AD 83-09-02

83-09-02 MITSUBISHI HEAVY INDUSTRIES, LTD: Amendment 39-4647. Applies to Models MU-2B-25 and -26 (serial numbers 239 through 328; except serial numbers 313, 321, and airplanes having a serial number with the suffix "SA") and Models MU-2B-30, -35, and -36 (serial numbers 501, 504, and 548 through 673; except serial numbers 652, 661 and airplanes having a serial number with the suffix "SA") airplanes certificated in any category.

Compliance: Required as indicated, unless already accomplished.

To prevent fuel or fuel vapors from entering the wing tip strobe light assemblies, accomplish the following: (a) Within the next 100 hours time-in-service after the effective date of this AD and thereafter at intervals not to exceed 100 hours time-in-service from the last inspection, inspect the strobe light conduit tubes in the wing tip fuel tanks as detailed in MU-2 Service Bulletin No. 174C dated October 2, 1981 (hereafter referred to as the SB), Item 1 - Inspection for Leakage. Ifleaks are found, prior to further flight, modify the tip tank conduit tube in accordance with Item 2 - Rework Procedure of the SB.

(b) On or before September 1, 1983, modify the tip tank conduit tubes in accordance with Item 2 - Rework Procedure of the SB.

(c) When Item 2 - Rework Procedure of the SB is accomplished, the repetitive inspection required by paragraph (a) is no longer required.

(d) The intervals between the repetitive inspections required by this AD may be adjusted up to 10 percent of the specified interval to allow accomplishing these inspections concurrent with other scheduled maintenance of the airplane.

(e) Aircraft may be flown in accordance with Federal Aviation Regulation 21.197 to a location where this AD can be accomplished.

(f) An equivalent method of compliance with this AD, if used, must be approved by the Manager, Aircraft Certification Field Office, ANM-170H, Federal Aviation Administration, P.O. Box 50246, Honolulu, Hawaii 96850.

This AD supersedes AD 77-13-12, Amendment 39-2937. This amendment becomes effective on May 17, 1983.