AD 93-10-08

93-10-08 DE HAVILLAND: Amendment 39-8588. Docket No. 91-CE-49-AD. Supersedes AD 73-19-06, Amendments 39-1800 and 39-1710.

Applicability: Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 airplanes (serial numbers 1 through 420), certificated in any category.

Compliance: Required as indicated, unless already accomplished.

To prevent failure of the overhead control console, which could result in loss of control of the airplane, accomplish the following:

(a) Within the next 25 hours time-in-service (TIS) after the effective date of this AD, unless already accomplished within the last 175 hours TIS (compliance with AD 73-19-06), visually inspect the overhead console control quadrants for cracks in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland Service Bulletin (SB) 6/298, Revision D, dated December 20, 1991.

(1) If cracks are found that meet or exceed the requirements specified in paragraph 3.1 of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/298, Revision D, dated December 20, 1991, prior to further flight, replace the overhead control console quadrants, part number (P/N) C6-CE-1010, with P/N C6CE1421-27 in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/298.

(2) If cracks are found that meet or exceed the requirements specified in paragraph 3.2 of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/298, Revision D, dated December 20, 1991, within the next 200 hours TIS, replace the overhead control console quadrants, P/N C6-CE-1010, with P/N C6CE1421-27 in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/298.

(3) If cracks are found that are less than that specified in paragraph 3.2 of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/298, Revision D, dated December 20, 1991, reinspect at intervals not to exceed 100 hours TIS until the modification specified in paragraph (b) of this AD is accomplished.

(4) If no cracks are found, reinspect at intervals not to exceed 200 hours TIS until the modification specified in paragraph (b) of this AD is accomplished.

(b) Within the next 2,400 hours TIS after the effective date of this AD, unless already accomplished as specified in paragraph (a)(1) or (a)(2) of this AD, replace the overhead control console quadrants, P/N C6-CE-1010, with P/N C6CE1421-27 in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/298, Revision D, dated December 20, 1991.

(c) The installation of new overhead control console quadrants (Modification No. 6/1467) as specified in paragraphs (a)(1), (a)(2), and (b) of this AD is considered terminating action for the repetitive inspection requirement of this AD.

(d) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(e) 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, 181 Franklin Avenue, Room 202, Valley Stream, New York 11581. The request shall be forwarded through an FAA Maintenance Inspector, who may add comments and then send it to the Manager, New York Aircraft Certification Office.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York Aircraft Certification Office.

(f) The inspections and modification required by this AD shall be done in accordance with de Havilland Service Bulletin (SB) 6/298, Revision D, dated December 20, 1991. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from de Havilland, Inc., 123 Garratt Boulevard, Downsview, Ontario, Canada, M3K 1Y5. 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.

(g) This amendment (39-8588) supersedes AD 73-19-06, Amendments 39-1800 and 39-1710.

(h) This amendment becomes effective on July 16, 1993.