{"id":"F2005L03936","name":"AD/DO 328/25 - Propeller Control Unit Bearing","slug":"ad-do-328-25-propeller-control-unit-bearing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":39776,"registerId":"commonwealth-F2005L03936-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Dornier 328 Series Aeroplanes","sectionType":"division","heading":"Dornier 328 Series Aeroplanes","content":"### Dornier 328 Series Aeroplanes\n\n| AD/DO 328/25 | Propeller Control Unit Bearing | 1/2006 |\n| ------------ | ------------------------------ | ------ |\n\n| Applicability: | Dornier 328-100 equipped with Propeller Control Unit (PCU 1-170A) P/N D-1199-2 having a serial number up to and including PCU-A-EFS379.                                                                                                                                                                                                                         |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Inspect the PCU or maintenance documentation for incorporation of Hartzell SBHD-SB-61-012. If the SB has been incorporated no further action is required. If the SB is not incorporated, comply with Hartzell SB HD-SB-61-012.Note 1: Dornier 328 Service Bulletin No. 328-61-221 R1dated 11 June 1997 pertains to this subject.Note 2: LBA AD 97-191/2 refers. |\n| Compliance:    | Within 30 days after the effective date of this AD.                                                                                                                                                                                                                                                                                                             |\n|                | This Airworthiness Directive becomes effective on 19 January 2006.                                                                                                                                                                                                                                                                                              |\n| Background:    | This AD requires the modification of the PCU to ensure that premature bearing failure does not occur.                                                                                                                                                                                                                                                           |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n30 November 2005","sortOrder":0},{"sectionNumber":"AD/DO 328/25","sectionType":"part","heading":"AD/DO 328/25","content":"## AD/DO 328/25","sortOrder":1},{"sectionNumber":"Propeller Control Unit Bearing","sectionType":"part","heading":"Propeller Control Unit Bearing","content":"## Propeller Control Unit Bearing","sortOrder":2},{"sectionNumber":"1/2006","sectionType":"part","heading":"1/2006","content":"## 1/2006","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD implements a targeted corrective measure to address premature bearing failure in the specified PCU units. It does not widen applicability beyond the stated model/part/serial range and confines obligations to inspection/documentation or SB incorporation as described (Applicability; Requirement; Background)."},"complexity_factors":["Narrow applicability (specific airframe model and PCU P/N and serial-number cap) (Applicability)","Single, well-defined corrective path: inspect for SB incorporation or perform Hartzell SB HD‑SB‑61‑012 (Requirement)","Short compliance window: 30 days after AD effective date (Compliance)","References to external documents and foreign AD: Hartzell SB HD‑SB‑61‑012, Dornier SB 328‑61‑221 R1, LBA AD 97‑191/2 (Requirement)","Operational impacts on operators/maintenance providers: labour, parts, and aircraft downtime (Requirement; Background)","Recordkeeping/documentation check required (Requirement)","Low regulatory discretion — mandatory AD with set effective date (Compliance)"],"plain_english_summary":"This Airworthiness Directive requires operators of Dornier 328‑100 aeroplanes fitted with Propeller Control Unit (PCU 1‑170A) P/N D‑1199‑2 (serial numbers up to and including PCU‑A‑EFS379) to inspect the PCU or maintenance records for incorporation of Hartzell Service Bulletin HD‑SB‑61‑012 and, if not incorporated, to carry out that SB. Compliance is mandatory within 30 days and the AD is effective 19 January 2006.\n\nThe stated purpose is to prevent premature bearing failure; operators and maintenance providers bear inspection, retrofit, documentation and downtime costs (Applicability; Requirement; Compliance; Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive targeting a specific mechanical defect in a specific aircraft component. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 200 words of substantive content)","Only 1 defined term implied (PCU = Propeller Control Unit, expanded in the text)","Single conditional requirement: check if modification done → if yes, stop; if no, do it","No nested exceptions or complex cross-referencing structure","References to external technical documents (Hartzell SB HD-SB-61-012 and Dornier Service Bulletin) but does not incorporate their text","Clear, linear compliance pathway with single deadline"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's aviation regulator (CASA) that requires specific aircraft owners or operators to take action to fix a known safety problem.\n\n**What it does:**\n- Requires owners/operators of specific **Dornier 328-100 aircraft** to check whether a particular safety modification has already been made to the **Propeller Control Unit (PCU)** — a component that controls the aircraft's propellers.\n- If the modification (described in a Hartzell service bulletin) has **already been done**, no further action is needed.\n- If the modification has **not been done**, the owner/operator must carry it out.\n\n**Who it affects:**\n- Operators of Dornier 328-100 aircraft fitted with a specific model of Propeller Control Unit (PCU 1-170A, part number D-1199-2) with serial numbers up to PCU-A-EFS379.\n\n**Why it matters:**\n- The modification prevents **premature bearing failure** in the propeller control system. If the bearing fails, it could cause loss of propeller control, potentially leading to an accident.\n- Compliance is **mandatory** and must be completed within **30 days** of the directive taking effect (19 January 2006).\n\n**Key point:** This is a \"one-time check and fix if needed\" safety order designed to catch a specific mechanical defect before it causes problems in flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-do-328-25-propeller-control-unit-bearing","history":"/api/acts/ad-do-328-25-propeller-control-unit-bearing/history","analysis":"/api/acts/ad-do-328-25-propeller-control-unit-bearing/analysis","conflicts":"/api/acts/ad-do-328-25-propeller-control-unit-bearing/conflicts","importantCases":"/api/acts/ad-do-328-25-propeller-control-unit-bearing/important-cases","documents":"/api/acts/ad-do-328-25-propeller-control-unit-bearing/documents"}}