AD 2005-16-03 Airworthiness Directives; Bombardier Model DHC-7-100, DHC-7-101, DHC-7-102, and DHC-7-103 Airplanes

Models named: DHC-7-100, DHC-7-101, DHC-7-102, DHC-7-103. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Bombardier Model DHC-7-100, DHC-7-101, DHC-7-102, and DHC-7-103 airplanes, serial numbers 3 through 10 inclusive, 12 through 14 inclusive, and 16 through 27 inclusive; certificated in any category. Note 1: This AD requires revision to a certain operator maintenance document to include a new replacement time. Compliance with this replacement time is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by this replacement time, the operator may not be able to accomplish the replacement described in the revision. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (i) of this AD. The request should include a description of changes to the required replacement time that will ensure the continued damage tolerance of the affected structure. The FAA has provided guidance for this determination in Advisory Circular (AC) 25-1529.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Revise the Airworthiness Limitations (AWL) Section—New Life Limit (f) Within 30 days after the effective date of this AD, revise the AWL section of the Instructions for Continued Airworthiness to incorporate new life limits for the lower wing skins by incorporating Bombardier Temporary Revision (TR) 5-103, dated March 26, 2004, to the Bombardier Dash 7 Series 100 Maintenance Manual, PSM 1-7-2, into the AWL section. (g) When the contents of Bombardier TR 5-103, dated March 26, 2004, have been included in the general revisions of the AWL section, the general revisions may be incorporated into the AWL section, and the TR may be removed from the AWL section. (h) After the actions specified in paragraphs (f) and (g) of this AD have been accomplished, no alternative life limits may be approved for the lower wing skins, except as provided in paragraph (i) of this AD. Alternative Methods of Compliance (AMOCs) (i) The Manager, New York Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. Related Information (j) Canadian airworthiness directive CF-2004-12, dated June 28, 2004, also addresses the subject of this AD. Material Incorporated by Reference (k) You must use Bombardier Temporary Revision 5-103 to Chapter 5-10-11 of the Bombardier Dash 7 Series 100 Maintenance Manual, PSM 1-7-2, dated March 26, 2004, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., Room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov ; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html . Issued in Renton, Washington, on July 21, 2005. Kevin M. Mullin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05-15012 Filed 8-1-05; 8:45 am] BILLING CODE 4910-13-P

This AD is prompted by the discovery that, during the manufacture of the lower wing skins, score marks may have been accidentally inscribed around the edge of the lower wing skin doublers. We are issuing this AD to prevent fatigue cracks from developing at the score marks in the lower wing skins, which could result in the structural failure of the wing.