AD/MU-2/43 - Autopilot/Electric Trim Switch Standardisation (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

Mitsubishi MU-2 Series Aeroplanes

AD/MU-2/43 Autopilot/Electric Trim Switch Standardisation 13/89

Applicability: All models fitted with Bendix model M-4C or M-4D autopilots and/or Bendix electric trim system.

Requirement: 1a. For MU 2B-30 and -35 model aeroplanes manufactured under TC A2PC equipped with a Japanese Civil Airworthiness Board (JCAB) approved Bendix M-4C autopilot; action in accordance with MHI Service Bulletin No 206.

1b. For all other MU 2B model aeroplanes equipped with an FAA approved installation of the Bendix M-4C or M-4D autopilots; action in accordance with MHI SB No 066/22-006.

2. For MU 2B-35 and -36 model aeroplanes with Bendix autopilots installed in accordance with STC SA1693SW and MU 2B-35, -36A, and -60 model aeroplanes with Bendix M-4D autopilots installed in accordance with approved MAI data, fabricate and install a permanent red coloured placard in full view of the pilot using white coloured letters of a minimum of 0.10 inches in height which state:

"COUPLED AUTOPILOT APPROACHES BELOW 125 KIAS OR 300 FEET AGL NOT PERMITTED."

Note 1: FAA AD 88-13-01 and JCAB AD TCD 2856-87 refer.

Note 2: The serial number of aeroplanes manufactured in the United States by Mitsubishi (MAI) under TC A10SW are suffixed by "SA". The serial numbers of aeroplanes manufactured in Japan by Mitsubishi Heavy Industries, Inc (MHI) under TC A2PC have no suffix.

Compliance: Prior to 31 March 1990.

Background: This AD resulted from a request by the National Transportation Safety Board (US) who while investigating a number of fatal MU 2B accidents, concluded that pilots were becoming confused in the operation of the interrupt/disconnect switches for the electric pitch trim and autopilot systems.