AD/B717/17 - Brake Fuses

The Directive rests on a small set of concrete components, deadlines and prescriptive service information. Applicability narrows the rule to a defined production block of Boeing 717-200 aeroplanes, fuselage numbers 5002-5134 inclusive (Applicability). The core concept is part replacement: remove eight instances of a specified existing part, P/N 7918282-5503, and replace them with parts identified as P/N 7918282-5505 either new or modified (Requirement; Table 1). The AD explicitly forbids re-installation of the old part number after issuance: "Do not install a brake fuse, P/N 7918282-5503, on any aeroplane" (Requirement, para 2).

The Directive ties the mechanical action to specific manufacturer service instructions. Compliance must be accomplished "in accordance with Boeing Alert Service Bulletin 717-32A0031, dated 10 September 2004" (Requirement, para 1). For the modification/reidentification pathway, Boeing’s SB refers to Parker Hannifin Corporation Stratoflex Products Division Service Bulletin 836SD-8-6-20 Revision 1, dated 23 June 2004, as additional service information (Note 1). Thus the AD makes specific technical procedures normative by incorporation of those service bulletins.

Timing is measured in operational usage units, not calendar time: compliance windows are expressed in flight cycles (Table 2). The Directive differentiates aircraft based on accumulated total flight cycles as of the effective date: two tiers (<5,000 cycles and ≥5,000 cycles) with corresponding compliance windows (3,600 cycles and 1,500 cycles respectively). The Background sets out the risk model: simultaneous failure of one fuse on each hydraulic system could result in loss of both a hydraulic and a brake system and reduced controllability (Background). The AD references an FAA airworthiness directive as related material: "FAA AD 2005-11-03 Amdt 39-14105 refers" (Note 2).

Mechanically, therefore, the AD is prescriptive: (1) identify applicability by fuselage number; (2) determine total flight cycles as of the effective date; (3) select replacement Option 1 or Option 2; (4) perform replacement per Boeing SB (and Parker SB for Option 2); (5) do not install the old part number thereafter. These are the enumerated, enforceable actions contained in the source text.

The Directive directly affects operators and maintainers of Boeing Model 717-200 aeroplanes carrying fuselage numbers 5002 through 5134 inclusive (Applicability). That cohort is explicitly defined; aircraft outside that fuselage-number range are not within the scope of this specific instrument. The parties who must act are those responsible under the operator's maintenance and continuing airworthiness responsibilities, because the Directive mandates physical replacement of the specified parts and prescribes procedural references for how to do it (Requirement; Table 1).

Secondary affected parties include parts suppliers and maintenance organisations. The replacement requires parts P/N 7918282-5505 (Table 1). Where Option 2 is chosen, organisations capable of performing the modification and reidentification in accordance with Parker Hannifin service information will be implicated (Note 1). The Directive does not itself name or certify particular maintenance shops; it references manufacturer service bulletins as the normative technical route.

Regulatory counterparts and international operators are also signalled: the AD references a related FAA airworthiness directive (FAA AD 2005-11-03 Amdt 39-14105) as related material (Note 2). That indicates the issue has been addressed in other jurisdictions, which may affect international operators operating under multiple authorities, though the Directive itself applies to the Australian authority’s jurisdiction and to the specified serial-numbered aeroplanes.

Who pays: the source requires replacement of hardware and likely labour to perform the change. The Directive makes the replacement mandatory within specified flight-cycle windows; the direct financial and scheduling burden will fall on the aircraft operator or the party contractually responsible for aircraft maintenance and parts procurement. The document does not allocate costs, set funding, or provide financial assistance; those are matters outside the text. Who decides: an operator or approved maintenance organisation decides whether to use Option 1 (install new P/N 7918282-5505) or Option 2 (modify and reidentify to P/N 7918282-5505), but the work must be done "in accordance with Boeing Alert Service Bulletin 717-32A0031" (Requirement). Behaviour changes: operators must schedule the replacements within flight-cycle windows, stop installing the older P/N 7918282-5503 from the effective date, and follow the prescribed service instructions when undertaking the replacement.

Key duties are enumerated by the Directive’s Requirement and Compliance sections and the related tables. Duty to inspect applicability: operators must determine whether an aeroplane is within the fuselage-number applicability range, i.e. model 717-200 fuselage numbers 5002-5134 (Applicability). Duty to determine accumulated flight cycles: compliance times are keyed to the total flight cycles as of the effective date, so operators must establish the aeroplane’s total flight cycles as of 4 August 2005 to determine which compliance window applies (Compliance; Table 2).

Duty to replace: operators must "Replace the eight brake fuses of the hydraulic quantity limiter by doing either Option 1 or Option 2 in Table 1 of this Directive in accordance with Boeing Alert Service Bulletin 717-32A0031, dated 10 September 2004" (Requirement, para 1). This places a duty of performance , one of two authorised means to remove the risky P/N 7918282-5503 and put in P/N 7918282-5505.

Duty not to install: the Directive imposes a prohibition: "Do not install a brake fuse, P/N 7918282-5503, on any aeroplane" (Requirement, para 2). That prohibition, read alongside the "After the effective date of this Directive" fragment under Compliance, indicates that operators must not fit the old part number following the AD’s effective date.

Duty to follow service instructions: the replacement must be done "in accordance with Boeing Alert Service Bulletin 717-32A0031, dated 10 September 2004" (Requirement, para 1). For modified reidentification (Option 2), Boeing’s SB refers to Parker Hannifin Service Bulletin 836SD-8-6-20 Revision 1 (Note 1), which therefore forms part of the technical pathway to compliance for Option 2.

Express rights are not stated in the source. The Directive does not articulate appeal, exemption or deferment mechanisms in the text provided here. The only procedural element in the source that might be read as discretionary is the operator’s choice between two authorised options (install new P/N 7918282-5505 or use modified/reidentified P/N 7918282-5505). That choice is constrained by the requirement to accomplish the work "in accordance with" the identified Boeing Alert Service Bulletin (Requirement). The source also does not state an explicit right to continue operating until the compliance window expires, but by setting compliance windows in flight cycles it implicitly allows continued operation within those windows; the Directive prescribes when the replacements must occur and therefore sets operational limits by timing rather than immediate grounding.

The document does not state administrative processes (such as obtaining an approval for alternative methods of compliance) within its text. It also does not set out record-keeping obligations or certification steps once the change is made; those matters are likely handled by the usual maintenance regulatory framework but are not contained in the AD as supplied. Users must therefore rely on the AD’s explicit duties and on the referenced service bulletins for the technical method of compliance.

The source text does not set out monetary penalties, criminal penalties, or specific enforcement procedures. The document is an Airworthiness Directive that becomes effective on 4 August 2005 and is issued by a Civil Aviation Safety Authority delegate, James Coyne (effective date and signature). The Directive prescribes mandatory technical and timing requirements for specified aeroplanes (Requirement; Table 2). What the text does provide is the effective date and the prescriptive replacement and prohibition obligations: replace the eight brake fuses per the options in Table 1 and do not install P/N 7918282-5503 (Requirement; Table 1; para 2).

Because the AD text itself is silent on enforcement mechanics and sanctions, the document as provided does not describe the mechanisms by which compliance will be monitored, the remedial steps for non-compliance, or any penalties that may be imposed for failing to comply. The AD does reference FAA AD 2005-11-03 Amdt 39-14105 (Note 2), but that is a cross-reference to another authority’s instrument and does not in itself provide enforcement details within this document.

For operational purposes the practical enforcement question for operators is whether an airworthiness regulator will tie valid operation and airworthiness certification to compliance with the AD. The source does not include that linkage in express terms, nor does it include wording about exemptions, deferred compliance approvals, or alternative methods of compliance. The operator must therefore treat the AD’s stated requirements, deadlines and prohibitions as binding obligations set out in the AD and seek authoritative clarification from the issuing authority if a formal statement on enforcement or penalties is required, because such material is not present in the text provided.

The Directive explicitly cross-references manufacturer service bulletins and a related FAA airworthiness directive. The replacement work must be "in accordance with Boeing Alert Service Bulletin 717-32A0031, dated 10 September 2004" (Requirement). Boeing’s alert service bulletin itself refers to Parker Hannifin Service Bulletin 836SD-8-6-20 Revision 1, dated 23 June 2004, as additional service information for modifying and reidentifying the brake fuses (Note 1). Those service bulletins serve as the technical standards incorporated by reference for the mechanical action required by the AD.

The Directive also notes: "FAA AD 2005-11-03 Amdt 39-14105 refers" (Note 2). That indicates a related instrument issued by the United States Federal Aviation Administration addresses the same technical issue, creating a cross-jurisdictional alignment of safety action. The AD as supplied does not contain text explaining how operators subject to multiple regulatory regimes should coordinate compliance, nor does it spell out whether compliance with the FAA AD is sufficient or whether the CASA AD imposes additional requirements beyond the FAA’s measure. The textual evidence is limited to the cross-reference; any legal interface between this AD and other domestic statutes, regulations, or administrative processes is not described in the document as provided.

The AD also incorporates procedural material , the Boeing and Parker service bulletins , as authoritative technical content to be followed. Incorporation of manufacturer service instructions into a regulatory instrument changes the status of those instructions from guidance to prescriptive requirements for the affected aeroplanes. The AD’s text thereby binds operators to the specific technical measures set out in those service bulletins insofar as the AD requires compliance "in accordance with" them.

The source does not discuss interactions with other statutory obligations, such as continuing airworthiness record-keeping, or with contractual arrangements between operators and maintenance providers. Those interactions are not asserted or described in the text supplied; any operator needing a full legal compliance picture should consult the issuing regulator or the broader regulatory framework in which airworthiness directives operate, because the AD itself limits its cross-references to the Boeing/Parker service information and the FAA AD 2005-11-03.

The Directive text supplied contains no amendment history entries beyond its initial issuance and effective date. The document displays an issuance date of 24 June 2005, signed by James Coyne, Delegate of the Civil Aviation Safety Authority, and states that "This Airworthiness Directive becomes effective on 4 August 2005" (signature and effective date). There are no further dated amendments, revocations, supersessions or corrigenda present in the material provided.

The only dated service materials referenced are Boeing Alert Service Bulletin 717-32A0031 dated 10 September 2004 and Parker Hannifin Service Bulletin 836SD-8-6-20 Revision 1 dated 23 June 2004 (Requirement; Note 1). The AD also refers to FAA AD 2005-11-03 Amendment 39-14105 (Note 2). But the Directive itself, as given, reflects a single issuance event and a single effective date, with no later amendment chronology recorded in the text.

The absence of an amendment history in the supplied document means the version under review is the original instrument as published with that effective date. Users should be aware that subsequent amendments or superseding ADs could exist outside the provided text; the document itself does not purport to be updated beyond the initial issue. If a reader needs the current regulatory status, they must consult the issuing authority’s records or an updated official repository because the supplied document contains only the initial AD and no amendment trail.

The source document contains no litigation history. It records the AD content, applicability, requirements, service bulletin references, compliance windows and effective date, together with a short Background explaining the safety rationale (Background). It does not mention any court proceedings, appeals, disputes, petitions for review, or case law arising from the Directive.

Because no litigation material appears in the text provided, there is no basis in the source to report on judicial interpretations, challenges to the AD’s scope, or contested enforcement actions. If a practitioner requires information on whether this AD has been the subject of litigation, they will need to consult court records, administrative tribunal files, or the issuing regulator’s communications outside the supplied AD. The AD itself is silent on remedies, appeals, or legal challenges.

The text contains a number of details that can cause practical misapplication if overlooked.

1. Applicability is narrow and serial-number based. The AD applies only to Boeing Model 717-200 aeroplanes with fuselage numbers 5002 through 5134 inclusive (Applicability). Operators must confirm the fuselage number before applying the AD. Treating the AD as a model-wide requirement without confirming serial-number applicability would be an error.

2. Two-part-number nuance. The AD requires removal of P/N 7918282-5503 and replacement with parts having P/N 7918282-5505 (Table 1). Both authorised Options 1 and 2 yield P/N 7918282-5505, but Option 2 allows use of modified and reidentified parts rather than fresh new parts. Misreading the Options and installing an incorrect part number would contravene the AD.

3. Choice between new and modified parts must follow Boeing SB. Option 2’s permissibility depends on performing the modification and reidentification consistent with the service information. The AD incorporates Boeing Alert Service Bulletin 717-32A0031 dated 10 September 2004 as the governing technical instruction (Requirement, para 1). Boeing’s SB, in turn, points to Parker Hannifin SB 836SD-8-6-20 Revision 1 as additional service information for the modification pathway (Note 1). Using a different modification method without regulatory approval would not satisfy the AD as written.

4. Timing is in flight cycles and depends on accumulated cycles as of the effective date. Compliance windows are set as flight-cycle counts after the effective date and are tiered according to whether the aeroplane had fewer than 5,000 cycles or 5,000 or more as of the effective date (Table 2). Operators must therefore establish and document the flight-cycle count on 4 August 2005 to determine the correct compliance window. Miscounting cycles or using hours or calendar time instead of flight cycles would be a misapplication.

5. Prohibition language and an orphaned sentence. The AD contains the clear prohibition "Do not install a brake fuse, P/N 7918282-5503, on any aeroplane" (Requirement, para 2). Under the Compliance header there is a short, standing-alone sentence "2. After the effective date of this Directive." The sentence appears orphaned and could create ambiguity about whether it is intended to qualify the prohibition or other requirements. The precise legal force of that fragment is not elaborated in the supplied text; practitioners should treat the prohibition as absolute and seek confirmation from the regulator if the orphaned clause’s intended scope matters for compliance strategy.

6. Cross-references to external documents. The AD makes Boeing’s SB normative by reference; if an operator relies on Option 2 they must consult both Boeing and Parker SBs. Failing to obtain and follow those service bulletins precisely risks non-compliance.

7. No explicit administrative exceptions or alternative method of compliance in the text. The AD does not set out an approval process for alternative methods of compliance within the supplied material. If an operator wishes to pursue a different technical solution, the AD provides no procedural pathway in its text; that is a separate administrative process outside the AD as given.

8. Effective date versus issuance date. The AD was signed on 24 June 2005 and becomes effective on 4 August 2005 (signature and effective date). Operators must be careful to use the effective date for counting compliance windows.

Follow these concrete steps, grounded in the AD text:

1. Confirm applicability. Verify that the aeroplane is a Boeing Model 717-200 and that its fuselage number is within 5002-5134 inclusive (Applicability). If the aeroplane is outside that serial-number range, the AD does not apply as written.

2. Establish flight-cycle baseline. Determine the aeroplane’s total flight cycles as of the effective date, 4 August 2005, because Table 2 sets different compliance windows depending on whether that baseline is less than 5,000 cycles or 5,000 or more (Compliance; Table 2).

3. Select authorised compliance option. Choose either Option 1 (install new fuses P/N 7918282-5505) or Option 2 (install modified and reidentified fuses P/N 7918282-5505) as set out in Table 1 of the Directive. Both options result in P/N 7918282-5505 being installed, but Option 2 requires performing the modification and reidentification procedure that Boeing’s SB references (Table 1; Requirement).

4. Use the mandated service instructions. Perform the replacement "in accordance with Boeing Alert Service Bulletin 717-32A0031, dated 10 September 2004" (Requirement, para 1). If using Option 2, consult Parker Hannifin Stratoflex Service Bulletin 836SD-8-6-20 Revision 1 dated 23 June 2004, which Boeing’s SB refers to as additional service information for the modification/reidentification procedure (Note 1).

5. Schedule within the correct compliance window. If the aeroplane had fewer than 5,000 total flight cycles as of 4 August 2005, accomplish the replacement within 3,600 flight cycles after that effective date. If it had 5,000 or more cycles as of the effective date, accomplish the replacement within 1,500 flight cycles after the effective date (Compliance; Table 2). Because the compliance windows are measured in flight cycles, plan the maintenance and parts logistics on that metric.

6. Do not re-install the old part number. After compliance, and in any case per the prohibition in the AD, do not install or re-install brake fuse P/N 7918282-5503 on any aeroplane (Requirement, para 2).

7. Obtain the service bulletins and follow them precisely. The AD makes Boeing Alert SB 717-32A0031 the normative technical document; obtain the exact dated SB and follow the instructions therein. For Option 2 modifications, obtain the Parker Hannifin SB referenced in Boeing’s SB and follow it for modification and reidentification (Requirement; Note 1).

8. Coordinate maintenance planning. The Directive imposes a discrete hardware change on eight fuses per aeroplane. Ensure maintenance slots, parts acquisition for P/N 7918282-5505 and appropriate technical personnel or maintenance organisation capacity are arranged within the flight-cycle window applicable to the aircraft.

9. If anything is unclear, seek regulator guidance. The AD’s text contains a fragmentary sentence "2. After the effective date of this Directive." under Compliance that could be read as an orphaned clause. The AD does not set out administrative exception processes or enforcement mechanisms in the supplied text; if operators need clarity on the interpretation of that fragment, the interaction with other requirements (for example, record-keeping or certification), or want to pursue an alternative method of compliance, they should seek formal guidance from the issuing authority because those procedures are not contained in the AD as provided.

10. Note related instruments. The AD references FAA AD 2005-11-03 Amdt 39-14105 (Note 2). If the operator is subject to multiple airworthiness authorities, confirm that completing the required replacement in accordance with this AD and its incorporated service bulletins will satisfy any parallel requirements under other authorities, or take any additional steps required by those authorities.

Following these steps will render the eight brake fuses compliant with AD/B717/17 as set out in the source document: replacement with P/N 7918282-5505 achieved by one of the two authorised options, accomplished within the flight-cycle window for the aircraft’s baseline cycles as of 4 August 2005, and with the prohibition on installing the old P/N 7918282-5503 observed.