92-20-01 DE HAVILLAND, INC.: Amendment 39-8375. Docket No. 92-NM-55-AD.
Applicability: Model DHC-7 airplanes; on which stainless steel cables, Post- Modification Number 7/2609, have not been installed; certificated in any category.
Compliance: Required as indicated, unless accomplished previously.
To prevent a gear-up landing, accomplish the following:
(a) Within 30 days after the effective date of this AD, perform a detailed inspection of the left- and right-hand main landing gear (MLG) emergency down release cables to detect corrosion, in accordance with de Havilland Alert Service Bulletin A7-32-94, dated September 3, 1991; or Revision A, dated November 15, 1991.
(b) If any corrosion is detected as a result of the inspection required by paragraph (a) of this AD, prior to further flight, replace both cable assemblies with either stainless steel cables (Post-Modification Number 7/2609) or carbon steel cables (Pre-Modification 7/2609), in accordance with de Havilland Alert Service Bulletin A7-32-94, dated September 3, 1991; or Revision A, dated November 15, 1991.
(c) Within 6 months after the effective date of this AD, or within 12 months after installing carbon steel cables, if installed in accordance with paragraph (b) of this AD: Install Post-Modification 7/2609 cables, in accordance with de Havilland Alert Service Bulletin A7-32-94, dated September 3, 1991; or Revision A, dated November 15, 1991.
(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.
NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.
(e) 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.
(f) The inspection, replacement, and installation shall be done in accordance with de Havilland Alert Service Bulletin A7-32-94, dated September 3, 1991; or Revision A, dated November 15, 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., Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New England Region, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(g) This amendment becomes effective on November 17, 1992.