AD/B737/100 - Aileron Control Cable Pulley Bracket

Overview

The Civil Aviation Regulations 1998, as amended, are fundamental to ensuring the safety and airworthiness of aircraft operating within Australian airspace. This legislation, enacted by the Commonwealth of Australia, addresses specific safety concerns and sets out detailed requirements to mitigate risks associated with aircraft operation. Part 39 of these regulations, particularly the 105th Civil Aviation Safety Authority Schedule of Airworthiness Directives, focuses on specific directives for certain aircraft models, such as the Boeing 737 Series. The policy objective behind these directives is to ensure the structural integrity and operational safety of aircraft by mandating regular inspections and repairs as necessary. The regulatory framework established by these directives aims to prevent potential failures and enhance overall aviation safety, thereby protecting passengers, crew, and the general public. The Airworthiness Directive AD/B737/100 concerning the Boeing 737 Series Aeroplanes, specifically addressing the aileron control cable pulley bracket, exemplifies the proactive measures implemented by the Civil Aviation Safety Authority. This directive was introduced in response to identified safety issues related to the fatigue cracking, base trim, or upper flange over-trim of certain pulley brackets. By requiring visual inspections and appropriate corrective actions, such as replacement of defective components, the directive ensures that any potential risks are mitigated effectively. This proactive approach aligns with the overarching goal of maintaining high safety standards in civil aviation, reflecting the commitment to ensuring the reliability and safety of aircraft operations within Australia.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to the Boeing 737 Series Aeroplanes, with the focus of this directive being the aileron control cable pulley brackets. This applies to aircraft within the 737-300 series, as referenced in Boeing Service Bulletin 737-27-1154. The directive mandates a visual inspection to detect any instances of fatigue cracking, base trim, or upper flange over-trim of the specified pulley brackets, which are part numbers 65C25555-3, 65C5555-501, or 69-73479-1. If any of these issues are found, the directive requires the replacement of the affected pulley brackets with new ones and the substitution of the existing button-head rivets with flush-head rivets, in accordance with the same Boeing Service Bulletin. This directive is effective from 24 April 1997 and compliance is necessary before 14 September 1998 unless the actions have already been completed. This directive does not specify any exclusions, exemptions, or thresholds, and it is applicable across the Commonwealth of Australia under the purview of the Civil Aviation Safety Authority.

Key Provisions

The Civil Aviation Regulations 1998, under PART 39 - 105, establish specific airworthiness directives for the Boeing 737 Series Aeroplanes, with the directive AD/B737/100 focusing on the aileron control cable pulley bracket (subsection 5/97). This directive applies specifically to the Boeing 737-300 series aircraft as listed in Boeing Service Bulletin 737-27-1154. The directive mandates a visual inspection of the pulley brackets (section 5/97(a)) to detect any fatigue cracking, base trim, or upper flange over-trim. The affected pulley brackets are identified by part numbers 65C25555-3, 65C5555-501, or 69-73479-1. If any such defects are detected, the directive requires the replacement of the faulty pulley brackets with new ones and the replacement of the existing button-head rivets with flush-head rivets, in accordance with the specified Boeing Service Bulletin (section 5/97(b)). The obligations imposed by this directive are clear and specific. Operators of Boeing 737-300 series aircraft must ensure that the visual inspections and necessary replacements are carried out as directed, following the procedures outlined in Boeing Service Bulletin 737-27-1154. Compliance with this directive is mandatory, and it must be completed before 14 September 1998 if not already done (subsection 5/97). This directive became effective on 24 April 1997, providing a timeframe within which compliance must be achieved. The directive references FAA AD 97-03-14 Amdt 39-9919, indicating a collaborative effort between Australian and US aviation authorities in addressing the identified safety issues. Failure to comply with the requirements of this airworthiness directive can lead to serious safety concerns, as it is a critical component of the aircraft's flight control system. The directive aims to prevent potential malfunctions that could compromise the aircraft's operational safety. In terms of consequences, while the specific penalties for non-compliance are not detailed in this excerpt, breaches of airworthiness directives under the Civil Aviation Regulations 1998 can result in severe penalties. These may include civil penalties, such as fines, and criminal charges for individuals responsible for non-compliance. The severity of these penalties can vary, but they are designed to enforce strict adherence to safety standards to protect passengers and crew. The directive underscores the importance of rigorous maintenance and inspection protocols to ensure the continued airworthiness of the aircraft.