2008-22-21: Main tubular spar

2008-22-21 Allied Ag Cat Productions, Inc.: Amendment 39-15718; Docket No. FAA-2008-0854; Directorate Identifier 2008-CE-050-AD. Effective Date (a) This AD becomes effective on December 19, 2008. Affected ADs (b) This AD supersedes AD 78-08-09, Amendment 39-3191. Applicability (c) This AD applies to the following airplane models, all serial numbers, that are certificated in any category: Models G-164, G-164A, G-164B, G-164B with 73'' wing gap, G-164B-15T, G-164B-34T, G-164B-20T, G-164C, G-164D, and G-164D with 73'' wing gap. Unsafe Condition (d) This AD results from a report of the rudder main tubular spar failing on a later production airplane. We are issuing this AD to detect and correct corrosion in the rudder main tubular spar, which could result in failure of the weld to the main spar tube. This failure could lead to loss of directional control. Compliance (e) To address this problem, you must do the following, unless already done: Actions Compliance Procedures (1) Drill an access hole and do a visual inspection using a borescope of the lower end internal cavity of the rudder main spar tube for corrosion and do a visual inspection of the exterior of the rudder main spar tube for corrosion. (i) For airplanes previously affected by AD 78-08-09: Initially inspect within the next 60 months after the last inspection required in AD 78-08-09 or within the next 30 days after December 19, 2008 (the effective date of this AD), whichever occurs later. Repetitively inspect thereafter at intervals not to exceed 60 calendar months. (ii) For airplanes not previously affected by AD 78-08-09: Initially inspect within the next 30 days after the effective date of this AD. Repetitively inspect thereafter at intervals not to exceed 60 calendar months. Following Steps 1 through 3 of Grumman American Aviation Corporation Ag-Cat Service Bulletin No. 61, dated June 6, 1977. (2) If corrosion is found during any inspection required in paragraph (e)(1) of this AD, repair in accordance with Advisory Circular 43.13-1B or equivalent, or replace the damaged part(s). Before further flight after any inspection in which corrosion is found. As specified in Steps 5 and 6 of Grumman American Aviation Corporation Ag-Cat Service Bulletin No. 61, dated June 6, 1977. Following Advisory Circular 43.13-1B or equivalent and/or an FAA-approved procedure. The appropriate maintenance manual contains these procedures. (3) After each inspection, repair, or replacement required in this AD, corrosion protect the spar tube internal cavity by filling with warm, raw linseed oil, Paralketone, or CRC3 (LPS Heavy Duty Rust Inhibitor Type 3), or suitable equivalent protector for alloy steel, and allow to drain. Seal access hole with Scotch caulking compound, a suitable silicone based sealant, or equivalent. Before further flight after any inspection required in paragraph (e)(1) of this AD and after any repair or replacementrequired in paragraph (e)(2) of this AD. As specified in Step 4 of Grumman American Aviation Corporation Ag-Cat Service Bulletin No. 61, dated June 6, 1977. (4) Verify rigging check of the rudder. Before further flight after any inspection required in paragraph (e)(1) of this AD and after any repair or replacement required in paragraph (e)(2) of this AD. Following an FAA-approved procedure. The appropriate maintenance manual contains these procedures. (5) Only install a rudder that has been inspected as specified in paragraph (e)(1) of this AD, is free of corrosion, and has had the corrosion protection applied and sealed as specified in paragraph (e)(3) of this AD. As of the next 30 days after December 19, 2008 (the effective date of this AD. Not applicable. Alternative Methods of Compliance (AMOCs) (f) The Manager, Fort Worth Airplane Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Andy McAnaul, Aerospace Engineer, ASW-150, FAA San Antonio MIDO-43, 10100 Reunion Place, Suite 650, San Antonio, Texas 78216, phone: (210) 308-3365; fax: (210) 308-3370. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. (g) AMOCs approved for AD 78-08-09 are not approved for this AD. Material Incorporated by Reference (h) You must use Grumman American Aviation Corporation Ag-Cat Service Bulletin No. 61, dated June 6, 1977, and Ag-Cat Maintenance Manual pages 6-14 through 6-16, copyright 1978; or Ag-Cat G-164D Maintenance Manual pages 6-24 and 6-29, copyright 1995, to do the actions required by this AD, unless the AD specifies otherwise. (1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. (2)For service information identified in this AD, contact Allied Ag Cat Productions, Inc., 301 West Walnut Street, P.O. Box 482, Walnut Ridge, Arkansas 72479; telephone: (870) 886-2418. (3) You may review copies at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Kansas City, Missouri 64106; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202- 741-6030, or go to: http://www.archives.gov/federal_register/code_ of_federal_regulations/ibr_locations.html.