97-07-10 R1 DEHAVILLAND: Amendment 39-10016; Docket No. 93-CE-45-AD. Revises AD 97-07-10, Amendment 39-9984.
Applicability: Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 airplanes (all serial numbers), certificated in any category, that do not have Modification No. 6/1581 incorporated.
NOTE 1: Modification No. 6/1581 consists of installing a preformed nylon shield around the area of each wing strut at the upper end closest to the wing.
NOTE 2: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless already accomplished.
To prevent failure of the wing struts, which could result in loss of control of the airplane, accomplish the following:
(a) Within the next 100 hours time-in-service (TIS) after the effective date of this AD, inspect the wing struts, part number (P/N) C6W1005 (or FAA-approved equivalent), for cracks or damage (chafing, etc.) in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland Service Bulletin (SB) No. 6/342, dated February 23, 1976.
(1) If damage is found on a wing strut that exceeds 0.025-inch in depth, exceeds a total length of 5 inches, or where any two places of damage are separated by less than 10 inches of undamaged surface over the length of the strut, prior to further flight, replace the wing strut with an airworthy FAA-approved part in accordance with the applicable maintenance manual.
(2) If any crack is found, prior to further flight, replace the wing strut with an airworthy FAA-approved part in accordance with the applicable maintenance manual.
(3) If damage is found on a wing strut that exceeds 0.010-inch in depth, provided the damage does not exceed 0.025-inch in depth, the damage does not exceed a total length of 5 inches, and where any two places of damage are separated by a minimum of 10 inches undamaged surface over the length of the strut, within 500 hours TIS after the inspection specified in paragraph (a) of this AD, replace the wing strut with an airworthy FAA-approved part in accordance with the applicable maintenance manual.
(b) Within the next 600 hours TIS after the effective date of this AD, incorporate Modification No. 6/1581 in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/342, dated February 23, 1976. Incorporating Modification No. 6/1581 may be accomplished at any time prior to 600 hours TIS after the effective date of this AD, at which time it must be incorporated.
(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.
(d) An alternative method of compliance or adjustment of the compliance times that provides an equivalent level of safety may be approved by the Manager, New York Aircraft Certification Office (ACO), FAA, 10 Fifth Street, 3rd Floor, Valley Stream, New York 11581. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.
NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from theNew York ACO.
(e) The inspections and modification required by this AD shall be done in accordance with de Havilland Service Bulletin No. 6/342, dated February 23, 1976. This incorporation by reference was approved previously by the Director of the Federal Register, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as of April 1, 1997 (62 FR 15373, April 1, 1997). Copies may be obtained from de Havilland, Inc., 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5 Canada. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(f) This amendment becomes effective on May 23, 1997.