SPECIAL AIRWORTHINESS INFORMATION BULLETIN SAIB: CE-10-48

FAA Aviation Safety SPECIAL AIRWORTHINESS INFORMATION BULLETIN SAIB: CE-10-48 SUBJ: Landing Gear – Main Landing Gear Date: September 8, 2010 This is information only. Recommendations aren’t mandatory. Introduction This Special Airworthiness Information Bulletin informs owners, operators, and maintenance personnel of Cessna Model 402C airplanes of caution statements that will be added to the aircraft maintenance manual. These caution statements address making sure the correct washers are tagged during removal to ensure proper location at reinstallation and to make sure the same washers are properly located under the bolt head and nut when re-connecting the torque links. At this time, the airworthiness concern is not an unsafe condition that would warrant Airworthiness Directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39. Background A Cessna Model 402C airplane recently veered off a runway upon landing. The loss of control was due to the right main landing gear (MLG) torque links detaching at a center pivot point. The detachment of the torque links allowed the lower strut and wheel assembly to rotate 90 degrees perpendicular to the runway, which caused the tire and wheel assembly to lock-up. The locking up and dragging of the tire and wheel assembly during landing inhibited the controllability of the aircraft and caused it to veer off the runway into the grass, where it came to rest. Upon investigation, it was discovered that the cause of the detachment of the right MLG torque links at the center pivot point was due to the incorrect assembly of the torque link center pivot attaching hardware, washer part number (P/N) 5045018. The intended installation of these washers is under the head of the torque link center attachment bolt and under the corresponding nut. Therefore, caution notes are being added to the Cessna 402C Maintenance Manual to stress the criticality of the correct P/N and washer configuration during assembly. Cessna will revise the Cessna 402C Maintenance Manual (P/N D2527-10-13(AF)) with the following two caution notes: Currently, the Model 402C Maintenance Manual reads, in 32-10-00, page 405, step 4, A, (2): “(a) Disconnect torque links at apex by removing cotter pin, washer, clamp (13), spacer (35) and bolt. WARNING: ENSURE ALL AIR IS EXPELLED FROM STRUT ASSEMBLY BEFORE PROCEEDING TO THE NEXT STEP.” Cessna will add, after the “warning” statement above, the following: “CAUTION: Washers, P/N 5045018-2, should be tagged during removal to ensure proper location at reinstallation.” Likewise, 32-10-00, page 410, step 4, B, (13) currently reads: 1 2 “(13) Connect torque links (12 and 17) with bolt, washers, spacer (35), clamp (13), and nut. Torque nut standard torque value and install cotter pin. NOTE: Install AN 960-716…” Cessna will add, after the “Note” above, the following from the Model 402/A/B Service Manual: “CAUTION: Washers, P/N 5045018-2, must be properly located under the bolt head and the nut.” It is expected that the revision of the manual containing these caution notes will be released in Quarter 3 of Year 2011. Recommendations The FAA recommends that the caution statements in this SAIB are used on Cessna Model 402C airplanes as a supplement to the maintenance manuals, until the revision of the manual containing these caution notes is released. For Further Information Contact Ann Johnson, Aerospace Engineer, 1801 Airport Rd., Wichita, KS 67209; phone: (316) 946-4105; fax: (316) 946-4107; e-mail: ann.johnson@faa.gov. For Related Service Information Contact Cessna Aircraft Company, Product Support, PO Box 7706, Wichita, KS 67277; phone: (316) 517- 5800; fax: (316) 517-7271.