88-21-01 R1 MITSUBISHI: Amendment 39-6040 as amended by Amendment 39-6096.
Applicability: 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 any manual electric pitch trim system and/or any autopilot other than Bendix.
NOTE 1: The serial number of airplanes assembled in the United States by Mitsubishi Aircraft Industries (MAI) under Type Certificate (TC) A101SW 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: Within the next 200 flight hours or five (5) calendar months, whichever occurs first, unless already accomplished per the original version of this AD.
To minimize the possibility of confusion in autopilot/manual electric pitch trim disconnect/interrupt switch location and function, accomplish the following:(a) Modify the control yoke in the affected model airplanes as follows:
(1) For MU-2B-35 Model airplanes equipped with a King KFC 300 Automatic Flight Control System (AFCS) and a Sperry Manual/Electric Pitch Trim System, in accordance with Bendix/King Certification Bulletin No. CB10, KPN 006-0712-00, no revision, or
(2) For MU-2B-36 Model Airplanes equipped with a Sperry SPZ-200 AFCS and a MAI Manual/Electric Pitch Trim System, in accordance with MHI Kit - Sperry SPZ-200AP Disengagement Drawing, 035A-985006, no revision.
(b) Prior to returning the airplane to service, accomplish a visual configuration check and a system functional ground test on all MU-2B, MU-2B-10, -15, -20, -25, -26, -26A, -30, -35, -36, -36A, -40, and -60 airplanes, except those airplanes which have complied with AD 88-13-01, dated June 8, 1988, as follows:
(1) Visually verify that:
(i) The autopilot disconnect and trim disconnect/interrupt functions are combined on one button mounted on the outboard control wheel grip, and is so oriented that it is easily activated by the pilot/copilot.
(ii) The autopilot disconnect and trim disconnect/interrupt button is properly and legibly labeled to indicate functions.
(iii) The button is red in color.
(iv) There are no other red buttons nearby that could be mistaken for the autopilot disconnect.
(v) The autopilot circuit breaker is properly labeled.
(2) Perform an operational check of the autopilot disconnect and trim disconnect/interrupt button to confirm its correct functioning by disconnecting/interrupting the autopilot and the trim systems, as follows:
(i) With the manual electric pitch trim system armed, 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:
(A) The disconnect/interrupt switch is fully depressed;
(B) The master electric power switch is positioned to "OFF";
(C) The radio master switch is positioned to "OFF" (if installed and so configured); (not applicable to MU-2B airplanes equipped with Sperry SPZ-500 autopilots);
(D) 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 of paragraph (b)(2)(i).
(ii) With the autopilot system engaged, verify:
(A) That the autopilot system can be overpowered by pushing or pulling on the control yoke; and,
(B) That, while overpowering the autopilot, the manual pitch trim wheel stops moving and the autopilot disconnects when each of the following operations is performed:
(I) The disconnect/interrupt switch is depressed;
(II)The autopilot master switch or the radio master switch or the engage/disengage switch on the autopilot controller (as appropriate), 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.);
On MU-2B airplanes equipped with Sperry SPZ-500 autopilot:
(aa) the master electric power switch is positioned to "OFF";
(bb) the "GA" go-around switch on the left power lever is depressed;
(III) 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.
(3) If the result of any one of the above visual verifications or operational checks are not as specified, prior to further flight contact the Manager, Wichita Aircraft Certification Office, ACE-115W FAA, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4400, for disposition of the discrepancy.
(c) In addition to the maintenance record entry required by FAR 91.173, enter a statement showing successful completion of paragraph (b) of this AD listing the autopilot land or manual electric trim system installed.
(d) Airplanes may be flown in accordance with FAR 21.197 to a location where this AD may be accomplished.
(e) An equivalent method of compliance with this AD may be used 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 at the FAA, Office of the Assistant Chief Counsel, Room 1558, 601 East 12th Street, Kansas City, Missouri 64106.This amendment revises AD 88-21-01, Amendment 39-6040, which was effective November 6, 1988.
This amendment (39-6096, AD 88-21-01 R1) becomes effective on January 28, 1989.