90-02-22 DEHAVILLAND: Amendment 39-6471.
Applicability: Models DHC-2 Mk. I (including L-20A, YL-20, U-6, and U-6A), and DHC-2 Mk. II (serial numbers 1 through 1056) airplanes certificated in any category.
Compliance: Required as indicated in the body of the AD.
To ensure the structural integrity of the horizontal tailplane to fuselage front attachment brackets, accomplish the following:
(a) Within the next 200 hours time-in-service (TIS), or prior to the accumulation of 1000 hours TIS, whichever occurs later after the effective date of this AD, unless already accomplished per the requirements of AD 54-11-01, and thereafter at intervals not to exceed 1000 hours TIS:
(1) Inspect attachment brackets, part number (P/N) C2-FS-543A and P/N C2-FS-544A for cracks and distorted rivets in accordance with paragraph `A' of the "ACCOMPLISHMENT INSTRUCTIONS" in deHavilland Service Bulletin (S/B) No. 2/42, Revision C, dated February 2, 1989.
(2) Prior to furtherflight replace any distorted rivets as indicated in the above S/B, paragraph "B", and any cracked brackets as indicated in paragraph "C" of the Service Bulletin.
(b) At each interval not exceeding 1000 hours TIS since the last bolt replacement, replace all 1/4 inch diameter forward attachment bolts on the tailplane front attachment brackets with new bolts, P/N AN174-H12A, in accordance with S/B No. 2/42 Rev C.
(c) The repetitive inspections or modifications in paragraph (a) of this AD are not required on airplanes modified in accordance with deHavilland Modification No. 2/1338, or Agriculture Modification No. 2/984, as applicable.
(d) Airplanes may be flown in accordance with FAR 21.197 to a location where the requirements of this AD may be accomplished.
(e) An alternate method of compliance or adjustment of the initial or repetitive compliance times, which provides an equivalent level of safety, may be used when approved by the Manager, New York Aircraft Certification Office, FAA, New England Region, 181 South Franklin Avenue, Valley Stream, New York 11581.
NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York Aircraft Certification Office.
All persons affected by this directive may obtain copies of the documents referred to herein upon request to Boeing of Canada, Ltd.; deHavilland Division, Garratt Boulevard, Downsview, Ontario, Canada M3K 1Y5; Telephone (416) 633-7310; or may examine these documents at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 East 12th Street, Kansas City, Missouri 64106.
This AD supersedes AD 54-11-01.
This amendment (39-6471, AD 90-02-22) becomes effective on February 13, 1990.