Airworthiness Directive · Amendment 39-21369 · Propellers
Mitsubishi Heavy Industries, Ltd. Airplanes
This AD applies to all Mitsubishi Heavy Industries, Ltd. (Mitsubishi) Models MU-2B, MU-2B-10, MU-2B-15, MU-2B-20, MU-2B-25, MU-2B-26, MU-2B-26A, MU-2B-30, MU-2B-35, MU-2B-36, MU-2B-36A, MU-2B-40, and MU-2B-60 airplanes, certificated in any category.
The FAA is superseding Airworthiness Directive (AD) 75-16-20, which applied to all Mitsubishi Heavy Industries, Ltd., Model MU-2B, MU-2B-10, MU-2B-15, MU-2B-20, MU-2B-25, MU-2B-26, MU-2B-30, MU-2B-35, and MU-2B-36 airplanes. AD 75-16-20 required repetitive inspections of the propeller pitch control (PPC) lever for security and proper rigging. This AD requires modification and repetitive inspections of the PPC lever linkage. The FAA is issuing this AD to address the unsafe condition on these products.
(1) For all airplanes except Model MU-2B and MU-2B-10 airplanes: Within 100 hours time-in-service (TIS) after the effective date of this AD or within 12 months after the effective date of this AD, whichever occurs first, modify the PPC lever linkage as specified in paragraphs (g)(1)(i) through (iii) of this AD, as applicable.
(i) Replace the PPC lever clamping bolt in accordance with the Accomplishment Instructions, section 2, of Mitsubishi MU-2 Service Bulletin No. 106/76-004, dated February 24, 2016, or Mitsubishi MU-2 Service Bulletin No. 244, dated December 25, 2015, as applicable to your model airplane.
(ii) For airplanes without a threaded hole in the splined end of the shouldered shaft of the PPC assembly, incorporate a threaded hole in accordance with the Accomplishment Instructions, paragraph 3.C.(3)(d) 2, of Honeywell International Inc. Service Bulletin TPE331-72-2190, Revision 0, dated December 21, 2011.
(iii) Install a secondary retention feature in the threaded end of the PPC input shaft in accordance with the Accomplishment Instructions, section 2, of Mitsubishi MU-2 Service Recommendation No. 049/76-002, dated June 29, 2018, or Mitsubishi MU-2 Service Recommendation No. 080, dated June 29, 2018, as applicable to your model airplane.
(2) For Model MU-2B and MU-2B-10 airplanes: Within 100 hours TIS after the effective date of this AD or within 12 months after the effective date of this AD, whichever occurs first, replace the PPC lever clamping bolt and install a secondary retention feature in the threaded end of the PPC input shaft using a method approved by the Manager of the Fort Worth ACO Branch, FAA. The Manager's approval letter must specifically refer to this AD.
Within 100 hours TIS after replacing the bolt and installing a secondary retention feature as required by paragraph (g) of this AD and thereafter at intervals not to exceed 100 hours TIS, inspect the security of the PPC lever by pulling the PPC lever upward by hand to ensure it does not detach from the PPC input shaft. If the PPC lever detaches, do the following.
(1) Before further flight, install the PPC lever using a method approved by the Manager of the Fort Worth ACO Branch, FAA. The Manager's approval letter must specifically refer to this AD.
(2) Within 30 days after the PPC lever detachment or within 30 days after the effective date of this AD, whichever occurs later, report the results of the inspection, including airplane model and serial number, to the FAA representative identified in paragraph (l)(2) of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
