{"id":"F2006B06217","name":"AD/PHZL/56 - Pitch Change Rod","slug":"ad-phzl-56-pitch-change-rod","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47118,"registerId":"commonwealth-F2006B06217-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PHZL/56 - Pitch Change Rod","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPropellers \\- Variable Pitch \\- Hartzell\n\nAD/PHZL/56 Pitch Change Rod 10/87\n\nApplicability: All Hartzell propeller models HC-B4(T,M)N-5( ) fitted with either B-3018S-2 or B- 3018T-2 pitch change rods.\n\nNote: HC-B4(T,M)N-5 propellers are installed on Garrett TPE-331 turboprop engines. The affected propellers are installed on but not limited to : Dornier DO-228 ( ), Mitsubishi MU-2-( ), Swearingen SA-226, CASA C-212-( ), Beech B100 and Shorts SC-7.\n\nRequirement: Action in accordance with Hartzell Service Bulletin No. 153.\n\nCompliance: At next overhaul after 30 September 1987 or before 30 September 1988 whichever occur first.\n\nBackground: The four bladed steel hub propeller type used on Garrett powered installations has experienced failure of the pitch change rod P/N B-3018S-2. Failure of this rod has occurred during ground operation with application of full reverse pitch. Rod failure in this position will cause the propeller to travel deeper into reverse which could cause severe asymmetric thrust conditions or unacceptable engine over temperature conditions.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive applies to a defined set of propeller models and two specific pitch‑change rod part numbers and mandates work per a named service bulletin within a fixed compliance window. Nothing in the text indicates an expansion or narrowing of that original applicability or intent."},"complexity_factors":["Narrow technical applicability: specific propeller model and two part‑numbers (Applicability).","Mandated corrective action references an external document (Hartzell Service Bulletin No.153) rather than prescribing step‑by‑step work (Requirement).","Time‑limited compliance window that must be tracked by operators/maintenance organisations (Compliance).","Clear safety risk motivating the directive—rod fracture under full reverse leading to asymmetric thrust/engine over‑temperature (Background).","Potential operational cost/compliance burden falls on aircraft owners/operators at overhaul; enforcement and method depend on maintenance organisations following the service bulletin (Requirement/Compliance)."],"plain_english_summary":"This airworthiness directive orders operators of Hartzell HC-B4(T,M)N-5 propellers fitted with pitch change rods P/N B-3018S-2 or B-3018T-2 (used on Garrett TPE‑331 installations) to carry out the work set out in Hartzell Service Bulletin No.153 at their next overhaul between 30 Sep 1987 and 30 Sep 1988. It responds to reported failures of the pitch change rod under full reverse, which can drive the propeller deeper into reverse and create asymmetric thrust or engine over‑temperature risks."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical failure mode. It has not expanded beyond its original purpose of mandating inspection/replacement of defective pitch change rods in identified propeller models."},"complexity_factors":["Single, specific mechanical defect addressed with clear part number identification","Straightforward applicability criteria based on propeller model and component part numbers","Simple compliance deadline structure (next overhaul after fixed date OR fixed calendar date, whichever first)","No nested exceptions, conditional logic, or cross-references to other legislation beyond a single service bulletin","Minimal defined terms (only standard aviation abbreviations like P/N for part number)","Short document (approximately 200 words) with single purpose"],"plain_english_summary":"Owners/operators of certain Hartzell HC-B4(T,M)N-5 propellers (with pitch change rods B-3018S-2 or B-3018T-2) must inspect or replace those rods per Hartzell Service Bulletin No. 153. Cracked rods can fail during full ground reverse, producing asymmetric reverse thrust and risking loss of control or engine damage.\n\nApplies to twin-turboprops like Dornier DO-228, Mitsubishi MU-2, Swearingen SA-226, CASA C-212, Beech B100 and Shorts SC-7; work due at next overhaul after 30 Sep 1987 or by 30 Sep 1988."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-56-pitch-change-rod","history":"/api/acts/ad-phzl-56-pitch-change-rod/history","analysis":"/api/acts/ad-phzl-56-pitch-change-rod/analysis","conflicts":"/api/acts/ad-phzl-56-pitch-change-rod/conflicts","importantCases":"/api/acts/ad-phzl-56-pitch-change-rod/important-cases","documents":"/api/acts/ad-phzl-56-pitch-change-rod/documents"}}