93-02-04 DE HAVILLAND: Amendment 39-8486. Docket No. 91-CE-48-AD. Supersedes AD 77-03-07, Amendment 39-3100.
Applicability: Model DHC-6-1/100/200/300 airplanes (serial numbers 2 through 494, 497 through 503, 505, and 507), certificated in any category, that have not incorporated Modification 6/1594 in accordance with Part C of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland Service Bulletin (SB) 6/348, which incorporates the following pages:
Pages
Revision Level
Date
5-8, 13-16, and 23-25
Original
July 16, 1976
9-12, and 17-22
Revision A
August 30, 1976
1-4
Revision C
July 15, 1977
Compliance: Required as indicated after the effective date of this AD, unless already accomplished.
To prevent failure of the elevator support assembly, which could result in loss of control of the airplane, accomplish the following:
(a) Within the next 25 hours time-in-service (TIS), unless already accomplished within the last 175 hours TIS, and thereafter at intervals not to exceed 200 hours TIS until Modification No. 6/1594 is incorporated as specified in paragraph (b) of this AD, accomplish the following:
(1) Visually inspect the floor structure channel members, part numbers C6FS1229-37 and C6FS1229-31, for cracks in the area around the lower pivot bearing housing in accordance with the instructions in Part A of de Havilland SB No. 6/348. If cracks are found, prior to further flight, repair or replace any cracked components in accordance with Part B or C of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/348.
(2) Visually inspect the top and bottom flanges of the hydraulic hand pump fitting, part number C6FSM1293-27, for cracks immediately behind the front bolt boss in accordance with Part A of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/348. If cracks are found, prior to further flight, repair or replace in accordance with Part B or C of the instructions in de Havilland SB No. 6/348.
(3) If the replacement requirements of paragraphs (a)(1) and (a)(2) of this AD are accomplished in accordance with Part C of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 6/348, then the inspection requirements of this AD are no longer required.
(b) Within the next 2,400 hours TIS, unless already accomplished as specified in paragraph (a)(3) of this AD, incorporate Modification 6/1594 in accordance with Part C of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB 6/348. This modification is considered terminating action for the inspection requirements of this AD.
(c) 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.
(d) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, New York Aircraft Certification Office, FAA, 181 South Franklin Avenue, Room 202, 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 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.
(e) The inspections and modification required by this AD shall be done in accordance with de Havilland Service Bulletin 6/348, which consists of the following effective pages:
Pages
Revision Level
Date
5-8, 13-16,
and 23-25
Original
July 16, 1976
9-12, and
17-22
Revision A
August 30, 1976
1-4
Revision C
July 15, 1977
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 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 (39-8486) supersedes AD 77-03-07, Amendment 39-3100.
(g) This amendment becomes effective on March 19, 1993.