88-13-01 MITSUBISHI: Amendment 39-5951. Applies to Model MU-2B, MU-2B-10, - 15, -20, -25, -26, -26A, -30, -35, -36, -36A, -40, and -60 (all serial numbers, with or without the SA suffix) airplanes certificated in any category, equipped with Bendix M-4C or M-4D autopilots and/or Bendix electric pitch trim systems.
NOTE 1: The serial number of airplanes manufactured in the United States by Mitsubishi (MAI) under TC A10SW are suffixed by "SA." The serial numbers of airplanes manufactured in Japan by Mitsubishi Heavy Industries, Inc. (MHI) under TC A2PC have no suffix.
Compliance: Required within the next 200 flight hours or five (5) calendar months, whichever occurs first, unless already accomplished.
To minimize the possibility of confusion in autopilot/manual electric pitch trim disconnect/interrupt switch location, accomplish the following:
(a) Modify the control yoke in the affected model and serial numbered airplanes as follows:
(1) For MU-2B-30 and -35 model airplanes manufactured under TC A2PC equipped with a Japanese Civil Airworthiness Board (JCAB) approved Bendix M-4C autopilot, in accordance with MHI Service Bulletin (S/B) No. 206 dated October 13, 1987, or
(2) For all other MU-2B model airplanes equipped with an FAA approved installation of the Bendix M-4C or M-4D autopilots, in accordance with MHI S/B No. 066/22- 006, dated December 18, 1987.
(b) For MU-2B-35 and -36 model airplanes with Bendix autopilots installed in accordance with STC SA1693SW and MU-2B-35, -36A, and -60 model airplanes with Bendix M-4D autopilots installed in accordance with approved MAI data, accomplish the following:
(1) Insert additional placard data in the LIMITATION section of the Airplane Flight Manual Supplement (AFMS) as follows:
"COUPLED AUTOPILOT APPROACHES BELOW 125 KCAS OR 300 FEET AGL NOT PERMITTED."
(2) Fabricate and install a permanent red colored placard in full view of the pilot using white colored letters of a minimum of 0.10 inches in height which state:
"COUPLED AUTOPILOT APPROACHES BELOW 125 KCAS OR 300 FEET AGL NOT PERMITTED."
(c) Insertion of a copy of this AD in the LIMITATIONS section of the AFMS satisfies the requirements of paragraph (b)(1) of this AD.
(d) Prior to returning the aircraft to service, accomplish a visual configuration check and system functional ground test, and record successful completion in the appropriate airplane maintenance record as prescribed by FAR 91.173, as follows:
(1) Visually verify that:
(i) The disconnect/interrupt switch is red in color and located on the outboard horn of the control wheel; and,
(ii) The disconnect/interrupt switch is properly labeled as shown in Figure 7 of the MHI S/B No. 206 for A2PC airplanes or as shown in Figure 8 or Figure 9, (as appropriate for the control wheel configuration) of MHI S/B No. 066/22-006 for A10SW airplanes, as applicable; and,
(iii) The autopilot circuit breaker is properly labeled.
(2) If a manual electric pitch trim system is installed with or without an autopilot system, engage the system and press the trim button to cause the manual pitch trim wheel to rotate, then verify that after each of the following operations is performed the manual pitch trim wheel stops moving when:
(i) The disconnect/interrupt switch is depressed;
(ii) The Master Electric Power switch is positioned to "OFF;"
(iii) The Radio Master switch is positioned to "OFF" (if installed and so configured),
(iv) The electric trim circuit breaker is pulled. (On some MU-2B airplanes without an electric trim circuit breaker, the autopilot circuit breaker/switch is used to disconnect the system in lieu of the electric trim circuit breaker.)
NOTE 2: It is very important to verify that the manual pitch trim wheel stops moving after each of the above operations.
(3) If an autopilot system is installed, with or without a manual electric trim system, engage the system and then verify:
(i) That the autopilot system canbe overpowered by pushing or pulling on the control yoke; and,
(ii) That, while overpowering the autopilot, the manual pitch trim wheel stops moving when each of the following operations is performed:
(A) The disconnect/interrupt switch is depressed;
(B) The autopilot master switch is positioned to "OFF" (On some MU-2B airplanes not equipped with an autopilot master switch beside the controller, the radio master switch must be used to disconnect the system in lieu of the autopilot master switch);
(C) The autopilot circuit breaker is pulled.
NOTE 3: It is very important that the manual pitch trim wheel stops moving after each of these operations.
(e) Airplanes may be flown in accordance with FAR 21.197 to a location where this AD may be accomplished.
(f) An equivalent method of compliance with this AD may be used on the MHI airplanes, if approved by the Manager, Western Aircraft Certification Office, ANM-170W, FAA, P.O. Box 92007, Worldway Postal Center, Los Angeles, California 90009-2003; and on the MAI airplanes, if approved by the Manager, Wichita Aircraft Certification Office, ACE-115W, FAA, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209.
All persons affected by this directive may obtain copies of the documents referred to herein upon request to Beech Aircraft Corporation (Licensee to Mitsubishi), P.O. Box 85, Wichita, Kansas 67201; Telephone (316) 681-7279; or may examine the documents referred to herein at FAA, Office of the Regional Counsel, Room 1558, 601 East 12th Street, Kansas City, Missouri 64106.
This amendment, 39-5951, becomes effective on July 11, 1988.