For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Beechcraft 56TC (Turbo Baron) Series Aeroplanes
Beechcraft Forward Elevator
Cable - Replacement
All Beechcraft 56 series (Turbo Baron) aeroplanes fitted with the early ‘single-pole’ design control system.
Note 1: ‘Single pole’ design refers to the arrangement whereby the pilot’s control yokes are supported by a single shaft moving in and out of the instrument panel for elevator (pitch) control.
1. Inspect the forward elevator control cable assembly for wear, broken wires and corrosion.
2. Remove from service any forward elevator control cable assembly found to be defective as a result of inspection conducted in accordance with Requirement 1 of this AD.
3. Remove from service any forward elevator control cable assembly which has been in service for more than 15 years.
4. Perform an inspection of the elevator flight control system cable assemblies along their entire length for wear, broken wires and corrosion.
5. Remove from service any aircraft elevator flight control cable assemblies found to be defective as a result of inspection in accordance with Requirement 4 of this AD.
6. Do not install on any aircraft a cable assembly or parts thereof that have been removed in accordance with Requirements 2, 3 or 5 of this AD.
Note 2: Inspections carried out in accordance with FAA AC 43-13-1B, chapter 7, Section 8, paragraph 7-149(d) or Beechcraft maintenance data are an acceptable means of compliance for the inspections called up by Requirements 1 and 4 of this AD.
For those aircraft that have not had the forward elevator cable assembly replaced or inspected within the last maintenance release period - Before further flight after the effective date of the AD.
For those aircraft located where the inspection cannot be carried out - one positioning flight (pilot only) is allowed to a place where the inspection can be carried out.
For those aircraft that have had the forward elevator cable assembly replaced or inspected within the last maintenance release period - At the next scheduled maintenance inspection after the effective date of this AD. Compliance with Requirement 4 of this AD satisfies Requirement 1 of this AD for those aircraft.
Requirement 2. Before further flight.
Requirement 3. Within 60 days from the effective date of this AD.
Requirement 4. At the next scheduled maintenance inspection after the effective date of this AD, and thereafter, at intervals not exceeding 110 flight hours or 12 months time in service, whichever occurs first.
Requirement 5. Before further flight.
Requirement 6. After the effective date of this AD.
This Airworthiness Directive becomes effective on 16 January 2012.
CASA has received a report describing a forward elevator cable failure (separation) immediately prior to take-off. The elevator remained firmly in the full ‘down’ position due to system spring tension. See figure 1 for photograph of failed cable.
A second aircraft was inspected at the owner’s request immediately following the discovery of the failed cable. The forward elevator cable in this aircraft was found to be extensively frayed in the same location as the failed cable.
This Directive requires immediate inspection of the forward elevator cable and replacement for elevator cables over 15 years old. The AD requires continuing inspections of the entire elevator control system to preclude the unanticipated failure of the elevator flight control system which may result in loss of control of the aircraft.
Delegate of the Civil Aviation Safety Authority
16 January 2012