{"id":"F2006B10990","name":"AD/JT8D/36 - Compressor Disks","slug":"ad-jt8d-36-compressor-disks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56579,"registerId":"commonwealth-F2006B10990-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JT8D/36 - Compressor Disks","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPratt and Whitney Turbine Engines \\- JT8D Series\n\nAD/JT8D/36 Compressor Disks 2/99\n\nApplicability: Pratt and Whitney JT8D series engines that have a compressor disk installed identified by part and serial number in Table 1 of FAA AD 98-21-24.\n\nRequirement: Inspect affected compressor disks in accordance with the technical requirements of FAA AD 98-21-24.\n\nNote: GE Engine Services \\- Dallas, LP, Engineering Bulletin (EB) JT8D-025, dated 27 March 1998 also refers.\n\nCompliance: At the next shop visit, or within 3000 cycles in service after the effective date of this Directive, or within 10 years after the effective date of this Directive, whichever occurs first.\n\nThis Airworthiness Directive becomes effective on 25 February 1999.\n\nBackground: This airworthiness directive is prompted by reports of improper fixturing during the electrolytic cleaning of certain compressor discs that can result in arc burns in disk tiebolt holes, pressure balance holes and shielding holes. Arc burns in these areas could lead to a disk fracture and uncontained engine failure.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific manufacturing defect in specific engine models. It has not expanded beyond its original purpose of mandating inspections for arc burn damage in JT8D compressor disks."},"complexity_factors":["Short, single-purpose directive (approximately 200 words)","Only 4 defined elements: applicability, requirement, compliance, and background","Single cross-reference to FAA AD 98-21-24 for technical details (avoids reproducing complex engineering specifications)","Simple conditional compliance structure with three alternative deadlines ('whichever occurs first')","No nested exceptions or sub-delegations","Technical content is incorporated by reference rather than included in the text"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspection of certain Pratt & Whitney JT8D compressor disks (as identified in FAA AD 98-21-24) because improper electrolytic cleaning caused arc-burn damage that can produce cracks and lead to catastrophic uncontained engine failure. It affects operators of JT8D-powered aircraft (e.g., older 737-100/200 and DC‑9/MD‑80). Inspections must follow the FAA instructions and meet the required timing options."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive confines action to compressor disks identified by part and serial number in FAA AD 98-21-24 and requires inspections per that FAA AD. It does not expand to other engine models or unlisted parts; it implements targeted inspections to address reported arc-burn damage and the resulting fracture risk."},"complexity_factors":["Cross-reference dependency: mandatory compliance with the technical requirements of FAA AD 98-21-24 rather than full self-contained procedures increases reliance on external document (Applicability/Requirement).","Narrow applicability: only JT8D engines with compressor disks listed by part and serial number in FAA AD Table 1 are affected (Applicability).","Multiple compliance triggers: next shop visit OR within 3,000 cycles OR within 10 years, whichever first, creates scheduling flexibility but requires tracking (Compliance).","Operational burden: inspections will consume shop time and may lead to repair/disposition work and associated costs borne by operators/maintenance organisations (Requirement/Compliance).","Technical ambiguity risk: inspection and disposition depend on FAA technical directions and referenced GE Engineering Bulletin, requiring technical judgement and access to those documents (Requirement/Note).","Safety consequence linkage: directive responds to specific reported failure mode (arc burns in tiebolt, pressure-balance and shielding holes) that can cause disk fracture and uncontained engine failure, which elevates enforcement and record-keeping importance (Background).","Administrative effect: directive has an effective date (25 February 1999) that creates a clear legal start for compliance monitoring (Compliance/Effective date)."],"plain_english_summary":"This Airworthiness Directive requires operators of Pratt & Whitney JT8D engines that have specific compressor disks (identified by part and serial number in FAA AD 98‑21‑24) to inspect those disks using the FAA’s technical requirements. Inspections must be done at the next shop visit or within 3,000 cycles in service, or within 10 years, whichever is earlier. The directive places compliance responsibility on operators and maintenance organisations and responds to reports of arc burns that can lead to disk fracture and uncontained engine failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jt8d-36-compressor-disks","history":"/api/acts/ad-jt8d-36-compressor-disks/history","analysis":"/api/acts/ad-jt8d-36-compressor-disks/analysis","conflicts":"/api/acts/ad-jt8d-36-compressor-disks/conflicts","importantCases":"/api/acts/ad-jt8d-36-compressor-disks/important-cases","documents":"/api/acts/ad-jt8d-36-compressor-disks/documents"}}