AD/HS 125/175 - Emergency Radio Wiring

The core concepts of the Directive are targeted applicability, specified technical instructions, graded compliance timing, an operational documentation change, and reliance on a manufacturer service bulletin as the normative work instruction. Applicability is narrow and enumerated, limited to Hawker 800XP aeroplanes with the serial numbers listed in the AD text. The AD binds those airframes to a sequence of technical interventions derived from Raytheon Service Bulletin SB 24-3555 Revision 1 dated June 2004; the AD does not itself contain the technical work instructions, it incorporates them by reference (Requirement 1, Requirement 2, Requirement 3).

The AD distinguishes between inspection, repair and modification work. A "detailed inspection" is defined in Note 1 as an "intensive examination" that may require cleaning, dedicated lighting and inspection aids such as mirrors and magnifying lenses. This definition sets an operational standard higher than a cursory visual check and signals expected labour and tool inputs for maintenance personnel. The AD prescribes repairs "in accordance with Part 1 of the Accomplishment Instructions of SB 24-3555 Rev 1" if damage is found; this ties the required corrective work to the manufacturer’s specified method, not to alternative repair standards within the AD text (Requirement 2).

Requirement 3 calls for a modification of the emergency radio circuit as detailed in Part 2 of the same SB. The compliance window for that modification is conditional on the inspection outcome. If inspection finds damage, the modification must be completed before further flight; if inspection finds no damage, the modification may be deferred up to 300 hours TIS or 180 calendar days after the AD’s effective date. This graded timing imposes immediate action on damaged aircraft but offers a deferred window for aircraft that pass inspection. Requirements 4 and 5 are follow-up operational checks and documentation changes, respectively, each required before further flight after the modification. The documentation action is specific: insert Temporary Change P/N 140-590032-0005TC7 into the "Aircraft Fight Manual Emergency Procedure" section (Requirement 5).

The AD explicitly references FAA AD 2005-09-03 Amdt 39-14071 (Note 2), indicating cross-jurisdictional awareness and that the FAA has addressed the same hazard. The AD’s background statement attributes the safety risk to "possible miswiring in the power distribution system," which the FAA advised may result in excessive current flow, smoke or fire (Background). The AD does not include the text of the Raytheon Service Bulletin, it instead mandates actions be carried out "in accordance with" Parts 1 and 2 of that SB. The effective date is stated as 1 June 2005, and the document is signed by a named delegate of the Civil Aviation Safety Authority (signature block).

The primary, explicit subjects of this Directive are owners, operators, and maintenance organisations responsible for the Hawker 800XP aeroplanes listed under Applicability: serial numbers 258541, 258556 and 258567 through 258608 inclusive. Those identified airframes are the only aircraft to which the AD applies as written, because the Applicability section lists specific serial numbers. Persons or entities with title or operational control of those airframes at the effective date must ensure the AD’s mandated actions are carried out within the prescribed timeframes (Applicability; Compliance).

Maintenance personnel and organisations engaged to perform the inspections, repairs and circuit modifications will be operationally affected, because the AD requires work "in accordance with Part 1/Part 2 of the Accomplishment Instructions of Raytheon Service Bulletin (SB) 24-3555, Revision 1 dated June 2004" (Requirement 1, Requirement 2, Requirement 3). The AD thereby requires access to and use of that specific service bulletin as the technical standard for performing the mandated tasks. Where the AD requires a "detailed inspection" and defines that term (Note 1), personnel will need to supply inspection aids, cleaning, and suitable lighting as part of the work scope.

Pilots and operators are also affected by the documentation amendment in Requirement 5, which requires insertion of Temporary Change P/N 140-590032-0005TC7 into the Aircraft Fight Manual Emergency Procedure section before further flight. That insertion modifies the procedures available to flight crews for emergency situations and must be in place after the modification (Requirement 5). The AD therefore imposes both physical maintenance obligations and an operational documentation change that influences flight crew briefings and emergency procedure availability.

Supply-chain and parts providers may be affected to the extent the SB specifies parts or configurations required for the emergency radio circuit modification. The AD requires the modification "as detailed in the Part 2 of the Accomplishment Instructions," which will normally entail specific parts and connectors; the AD text itself does not list those parts, therefore operators must obtain them by consulting SB 24-3555 Rev 1. Finally, regulators and certification authorities are implicated through issuance and the effective date, and the AD references a related FAA directive (Note 2), which may influence cross-border maintenance coordination for these aircraft types.

Who pays, in practical terms, will be the owners/operators of the affected aircraft, because the AD prescribes inspections, repairs, modification and documentation insertion as actions that must be completed within the specified timelines. The AD does not allocate costs or provide funding; the obligation to perform the work is stated as mandatory in the Requirements and Compliance sections.

The AD establishes several explicit duties, set out as Requirements 1 through 5, with associated compliance timing. Duty 1: perform a detailed inspection for wiring damage in the flight compartment, primarily for evidence of heat damage, following Part 1 of the Accomplishment Instructions of Raytheon SB 24-3555 Revision 1 (Requirement 1). The AD defines "detailed inspection" in Note 1, creating an expectation of a non-trivial level of inspection effort, including cleaning and use of inspection aids where necessary. Duty 2: if damage is found during that inspection, repair the wiring in accordance with Part 1 of the SB before further flight after the inspection (Requirement 2). Duty 3: modify the emergency radio circuit per Part 2 of the SB; timing for this duty is conditional , if damage was found, the modification must be completed before further flight; if no damage was found, the modification must be completed within 300 hours TIS or 180 calendar days after the AD’s effective date (Requirement 3). Duty 4: conduct a functionality check of the emergency radio system after the modification, before further flight (Requirement 4). Duty 5: revise the Aircraft Fight Manual Emergency Procedure section by inserting Temporary Change P/N 140-590032-0005TC7, to be completed before further flight after the modification (Requirement 5).

The AD does not articulate rights for addressees beyond the obligations to follow the specified procedures. It does not provide for alternatives to the Raytheon SB methods within the AD text, and it requires work to be done "in accordance with" the SB, which effectively constrains methods to those detailed in the incorporated Parts 1 and 2. The AD also does not specify appeals, exemptions, or a process for seeking alternative methods of compliance within its text. The absence of such procedures in the AD document means the listed duties are stated as direct commands without an embedded administrative exemption or alternative compliance pathway in the text provided.

Timing duties are explicit and binding as to the AD’s operational sequencing. The inspection is required "within 50 hours time in service (TIS) or 30 days, whichever occurs first, after the effective date of this Directive" (Compliance for Requirement 1). Repair, if needed, must be performed "before further flight after Requirement 1 inspection" (Compliance for Requirement 2). The conditional schedule for the modification is spelled out: "If damage was found during the Requirement 1 inspection - Before further flight after the inspection" and "If damage was not found during the Requirement 1 inspection - Within 300 hours TIS or 180 calendar days after the effective date of this Directive" (Compliance for Requirement 3). Functional check and AFM insertion are each required "Before further flight after the Requirement 3 modification is accomplished" (Compliance for Requirements 4 and 5).

The AD specifies the effective date, "This Airworthiness Directive becomes effective on 1 June 2005," which fixes the calendar reference point for all compliance timing (Effective date). The AD is issued under the authority of the Civil Aviation Safety Authority, and it is signed by a named delegate, James Coyne (signature block). The AD also references FAA AD 2005-09-03 Amdt 39-14071, which is noted but not incorporated as the operative instruction; the AD’s operative instructions are the Requirement and Compliance text plus the Raytheon SB references (Note 2).

The text of this Airworthiness Directive does not set out specific penalties, fines or enforcement procedures. It states required actions and compliance deadlines, and identifies the Civil Aviation Safety Authority as the issuing body with a named delegate, James Coyne, signing the document (signature block). The AD declares an effective date of 1 June 2005, and imposes mandatory technical and documentation actions tied to that effective date (Effective date; Compliance). The instrument expresses mandatory language in the Requirements, for example "Perform a detailed inspection" and "Modify Emergency Radio Circuit," which indicates obligations; however, the AD text itself contains no section that specifies criminal, civil or administrative sanctions for non-compliance, nor does it set out a process for reporting compliance to the regulator.

Because the AD is issued by the Civil Aviation Safety Authority, the practical enforcement context to be inferred from the document is that the responsible national aviation regulator has issued a binding airworthiness directive. The AD does not describe the regulator’s enforcement tools, inspection regimes, or certification consequences in the text provided. The AD’s reference to FAA AD 2005-09-03 Amdt 39-14071 (Note 2) shows regulatory alignment with the United States authority, but the AD does not articulate enforcement coordination or mutual recognition mechanisms.

The AD does define mandatory timing and "before further flight" milestones. Those milestones operate as operational constraints: until the required repairs, modification, functionality check and manual insertion are completed, the AD requires that affected aircraft not be returned to service or flown beyond the "before further flight" points. The AD’s text leaves unspecified the mechanism by which an operator proves compliance, such as submission of maintenance records to the regulator or entry in the aircraft logbook, although standard aviation practice outside this AD would ordinarily require recordkeeping. The AD itself does not command record retention or specify the form of evidence.

Practitioners should note that this AD contains clear operative obligations and an effective date; the AD does not, within the document, enumerate penalties or enforcement pathways. Any question about sanctions, remedial enforcement, or the process for seeking alternative compliance would need to be addressed by reference to the enabling legislation and enforcement procedures of the Civil Aviation Safety Authority or by contacting the Authority, since those matters are not set out in this Directive text.

The Directive expressly references a corresponding United States Federal Aviation Administration action, namely FAA AD 2005-09-03 Amdt 39-14071, by way of Note 2. That reference indicates the subject matter , possible miswiring in the power distribution system , has also been addressed by the FAA, and the AD records the FAA’s advisory role in identifying the safety issue (Background; Note 2). The AD’s operative instructions, however, do not incorporate the FAA AD text; rather the AD mandates compliance with specific parts of Raytheon Service Bulletin SB 24-3555 Revision 1 dated June 2004, as the technical standard for inspection, repair and modification (Requirements 1-3). Therefore, within the AD itself, the primary normative cross-reference is to the Raytheon SB, with the FAA AD noted as related material.

Beyond that explicit reference, the Directive contains no text that identifies how it modifies, overrides or interacts with other Australian statutory instruments, regulatory provisions, or civil aviation rules. The AD’s procedural commands , for example, "Perform a detailed inspection" and "Modify Emergency Radio Circuit" , function as mandatory airworthiness instructions for the aircraft specified. The AD does not state whether compliance with it satisfies any separate regulatory paperwork or certification obligations under other instruments, nor does it cite an enabling statute or procedural framework within the AD text itself.

The AD includes a requirement to revise the Aircraft Fight Manual Emergency Procedure section by inserting Temporary Change P/N 140-590032-0005TC7 (Requirement 5). That action directly affects aircraft documentation and therefore interacts operationally with any regulatory duties concerning aircraft flight manuals and emergency procedures. The AD does not elaborate on whether the temporary change requires separate approval, how it should be recorded, or the effect on approved flight manuals beyond the insertion instruction.

Because the AD imposes maintenance and documentation changes that condition return to service by setting "before further flight" requirements for several actions, it will interact in practice with maintenance certification regimes, aircraft logbook entries, and continuing airworthiness records that operators must keep under the broader civil aviation regulatory framework. Those interactions are not spelled out in this AD text; readers should consult the Civil Aviation Safety Authority’s regulatory materials for the specifics of maintenance release, logbook entries, and continuing airworthiness obligations. The AD’s note that the FAA issued a related AD indicates that operators who move these aircraft between jurisdictions may need to consider both instruments, but the AD does not specify cross-jurisdictional procedures.

The AD itself records only a limited amendment history within its text. It requires compliance "in accordance with Part 1 of the Accomplishment Instructions of Raytheon Service Bulletin (SB) 24-3555, Revision 1 dated June 2004" and references both Part 1 and Part 2 of SB 24-3555 Revision 1 for the mandated actions (Requirement 1, Requirement 2, Requirement 3). Thus the AD relies on a specific revision of the Raytheon Service Bulletin, Revision 1 dated June 2004, as the normative technical standard. The AD does not reference any earlier or later revisions of that SB within its text.

The AD itself becomes effective on 1 June 2005, and it is dated and signed by James Coyne as Delegate of the Civil Aviation Safety Authority on 12 May 2005 (Effective date; signature block). No subsequent amendments, supersessions or revocations are contained in the AD text provided. The AD does not include any history of prior AD versions for the same subject, nor does it indicate that it replaces or amends any earlier Australian AD. It does note an FAA counterpart, FAA AD 2005-09-03 Amdt 39-14071, as a related instrument (Note 2), but it does not state that the FAA AD amends or is amended by this AD.

Because the AD incorporates SB 24-3555 Revision 1, any later revision of the Raytheon service bulletin would not automatically alter the AD’s requirements unless the AD itself were amended to reference a new revision. The AD does not provide an incorporation-by-reference clause that allows substitution of later revisions, nor does it authorise an alternative method of compliance within the AD text. Therefore the Amendment history in the document is limited to the fact that the operative SB is Revision 1 dated June 2004 and the AD’s effective date is 1 June 2005. No further amendment history is presented in the source text.

Practitioners seeking to know whether later SB revisions or regulatory changes affect the AD must consult the Civil Aviation Safety Authority outside this AD text, since this document only sets the single point-in-time reference and effective date and does not include subsequent amendment entries.

The AD document contains no litigation history, court references, or adjudicative outcomes. It does not identify any legal proceedings, challenges, appeals, or decisions related to the Directive or its requirements. The text provides technical instructions, compliance timelines and the issuing authority’s delegate signature, but it does not record any disputes or litigation involving the AD, the Raytheon service bulletin SB 24-3555 Rev 1, or FAA AD 2005-09-03 Amdt 39-14071.

Because the AD includes no litigation history, readers cannot infer from the AD text whether any party has contested the mandate or whether enforcement actions have been litigated. The AD’s silence on litigation means that any record of legal challenge, administrative review, or court decision, if it exists, is not contained in this source and would need to be located through external records or the Civil Aviation Safety Authority’s archives.

The AD does identify its issuing authority and signatory , James Coyne, Delegate of the Civil Aviation Safety Authority , and it records the effective date and the FAA advisory background, but none of these elements includes litigation references. Practitioners interested in case law, disputes over the technical content, or enforcement litigation involving this AD must therefore consult external repositories, regulator publications or legal databases, because the AD text itself does not provide that information.

The AD contains several drafting and practical details that can cause operational or compliance confusion if not read carefully. First, applicability is limited to specific serial numbers , "Hawker 800XP aeroplanes serial numbers 258541, 258556 and 258567 through 258608 inclusive" , meaning a neighbouring serial number is not covered by this instrument. Do not assume broader model coverage; the AD’s Applicability section is explicit and narrow.

Second, the AD uses the phrase "detailed inspection" and provides a definition in Note 1: "An intensive examination ... A direct source of good lighting as well as inspection aids such as mirrors, magnifying lenses, etc., may be necessary. Surfaces may also be required to be cleaned." This elevates the expected inspection standard beyond a casual visual check. Maintenance teams must plan for additional labour, cleaning time, and inspection aids; failing to meet the "detailed inspection" standard may leave an operator non-compliant with Requirement 1.

Third, conformity is defined by reference to Raytheon SB 24-3555 Revision 1 dated June 2004. The AD mandates repairs "in accordance with Part 1" and the modification "as detailed in the Part 2" of that SB. The AD does not include the SB text, it requires parties to obtain and follow that SB. The AD does not expressly permit alternative repair methods or other data to be used in place of the SB. Practitioners should not assume that other procedures or later SB revisions are acceptable in the absence of an explicit allowance in the AD.

Fourth, the conditional nature of Requirement 3’s timing is a practical gotcha. If damage is found during Requirement 1, the modification must be performed "before further flight after the inspection." If no damage is found, the operator has a deferrable window "within 300 hours TIS or 180 calendar days after the effective date." Misreading which branch applies could result in an aircraft being flown without the modification where the AD requires immediate action.

Fifth, the AD requires insertion of "Temporary Change P/N 140-590032-0005TC7" in the Aircraft Fight Manual Emergency Procedure section. The AD text uses the phrase "Aircraft Fight Manual" which appears to be a typographical error in the Directive; the likely intended document is the Aircraft Flight Manual. The AD text, however, is the operative instrument and uses the phrase as given. Practitioners should ensure the temporary change is placed into the correct manual and section, but when communicating with the regulator or documenting compliance, preserve the AD’s quoted wording where necessary to avoid apparent discrepancy.

Sixth, the AD contains no explicit instructions about recordkeeping, maintenance release signatures, or submission of compliance evidence to the regulator. Standard airworthiness recordkeeping obligations are not recited in the AD text; operators should therefore align the AD work with their statutory maintenance release and logbook practices, but should not assume the AD itself provides recordkeeping instructions.

Seventh, the AD references FAA AD 2005-09-03 Amdt 39-14071 (Note 2). That reference is advisory in the AD text but could lead to assumptions that FAA compliance equals CASA compliance. The AD requires specific action "in accordance with" Raytheon SB 24-3555 Rev 1. Do not assume satisfying the FAA AD or following a different SB revision is sufficient without verifying the requirements are identical.

Finally, the AD gives a tight initial inspection window of "within 50 hours TIS or 30 days, whichever occurs first" after the effective date. Operators who do not plan maintenance slots in advance may struggle to meet that initial window. The AD does not provide an alternative method of compliance within its text.

To comply with this AD as written, follow the sequence and methods the AD specifies, and observe the stated compliance windows. Step 1, confirm applicability: verify the aircraft serial number is one of those listed in the Applicability section , 258541, 258556 and 258567 through 258608 inclusive. Only those airframes are subject to the AD’s mandates.

Step 2, obtain the normative documents: secure Raytheon Service Bulletin SB 24-3555 Revision 1 dated June 2004, and the Temporary Change P/N 140-590032-0005TC7 referenced for the Aircraft Fight Manual insertion. The AD requires inspections, repairs and modifications "in accordance with" Parts 1 and 2 of SB 24-3555 Rev 1, so those Parts are the operative technical instructions.

Step 3, perform Requirement 1: carry out a "detailed inspection for damage (primarily but not limited to evidence of heat damage) of wiring in the flight compartment in accordance with Part 1 of the Accomplishment Instructions of Raytheon Service Bulletin (SB) 24-3555, Revision 1 dated June 2004." Do this within 50 hours TIS or 30 days, whichever occurs first, following the AD's effective date. Follow Note 1's definition of detailed inspection, including cleaning surfaces as necessary and using direct lighting and inspection aids like mirrors or magnifying lenses.

Step 4, if damage is found during Step 3, perform Requirement 2: repair the wiring "in accordance with Part 1 of the Accomplishment Instructions of SB 24-3555 Rev 1" and complete that repair before further flight after the inspection.

Step 5, perform Requirement 3: modify the emergency radio circuit "as detailed in the Part 2 of the Accomplishment Instructions of SB 24-3555 Rev 1." If damage was found during Step 3, complete the modification before further flight after the inspection. If no damage was found, complete the modification within 300 hours TIS or 180 calendar days after the AD’s effective date. Schedule parts and maintenance resources accordingly.

Step 6, perform Requirement 4: after completing the modification in Step 5, conduct the functionality check of the emergency radio system before further flight.

Step 7, perform Requirement 5: revise the Aircraft Fight Manual Emergency Procedure section by inserting Temporary Change P/N 140-590032-0005TC7, to be done before further flight after the modification.

Additional practical compliance steps not explicitly stated but implied by the AD’s actions are to plan for labour and tooling consistent with a "detailed inspection," ensure maintenance staff are familiar with and have access to SB 24-3555 Rev 1, and obtain any parts specified in Part 2 of the SB for the emergency radio circuit modification. Keep maintenance records of the inspection, repairs, modification, functionality check and manual insertion, noting dates, personnel, and referenced SB Part numbers, since the AD imposes clear "before further flight" and dated deadlines; while the AD itself does not specify the form of records, typical airworthiness practice requires documentation of completed work.

If damage is found, treat the aircraft as unserviceable for further flight until repairs and the modification plus the functionality check and AFM update are completed, consistent with the AD’s "before further flight" language. Confirm that the Temporary Change P/N is correctly inserted into the flight manual emergency procedure section and retain evidence of that insertion.

Where uncertainty exists about the adequacy of a proposed repair method or parts, consult the Raytheon SB Part 1 and Part 2 text for technical detail. The AD does not provide an alternative method of compliance in its text; for any deviation from the SB, contact the Civil Aviation Safety Authority for guidance because the AD requires actions "in accordance with" the SB and does not itself authorise substitutes.

Finally, note the AD’s effective date of 1 June 2005 and ensure the compliance windows are calculated from that date as the AD prescribes. The AD’s signatory is noted as James Coyne, Delegate of the Civil Aviation Safety Authority, and the AD references FAA AD 2005-09-03 Amdt 39-14071 as related material; keep that cross-reference in mind if operating the aircraft internationally, but rely on SB 24-3555 Rev 1 and the AD’s Requirements and Compliance sections to meet the Australian AD obligations.