AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 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.
Boeing 747 Series Aeroplanes
AD/B747/265 Passenger Service Units Electrical Wire Bundle Chafing
2/2002
Applicability: Model 747 series aeroplanes, as listed in Boeing Alert Service Bulletin (ASB) 747- 35A2035, Revision 1, dated 22 July 1999.
Requirement: 1. Perform a detailed visual inspection for chafing between oxygen hoses and electrical wire bundles at the passenger service units (PSU) in the main deck passenger compartment, upper deck sculpted ceiling, personnel accommodation (crew rest) area, lower lobe forward galley, and aft galley. Inspections are to be performed in accordance with ASB 747-35A2035, Revision 1, as revised by Boeing Service Bulletin Information Notice 747-35A2035 IN 01, dated 23 September 1999.
Note 1: For the purposes of this Directive, a detailed visual inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”
2. If, as a result of the Requirement 1 inspection, any discrepancies are detected, complete any necessary repairs as specified in Requirement 2.a. and/or 2.b., as applicable. Additionally, reroute the oxygen hose or install an elbow at the oxygen mask inlet connector to reorient the oxygen hose away from the electrical wiring to ensure a minimum of 2 inches clearance between the oxygen hose and electrical wire bundle, in accordance with ASB 747-35A2035, Revision 1.
- If any chafing of an oxygen hose is found - Replace the chafed oxygen hose with a new oxygen hose, and install protective sleeving over the new oxygen hose, in accordance with ASB 747-35A2035, Revision 1.
b. If any chafing of a wire bundle is found - Repair the wire bundle in accordance with ASB 747-35A2035, Revision 1.
Inspections and follow-on actions accomplished prior to the effective date of this Directive in accordance with Boeing SB 747-35-2035, dated 7 January 1983, are acceptable for compliance with corresponding actions of this Directive.
Note 2: FAA AD 2001-24-29 Amdt 39-12546 refers.
Boeing 747 Series Aeroplanes
AD/B747/265 (continued)
Compliance: For Requirement 1 - Before 16 July 2003.
For Requirement 2 - Before further flight following the Requirement 1 inspection. This Airworthiness Directive becomes effective on 21 February 2002.
Background: This Directive requires a one-time inspection for chafing between the hose for the passenger oxygen system (hereinafter called the "oxygen hose'') and adjacent electrical wire bundles at certain passenger service units and, if necessary, corrective actions. The Directive also requires rerouting or reorienting the oxygen hose to ensure sufficient clearance between the hose and electrical wire bundles.
These actions are necessary to prevent chafing between the oxygen hose and adjacent electrical wire bundles, which could result in arcing of a chafed electrical wire bundle and consequent burn-through of the oxygen hose. If this occurs when the oxygen system is pressurized, such arcing could represent a potential ignition source in an oxygen-enriched environment.
Eugene Paul Holzapfel
Delegate of the Civil Aviation Safety Authority 14 January 2002
The above AD is notified in the Commonwealth of Australia Gazette on 30 January 2002.
Overview
The Boeing 747 Series Aeroplanes Airworthiness Directive 2002 (AD/B747/265) was enacted to address the potential safety risk posed by chafing between oxygen hoses and electrical wire bundles at specific locations within the aircraft. This AD was issued by the Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998. The problem this directive seeks to resolve is the risk of arcing due to chafing, which could potentially lead to burn-through of the oxygen hose, posing a significant hazard, particularly in an oxygen-enriched environment. The policy objective is to ensure the airworthiness of the aircraft by implementing necessary inspections and corrective actions to prevent such chafing incidents, thereby maintaining safety standards in accordance with CASA’s regulatory framework.
Scope and Application
The Airworthiness Directive (AD) issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998 pertains specifically to the Boeing 747 series aeroplanes, as detailed in Boeing Alert Service Bulletin (ASB) 747-35A2035, Revision 1, dated 22 July 1999. This AD mandates that a detailed visual inspection for chafing between oxygen hoses and electrical wire bundles be conducted in several specific areas of the aircraft, including the main deck passenger compartment, upper deck sculpted ceiling, personnel accommodation area, and the galleys. The AD requires these inspections to be carried out before 16 July 2002, with any detected discrepancies necessitating immediate corrective actions to be completed before further flight. This directive applies nationally across the Commonwealth of Australia and is applicable to all relevant aircraft within the specified series. It aims to prevent potential safety hazards, such as arcing due to chafed wires, which could lead to burn-through of the oxygen hose and pose a risk in an oxygen-enriched environment. The AD is effective from 21 February 2002, and compliance is enforced by the Civil Aviation Safety Authority.
Key Provisions
The Airworthiness Directive (AD) issued under subregulation 39.1 (1) of CAR 1998 is applicable to Boeing 747 series aeroplanes listed in Boeing Alert Service Bulletin (ASB) 747-35A2035, Revision 1, dated 22 July 1999 (Section 1). The AD mandates a detailed visual inspection for chafing between oxygen hoses and electrical wire bundles at various passenger service units (PSU) in specific areas of the aircraft, such as the main deck passenger compartment, upper deck sculpted ceiling, personnel accommodation (crew rest) area, lower lobe forward galley, and aft galley (Section 1). This inspection must be conducted in accordance with ASB 747-35A2035, Revision 1, as revised by Boeing Service Bulletin Information Notice 747-35A2035 IN 01, dated 23 September 1999 (Section 1). If discrepancies are detected during this inspection, corrective actions must be taken immediately, including rerouting or reorienting the oxygen hose to ensure a minimum of 2 inches clearance between the oxygen hose and electrical wire bundle, and replacing the chafed oxygen hose with a new one, as well as installing protective sleeving over the new hose (Section 1).
The AD imposes several obligations on the parties governed by it. Firstly, operators of Boeing 747 series aeroplanes must perform a detailed visual inspection for chafing between oxygen hoses and electrical wire bundles at specified PSU locations (Section 1). This inspection must adhere to the guidelines outlined in ASB 747-35A2035, Revision 1, and Boeing Service Bulletin Information Notice 747-35A2035 IN 01, dated 23 September 1999 (Section 1). If chafing is detected during this inspection, the AD requires the completion of necessary repairs, including replacing chafed oxygen hoses and protective sleeving, as well as repairing wire bundles (Section 1). These inspections and corrective actions must be completed before the specified compliance dates (Section 1). Additionally, inspections and follow-on actions performed before the effective date of this AD in accordance with Boeing SB 747-35-2035, dated 7 January 1983, are acceptable for compliance with the corresponding actions of this Directive (Section 1).
Failure to comply with the AD may result in safety risks, such as chafing between the oxygen hose and adjacent electrical wire bundles, which could lead to arcing and potential burn-through of the oxygen hose in an oxygen-enriched environment. This could pose a significant hazard during flight, as it could create a potential ignition source. Although the AD does not explicitly mention penalties for non-compliance, non-compliance with ADs can lead to severe consequences, including potential grounding of the aircraft and civil or criminal liability for any accidents or incidents resulting from non-compliance. The maximum penalties for non-compliance with ADs can vary, but they may include substantial fines and imprisonment, depending on the severity of the breach and its impact on aviation safety.