{"id":"F2006B09165","name":"AD/DHC-8/10 - Uncommanded Engine Power Roll Back","slug":"ad-dhc-8-10-uncommanded-engine-power-roll-back","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52899,"registerId":"commonwealth-F2006B09165-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/10 - Uncommanded Engine Power Roll Back","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)  \nBombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\nAD/DHC-8/10 Uncommanded Engine Power Roll Back 13/89\n\nApplicability: All DHC 8 Series aircraft Serial No’s 3 through 134 not incorporating de Havilland modification 8/0886.\n\nRequirement: To eliminate the potential for uncommanded engine power roll back following inadvertent selection of the MAX/RDC PWR switch, perform an electrical continuity check to ensure that the MAX/RDC PWR switch cannot incorrectly connect 28 VDC power to the Engine Electronic Fuel Control.\n\nNote: Canadian AD CF-89-13 and DHC SB 8-73-10 refer.\n\nBackground: One instance of uncommanded engine power roll back has been reported following inadvertent crew selection of the MAX/RDC PWR switch. Investigation determined that the roll back resulted from 28 VDC being incorrectly fed to the Engine Electronic Control unit when the MAX/RDC PWR switch was inadvertently selected. The cause was traced to a 28 VDC wire which had mistakenly been connected to the MAX/RDC PWR switch during manufacture.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific manufacturing defect in specific aircraft. It has not expanded beyond its original purpose of preventing uncommanded engine power loss."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined term implicitly used (MAX/RDC PWR switch — explained in context)","Single, clear requirement with no nested conditions or exceptions","No cross-references to other legislation sections (only references to related Canadian AD and manufacturer service bulletin for information)","Straightforward applicability test (serial number range plus one modification exemption)"],"plain_english_summary":"This AD from CASA requires operators of certain Bombardier DHC‑8 (Dash 8) aeroplanes to perform an electrical continuity check of the MAX/RDC PWR switch to verify wiring isn’t incorrectly connected.  \n\nA manufacturing error can let that switch inadvertently cut engine power (an uncommanded power rollback). It affects serials 3–134 unless already modified (de Havilland mod 8/0886)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive targets the specific manufacturing miswiring that allowed 28 VDC to be incorrectly fed to the Engine Electronic Control and limits action to serial numbers 3–134 without mod 8/0886 (Applicability; Background). It does not expand to other models or broader systems beyond the stated check (Requirement)."},"complexity_factors":["Narrow fleet applicability — only DHC‑8 Serial Nos 3–134 not incorporating mod 8/0886 (Applicability).","Single technical task: electrical continuity check to verify the MAX/RDC PWR switch cannot connect 28 VDC to the Engine Electronic Fuel Control (Requirement).","Root-cause is a manufacturing wiring error, so inspection may require access to wiring and proof of modification status (Background).","Operators must perform the check (Requirement), so costs are borne by aircraft owners/operators.","External references (Canadian AD CF-89-13 and DHC SB 8-73-10) may require consulting additional documents to complete corrective action (Note)."],"plain_english_summary":"This airworthiness directive requires an electrical continuity check so the MAX/RDC PWR switch cannot mistakenly feed 28 VDC to the Engine Electronic Fuel Control. It applies to DHC‑8 Series aeroplanes Serial Nos 3–134 that have not had de Havilland modification 8/0886 and aims to prevent uncommanded engine power rollback traced to a miswired 28 VDC connection during manufacture."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-10-uncommanded-engine-power-roll-back","history":"/api/acts/ad-dhc-8-10-uncommanded-engine-power-roll-back/history","analysis":"/api/acts/ad-dhc-8-10-uncommanded-engine-power-roll-back/analysis","conflicts":"/api/acts/ad-dhc-8-10-uncommanded-engine-power-roll-back/conflicts","importantCases":"/api/acts/ad-dhc-8-10-uncommanded-engine-power-roll-back/important-cases","documents":"/api/acts/ad-dhc-8-10-uncommanded-engine-power-roll-back/documents"}}