AD 80-13-11 R2 ACTIVE

80-13-11 R2 DeHAVILLAND: Amendment 39-3814 as amended by Amendment 39-4703. Applies to all DHC-6 model airplanes, certificated in all categories.

To prevent possible loss of control due to cracking of the elevator, flap and aileron control rods, accomplish the following:

(a) On aircraft Serial Numbers 1 thru 430 and on those aircraft having as replacement control rods those with part numbers listed in Column 2 of Table 2 in DeHavilland Service Bulletin 6/390, within the next 50 hours in service or 30 days, whichever occurs first, after the effective date of this AD, unless previously accomplished within the last 350 hours in service or 150 days, whichever occurred last, visually inspect tube ends of the rod assemblies in accordance with the dye penetrant method using at least a ten power glass, in the above Bulletin's paragraph 8, 9 and 10 of ACCOMPLISHMENT INSTRUCTIONS, or approved equivalent.

(b) If cracks are not or have not been found, repeat inspection in paragraph (a) within 400 hours in service or 180 days, whichever occurs first after the last inspection. Following inspection, install sleeves on rods in accordance with the above Bulletin's ACCOMPLISHMENT INSTRUCTIONS or approved equivalent and the applicable drawings and Mod numbers listed in Column 4 of Table 1.

(c) On aircraft Serial Numbers 431 thru 685 and on other aircraft having as replacement control rods those with part numbers listed as "original" in Column 5 of Table 2 in the above Bulletin, within 800 hours in service or one year, whichever occurs first, from the effective date of this AD, unless previously accomplished, inspect in accordance with paragraph (a). Following inspection, install sleeves on rods in accordance with the Bulletin's ACCOMPLISHMENT INSTRUCTIONS or approved equivalent and the applicable drawings and Mod numbers listed in Column 5 of Table 1.

(d) On aircraft Serial Numbers 686 and subsequent and all other aircraft on which paragraphs (b) or (c) have been accomplished:

(1) Remove external paint and visually inspect with at least a ten power glass in accordance with the above Service Bulletin those areas shown in Figure 1 on all tube ends of the rod assemblies listed in Column 4 or 5 of Table 2 of the Bulletin.

(2) The inspections specified in paragraph (d)(1) of this AD must be accomplished at intervals not to exceed 800 hours time-in-service, or 1 year, whichever occurs first, from the last inspection.

(e) If cracks are found, the rod assembly must be replaced before further flight with rods of the same part number or equivalent inspected and found serviceable in accordance with paragraph (a); or with new rods of the same part number or equivalent; or with new Post-Mod rods whose parts are listed in Column 5 or 6 of Table 1 in the above Bulletin.

(f) Report positive findings, including crack length, from any of the above inspections to the Manager, Aircraft Certification Office, FAA, New England Region, within 10 days of inspection. (Reporting approved by Office of Management and Budget under OMB No. 04-R0174.)

(g) Equivalent parts and procedures must be approved by the Manager, Aircraft Certification Office, FAA, New England Region.

(h) Compliance times may be increased by the Manager, Aircraft Certification Office, FAA, New England Region, upon receipt of substantiating data submitted through an FAA Maintenance Inspector.

Amendment 39-3814 was effective July 1, 1980.

This Amendment 39-4703 becomes effective August 10, 1983.