AD/CESSNA 336/14 - Upper Shoulder Harness Adjuster Spring

Overview

The Airworthiness Directive issued under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998 by the Civil Aviation Safety Authority (CASA) addresses a safety concern identified with the Cessna 336 Series aeroplanes. Specifically, the Airworthiness Directive AD/CESSNA 336/14 pertains to the upper shoulder harness adjuster spring, which was issued on 13/2004 and became effective on 23 December 2004. The directive was introduced to mitigate the risk of slippage in the pilot/co-pilot shoulder harness, which could compromise the proper adjustment and tension of the belt, thereby posing a safety hazard during flight. The requirement for compliance involves inspecting the upper shoulder harness adjuster for the presence of a retainer spring and, if found, removing it by cutting each side and stamping out the identification number as per the Service Bulletin MEB86-22 Revision 1. If the spring is not found, an entry must be made in the aircraft logbook indicating compliance with the directive. This directive is intended to ensure that only Cessna Accessory Kits that have been inspected and modified in accordance with the requirement document are incorporated.

Scope and Application

The Airworthiness Directive (AD) issued under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998 by the Civil Aviation Safety Authority (CASA) applies specifically to Model 336 aircraft with serial numbers detailed in the Cessna Multi-Engine Service Bulletin (SB) MEB86-22 Revision 1, dated 28 July 2003. This AD mandates that certain actions be taken to address an identified unsafe condition relating to the upper shoulder harness adjuster. The directive requires an inspection of the upper shoulder harness adjuster (part number 443030-401) for the presence of a retainer spring and stipulates that if such a spring is found, it must be removed before further flight. Compliance with these requirements must occur within 25 hours of the aircraft’s time in service or at the next annual inspection after 23 December 2004, whichever comes first. The AD is effective as of 23 December 2004 and is applicable across the Commonwealth of Australia, aligning with the regulatory oversight exercised by CASA.

Key Provisions

This Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) mandates specific actions concerning the upper shoulder harness adjusters of certain Cessna 336 series aircraft (sections 1-3). The AD applies to Model 336 aircraft with specific serial numbers as listed in the Cessna Multi-Engine Service Bulletin (SB) MEB86-22 Revision 1, dated 28 July 2003 (section 4). The requirement is to inspect the upper shoulder harness adjuster (part number 443030-401) for the presence of a retainer spring, in accordance with SB MEB86-22 Revision 1 (section 5). If a retainer spring is found, it must be removed by cutting each side and the -401 identification number must be stamped out, also in accordance with the same bulletin (section 5). If no retainer spring is found, an entry must be made in the aircraft log book to show compliance with this directive (section 5). Additionally, only Cessna Accessory Kits that have been identified, inspected, and modified in accordance with the requirement document may be used (section 5). The AD imposes several obligations on the parties it governs. Firstly, it requires the inspection of the specified part of the aircraft (section 5). If a retainer spring is found during the inspection, it must be removed and the identification number stamped out (section 5). If no retainer spring is found, a compliance entry must be made in the aircraft log book (section 5). Secondly, only specific accessory kits may be used in the aircraft (section 5). These requirements must be met within 25 hours of the aircraft's time in service or at the next annual inspection after 23 December 2004, whichever occurs first (section 6). Compliance with SB MEB86-22 original issue, dated 21 November 1986, constitutes terminating action for the requirements of this directive if the specific shoulder harness adjuster part was used (section 6). Failure to comply with the AD can result in serious consequences. The directive is intended to prevent the slippage of the pilot/co-pilot shoulder harness, which could result in the failure of the shoulder harness to maintain proper belt length adjustment and tension, potentially leading to unsafe conditions during flight (section 8). While the AD does not explicitly state penalties for non-compliance, the potential for unsafe conditions implies that failure to comply could result in severe safety risks, and potentially civil or criminal consequences under other applicable aviation legislation.