{"id":"F2006B09210","name":"AD/DHC-8/54 Amdt 2 - Fuselage Cable Trough","slug":"ad-dhc-8-54-amdt-2-fuselage-cable-trough","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53047,"registerId":"commonwealth-F2006B09210-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/54 Amdt 2 - Fuselage Cable Trough","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n![](image.002.png)  \nBombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/DHC-8/54 Amdt 1 and issues the following 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.\n\nAD/DHC-8/54\n\nAmdt 2\n\n  \nFuselage Cable Trough 10/2000\n\nApplicability: DHC-8 aeroplanes Models 102, 103, 106, 201, 202, 301, 311, 314 and 315 with serial\n\nnumbers 3 through 540 inclusive, excluding serial number 462.\n\nRequirement: Inspect the wiring in the underfloor cable trough and incorporate Bombardier Modification 8/2705 in accordance with the following Bombardier Inc de Havilland Dash 8 Service Bulletins:\n\n| Model                      | Service Bulletin  | Date of Issue                     |\n| -------------------------- | ----------------- | --------------------------------- |\n| 102, 103, 106, 201 and 202 | 8-53-66and8-53-80 | 27 March 1998 and22 December 1999 |\n| 301, 311, 314 and 315      | 8-53-66           | 27 March 1998                     |\n\nNote: Transport Canada AD CF-98-08 R2 refers.\n\nCompliance: The compliance remains unchanged as ‘At the next ‘C’ check, but no later than 36 months after 18 June 1998 (the effective date of the original issue of this Directive)’.\n\nThis Amendment becomes effective on 5 October 2000.\n\nBackground: A DHC-8 aeroplane experienced an uncommanded engine shut-down in flight due to a short circuit between adjacent wires located in the left underfloor cable trough. The short circuit resulted in a 28 volt signal being applied to the fuel shut-off valve. An investigation revealed that the short circuit was caused by chafing of wires on sharp edges on the cherrymax rivets in the cable trough.\n\nThis Directive requires inspection of the wiring in the underfloor cable trough together with the installation of new cable tie-mounts in the cable trough and sealing rivets to prevent chafing of wires.\n\nAmendment 1 increased the serial number range of the affected aeroplanes.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nThis amendment addresses the omission of a section of the underfloor cable trough in the instructions for inspecting the wires and for incorporating Modification 8/2705 in model 102, 103, 106, 201 and 202 aeroplanes.\n\n![](image.003.png)  \nThe original issue of this Airworthiness Directive became effective on 18 June 1998. Amendment 1 of this Airworthiness Directive became effective on 3 December 1998.\n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 25 August 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 6 September 2000.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 2 does not broaden the substantive scope of the original Directive. It is a technical correction that fixes an omission in the inspection/modification instructions for certain models; the affected models, serial number range (as amended previously), required modification (Mod 8/2705) and the compliance deadline remain unchanged. In short, the instrument clarifies the required work rather than expanding who or what is regulated."},"complexity_factors":["Short, single‑issue AD focused on one physical area (underfloor cable trough).","Applicability list covers 9 aircraft models and a serial range (3–540) with one explicit exclusion (serial 462).","Cross‑references to multiple Bombardier Service Bulletins (different SBs by model) and to a Transport Canada AD.","Compliance timing uses relative deadline language (next ‘C’ check but no later than 36 months after 18 June 1998), requiring attention to maintenance scheduling and historical dates.","Technical correction/amendment history (original AD, Amendment 1 expanded serial range, Amendment 2 fixes omitted inspection section) — minor procedural complexity.","Requires incorporation of a specific manufacturer modification (8/2705) — dependence on external technical documents rather than self‑contained instructions."],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- It requires operators of certain Bombardier (De Havilland) DHC‑8 (Dash 8) aeroplanes to inspect wiring in the left underfloor cable trough and to carry out Bombardier Modification 8/2705 (install new cable‑tie mounts and seal rivets) in accordance with specified Bombardier Service Bulletins.\n- The models covered are DHC‑8 102, 103, 106, 201, 202, 301, 311, 314 and 315 with serial numbers 3 through 540 inclusive, except serial number 462.\n- The work must be done at the next scheduled ‘‘C’’ check, but no later than 36 months after 18 June 1998 (the effective date of the original directive).\n- The Directive revokes the prior Amendment 1 and issues Amendment 2 to correct an omission in the inspection/modification instructions for models 102, 103, 106, 201 and 202.\n\n**Why CASA required this (stated reason)**\n\n- An in‑flight uncommanded engine shutdown occurred after a short circuit between adjacent wires in the left underfloor cable trough. The short was caused by wire chafing on sharp edges of cherrymax rivets, and it applied a 28‑volt signal to a fuel shut‑off valve. The Directive is intended to remove the chafing risk by inspection, sealing rivets and adding cable‑tie mounts.\n\n**Who is affected and who pays**\n\n- Affected parties: operators/owners of the listed DHC‑8 aeroplane serials, their maintenance organisations (including independent MROs), and potentially parts suppliers for tie mounts and rivet seals.\n- Who pays: aircraft operators incur the cost of inspection, parts and labour to perform Modification 8/2705. The work is to be done during a ‘‘C’’ check so operators will primarily bear scheduling and downtime costs tied to that maintenance event.\n\n**How it changes behaviour and contracting**\n\n- Operators must schedule the inspection/modification into their next ‘‘C’’ check (or sooner if they prefer) and follow the Bombardier Service Bulletin instructions cited in the AD.\n- Use of the manufacturer’s Service Bulletins means the work must meet those technical specifications; independent maintenance providers can perform the work provided they comply with the SB and regulatory oversight. The AD is mandatory (not optional guidance).\n\n**Costs, incentives and trade‑offs**\n\n- The Directive reduces the chance of electrical shorts and related safety events (concentrated safety benefit for affected operators and passengers).\n- Costs are concentrated on affected operators (inspection time, parts, labour, scheduling). Because the compliance timing is linked to an existing ‘‘C’’ check and a 36‑month window, the AD reduces the incentive for operators to schedule an additional maintenance visit, lowering incremental costs but fixing a firm deadline.\n- Opportunity cost: a ‘‘C’’ check slot must be used for this work, which could displace other optional maintenance or modifications.\n\n**Implementation, compliance burden and risks**\n\n- Compliance depends on following the cited Bombardier Service Bulletins (specific SB numbers and dates are given), and on accurate identification of serial numbers.\n- Amendment 2 is a technical correction of the inspection instructions; that lowers implementation risk by ensuring the correct area of the cable trough is inspected and modified.\n- CASA delegates issued and enforces the AD; enforcement and interpretation rely on CASA’s administrative processes and accepted maintenance records.\n\n**Other practical points**\n\n- The Directive cross‑references a Transport Canada AD (CF‑98‑08 R2) and Bombardier Service Bulletins for the exact technical method—operators will have to obtain and follow those documents.\n- The AD excludes one serial number (462), so affected operators must check serials precisely to determine applicability.\n\n(References in the Directive: Bombardier Modification 8/2705; Bombardier Service Bulletins 8‑53‑66 and 8‑53‑80; Transport Canada AD CF‑98‑08 R2; compliance timing tied to 18 June 1998.)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains tightly scoped to its original purpose — fixing the wiring chafing issue in DHC-8 aircraft. Amendment 2 is purely corrective, addressing only an omission in the inspection instructions for certain models. It does not expand the aircraft types affected, add new requirements, or broaden the safety issue addressed."},"complexity_factors":["Multiple aircraft models and serial numbers create applicability conditions","References to external technical documents (Bombardier Service Bulletins 8-53-66 and 8-53-80) without reproducing their content","Cross-reference to Canadian aviation regulation (Transport Canada AD CF-98-08 R2)","Nested effective dates and compliance deadlines (original issue, Amendment 1, Amendment 2)","Technical aviation terminology requiring domain knowledge (e.g., 'C check', 'cherrymax rivets', 'cable trough')"],"plain_english_summary":"This airworthiness safety order requires operators of Bombardier DHC‑8 (Dash 8) Series 100/200/300 aircraft to inspect and remediate underfloor cable‑trough wiring chafing that can short and inadvertently shut down an engine. Affected airplanes: models 102, 103, 106, 201, 202, 301, 311, 314, 315, S/N 3–540 (except 462). Work (install tie‑mounts and seal rivets per Bombardier service bulletins) must be done by the next C check or within 36 months of 18 June 1998. Amendment 2 corrects an earlier omission so the full trough is covered."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-54-amdt-2-fuselage-cable-trough","history":"/api/acts/ad-dhc-8-54-amdt-2-fuselage-cable-trough/history","analysis":"/api/acts/ad-dhc-8-54-amdt-2-fuselage-cable-trough/analysis","conflicts":"/api/acts/ad-dhc-8-54-amdt-2-fuselage-cable-trough/conflicts","importantCases":"/api/acts/ad-dhc-8-54-amdt-2-fuselage-cable-trough/important-cases","documents":"/api/acts/ad-dhc-8-54-amdt-2-fuselage-cable-trough/documents"}}