation inspection, it was noticed that the rudder trim tab blocks were not properly relocated in accordance with the S-TEC STCs. This prevented the rudder system from obtaining full travel. There was no approval for the location and installation of the trim tab blocks for this particular installation.

Recommendations

The Federal Aviation Administration (FAA) recommends you inspect your rudder trim tab blocks and flight control cables in accordance with S-TEC Service Bulletin (SB) 11-001R2, dated June 28, 2011. If during the inspections listed in the SB, it is determined that the rudder trim tab blocks were not relocated in accordance with the STC, they must be relocated in accordance with the 1

2 STC as reflected in paragraph 3 of SB 11-001R2 or any other method which is approved by the FAA. The FAA also recommends you modify your installation to include the changes made in the updated STC which include the installation of the pulleys to move the cables off the bulkhead pass through.

For Further Information Contact

Garry Sills, Aerospace Engineer, 2601 Meacham Boulevard, Fort Worth, TX 76137; phone: (817) 222-5154; fax: (817) 222-5960; e-mail: [email protected].

For Related Service Information Contact

S-TEC Corporation, One S-TEC Way, Municipal Airport, Mineral Wells, TX, 76067; phone: (800) 872-7832; fax: (940) 325-3904; website: www.s-tec.com