AD/HS 125/161 - Oxygen System

Administered by Department of Infrastructure, Transport, Regional Development, Communications, Sport and the Arts

Legislation au F2006B10443 Not in force Legislative Instrument

Legislation content

 



British Aerospace BAe 125 Series Aeroplanes

 

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 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.

 

AD/HS 125/161 Oxygen System 3/2000

Applicability: Models and series of aeroplanes as listed in the applicable Raytheon Aircraft Service Bulletin(s) (SB) specified in the following table:

 

Model of Aeroplane SB No SB Date

 

DH.125, HS.125, BH.125 series 1A, 1B, 3A, 3B, 400A, 400B, 401B, 403A,

403B, 600A, 600B, 700A, and 700B


SB 35-3169 September 1998

 

BAe.125 series 800A (C-29A) SB 35-3171 September 1998

 

BAe.125 series 800A, 800B, and Hawker 800

 

BAe.125 series 1000A, 1000B, and Hawker 1000


SB 35-3034 and

SB 35-3170

 

SB 35-3167 and

SB 35-3168


September 1998

 

September 1998

 

Requirement: 1. For Model DH.125, HS.125, BH.125 series 1A, 1B, 3A, 3B, 400A, 400B, 401B,

403A, 403B, 600A, 600B, 700A and 700B aeroplanes:

 

  1. Replace the cadmium plated cone caps in the oxygen system plumbing with improved cone caps, and perform a detailed visual inspection of the removed cone caps, tee-piece and sleeve for evidence of flaking or corrosion; in accordance with SB 35-3169 dated September 1998.

 

b.    If any flaking or corrosion is detected, clean the tee-piece and sleeve, and perform an oxygen system flow check in accordance with the SB.

 

c.    If any discrepancy is found during the flow check, repair the oxygen system in accordance with the SB, except as required by Requirement 5.

 

 

2.    For Model BAe.125 series 800A (C-29A) aeroplanes:

 

  1. Replace the cadmium plated cone caps in the oxygen system plumbing with improved cone caps, and perform a detailed visual inspection of the removed cone caps, tee-piece and sleeve for evidence of flaking or corrosion; in accordance with SB 35-3171, dated September 1998.

 

b.    If any flaking or corrosion is detected, clean the tee-piece and sleeve, and perform an oxygen system flow check in accordance with the SB.

 

c.    If any discrepancy is found during the flow check, repair the oxygen system in accordance with the SB, except as required by Requirement 5.

 

3.    For Model BAe.125 series 800A and 800B aeroplanes and Model Hawker 800 aeroplanes:

 

  1. Replace the cadmium plated cone caps in the oxygen system plumbing with improved cone caps, and perform a detailed visual inspection of the removed cone caps, tee-piece and sleeve for evidence of flaking or corrosion; in accordance with SB 35-3034 or SB 35-3170, both dated September 1998, as applicable.

 

b.    If any flaking or corrosion is detected, clean the tee-piece and sleeve, and perform an oxygen system flow check in accordance with the SB.

 

c.    If any discrepancy is found during the flow check, repair the oxygen system in accordance with the SB, except as required by Requirement 5.

 

4.    For Model BAe.125 series 1000A and 1000B aeroplanes and Model Hawker 1000 series aeroplanes:

 

  1. Replace the cadmium plated fittings in the oxygen system plumbing with improved fittings, and perform a detailed visual inspection of the removed fittings and the pipe connections for evidence of flaking or corrosion; in accordance with SB 35-3167 or SB 35-3168, both dated September 1998, as applicable.

 

b.    If any flaking or corrosion is detected, clean the pipe connections, and perform an oxygen system flow check in accordance with the SB.

 

c.    If any discrepancy is found during the flow check, repair the oxygen system in accordance with the SB, except as required by Requirement 5.

 

 

5.    If any discrepancy is found during a flow check required by Requirements 1, 2, 3 or 4 and the applicable SB specifies to contact the manufacturer for a repair disposition, repair the oxygen system in accordance with a method approved by the Manager, Technical Specialists Section, Certification Standards Branch, Civil Aviation Safety Authority, GPO Box 2005 Canberra ACT 2601, Facsimile (02) 6217 1914.

 

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."

 

Note 2: FAA AD 2000-03-35 Amdt 39-11553 refers.

 

Compliance: For Requirement 1.a. - Within 6 months after the effective date of this Directive.

 

For Requirement 1.b. - Before further flight. For Requirement 1.c. - Before further flight.

For Requirement 2.a. - Within 6 months after the effective date of this Directive. For Requirement 2.b. - Before further flight.

For Requirement 2.c. - Before further flight.

 

For Requirement 3.a. - Within 6 months after the effective date of this Directive. For Requirement 3.b. - Before further flight.

For Requirement 3.c. - Before further flight.

 

For Requirement 4.a. - Within 6 months after the effective date of this Directive. For Requirement 4.b. - Before further flight.

For Requirement 4.c. - Before further flight. For Requirement 5 - Before further flight.

This Airworthiness Directive becomes effective on 23 March 2000.

 

 

Background:  The Federal Aviation Administration has advised that Raytheon received reports indicating that a field survey revealed that a reaction process was occurring, which resulted in cadmium flaking. The flaking could cause blocking of valves resulting in impairing the function of the oxygen system, which could deprive the crew and passengers of necessary oxygen during an emergency that requires oxygen.

 

This Directive specifies actions designed to prevent flaking of cadmium from certain oxygen system plumbing fittings and cone caps from blocking the valves.

 


 

William Ronald Smith

Delegate of the Civil Aviation Safety Authority 10 February 2000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


The above AD is notified in the Commonwealth of Australia Gazette on 23 February 2000.

Overview

The Civil Aviation Safety Authority (CASA) issued the Airworthiness Directive (AD) AD/HS 125/161 in 2000 to address safety concerns related to the oxygen systems of British Aerospace BAe 125 Series Aeroplanes. This AD was enacted to mitigate the risk of cadmium flaking in the oxygen system plumbing fittings and cone caps, which could potentially block valves and impair the function of the oxygen system during an emergency, thereby endangering the crew and passengers. The directive mandates specific actions, including the replacement of cadmium plated cone caps and fittings with improved versions and detailed visual inspections for evidence of flaking or corrosion, with compliance timeframes set for both the replacement and the subsequent inspections to ensure that any detected discrepancies are rectified before further flights. The AD was published in the Commonwealth of Australia Gazette on 23 February 2000, following a recommendation by the Federal Aviation Administration based on reports from Raytheon indicating cadmium flaking in the affected aeroplanes' oxygen systems.

Scope and Application

The Airworthiness Directive (AD) issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998 applies specifically to certain models of British Aerospace BAe 125 Series aeroplanes, including the DH.125, HS.125, BH.125, BAe.125 series 800A (C-29A), BAe.125 series 800A, 800B, Hawker 800, BAe.125 series 1000A, 1000B, and Hawker 1000. The AD mandates specific actions to be taken to correct an unsafe condition identified in the oxygen system plumbing. The directive is applicable nationwide within the Commonwealth of Australia and is enforced by the Civil Aviation Safety Authority (CASA). The requirements include replacing cadmium plated cone caps with improved versions, conducting detailed visual inspections, and performing flow checks, with repairs to be executed as specified in the referenced service bulletins. The directive does not specify any exclusions or exemptions, and compliance must be achieved within stipulated timeframes before further flight. The AD became effective on 23 March 2000 and was issued following reports of cadmium flaking in the oxygen system, which could potentially impair oxygen supply during emergencies.

Key Provisions

The Airworthiness Directive AD/HS 125/161 issued by the Civil Aviation Safety Authority (CASA) under subregulation 39.1(1) of CAR 1998 mandates specific actions for the safety of certain British Aerospace BAe 125 Series Aeroplanes. These actions are aimed at correcting the unsafe condition related to the oxygen system. The directive applies to specific models and series of aeroplanes as detailed in the applicable Raytheon Aircraft Service Bulletins (SB) dated September 1998. For these aeroplanes, the directive requires the replacement of cadmium plated cone caps in the oxygen system plumbing with improved cone caps, and a detailed visual inspection of the removed cone caps, tee-piece, and sleeve for evidence of flaking or corrosion, as outlined in the respective service bulletins. If flaking or corrosion is detected, further actions such as cleaning the tee-piece and sleeve, performing an oxygen system flow check, and repairing the oxygen system as specified in the service bulletins are required before further flight. The obligations imposed by this Airworthiness Directive on the parties it governs include ensuring compliance with the specified actions within a defined timeframe and before further flight, as outlined in the compliance section of the directive. For certain actions, compliance must be achieved within six months of the directive's effective date, while others must be addressed before further flight. These requirements mandate a thorough inspection and, if necessary, corrective measures to ensure the safety of the aeroplanes' oxygen systems. Failure to comply with the Airworthiness Directive AD/HS 125/161 can result in serious consequences. The directive does not explicitly state penalties or legal consequences for non-compliance, but non-compliance could potentially lead to the aeroplane being deemed airworthy, which could result in safety risks and legal repercussions. Ensuring adherence to the directive is critical to maintaining the safety standards required by the Civil Aviation Safety Authority.

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Sourced from the Federal Register of Legislation at 26 August 2026. For the latest information on Australian Government law please go to https://www.legislation.gov.au.