{"id":"F2005L03957","name":"AD/DO 328/8 - Proximity Switch Electrical Unit","slug":"ad-do-328-8-proximity-switch-electrical-unit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":39824,"registerId":"commonwealth-F2005L03957-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 328/8 | Proximity Switch Electrical Unit | 1/2006 |\n| ----------- | -------------------------------- | ------ |\n\n| Applicability: | Model 328-100 aeroplanes all serial numbers equipped with a landing gear proximity switch electrical unit (PSEU) part number (P/N) 8-700-03 or 8-700-04 installed.                                                                                                                                                                            |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | If not previously accomplished, remove PSEUs P/N 8-700-03 or 8-700-04 and install a new PSEU P/N 8-700-04 Mod A in accordance with the Accomplishment Instructions of Dornier Service Bulletins SB-328-32-248 Revision 1 dated22 April 1998.                                                                                                  |\n|                | Note 1: For operators removing a P/N 8-700-03 unit, Dornier SB-328-32-143 must be performed prior to installation of a new unit.                                                                                                                                                                                                              |\n|                | Note 2: A new PSEU P/N 8-700-05 may be installed as an alternate to the installation of a PSEU P/N 8-700-04 Mod A.                                                                                                                                                                                                                            |\n|                | Note 3: LBA AD 1998-137/2 refers.                                                                                                                                                                                                                                                                                                             |\n| Compliance:    | Within 30 days after the effective date of this Directive.                                                                                                                                                                                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 19 January 2006.                                                                                                                                                                                                                                                                            |\n| Background:    | The German Luftfahrt-Bundesamt (LBA) has received reports of intermittent shutoff of control circuits within the PSEU preventing, in some instances, normal extension of the landing gear. Investigations have determined the cause to be a manufacturing fault within the PSEU. This Directive requires the replacement of the faulty PSEUs. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n29 November 2005","sortOrder":0},{"sectionNumber":"AD/DO 328/8","sectionType":"part","heading":"AD/DO 328/8","content":"## AD/DO 328/8","sortOrder":1},{"sectionNumber":"Proximity Switch Electrical Unit","sectionType":"part","heading":"Proximity Switch Electrical Unit","content":"## Proximity Switch Electrical Unit","sortOrder":2},{"sectionNumber":"1/2006","sectionType":"part","heading":"1/2006","content":"## 1/2006","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive enforces replacement only for the identified faulty PSEU part numbers on Model 328-100 aeroplanes and does not broaden applicability beyond those aircraft or components; it implements a corrective action consistent with the stated airworthiness concern (Applicability; Requirement; Background)."},"complexity_factors":["Narrow technical applicability limited to Model 328-100 aeroplanes with PSEU P/N 8-700-03 or 8-700-04 (Applicability)","Single clear corrective action: replace with P/N 8-700-04 Mod A or alternate P/N 8-700-05 (Requirement, Note 2)","Short compliance timeframe: mandatory within 30 days of effective date (Compliance)","Pre-installation procedural dependency when removing a specific part: must perform Dornier SB-328-32-143 before installing a new unit if removing P/N 8-700-03 (Requirement, Note 1)","Cross-reference to foreign authority and earlier service material (LBA AD 1998-137/2; Dornier SB-328-32-248 Rev 1) which operators must consult (Requirement, Note 3; Requirement)","Operational impacts include parts availability, labour and aircraft downtime but no ongoing monitoring regime set out (Background; Compliance)"],"plain_english_summary":"This Directive requires operators of Dornier 328-100 aeroplanes fitted with landing gear Proximity Switch Electrical Units (PSEU) P/N 8-700-03 or 8-700-04 to replace them with P/N 8-700-04 Mod A (or optionally P/N 8-700-05) within 30 days, because reported manufacturing faults can intermittently shut off control circuits and may prevent normal landing-gear extension. Operators must follow Dornier service instructions (including a preparatory service bulletin when removing P/N 8-700-03). Operators pay for parts, labour and downtime; CASA enforces compliance."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive targeting a specific safety defect in specific aircraft. It has not expanded beyond its original purpose of mandating replacement of faulty PSEUs."},"complexity_factors":["Very short document (approximately 250 words)","Only 2 defined part numbers with specific modification states","Single primary requirement with 3 straightforward notes","No cross-references to other legislation or complex conditional logic","Clear, unambiguous compliance deadline","Simple applicability test (specific aircraft model + specific part numbers)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's aviation regulator (CASA) for specific aircraft.\n\n**What it does:**\n- Orders owners/operators of certain **Dornier 328-100 aeroplanes** to replace faulty **Proximity Switch Electrical Units (PSEUs)** — these are components that help control the landing gear.\n- Specifically targets units with part numbers **8-700-03 or 8-700-04**, which have a manufacturing defect that can cause the landing gear to fail to extend properly.\n\n**Who it affects:**\n- Anyone operating a Dornier 328-100 aircraft with the affected PSEU part numbers installed.\n\n**What must be done:**\n- Remove the faulty PSEU and install a modified replacement unit (P/N 8-700-04 Mod A) following specific manufacturer instructions.\n- Alternative: A different part number (P/N 8-700-05) can be used instead.\n- Special note: If removing the older P/N 8-700-03 unit, an additional service bulletin must be completed first.\n\n**When:**\n- Within 30 days of 19 January 2006 (so by mid-February 2006).\n\n**Why it matters:**\n- The faulty units can cause **intermittent failure of landing gear extension** — a serious flight safety issue. This directive prevents potential accidents by forcing replacement of defective components before they fail."}},"importantCases":[],"_links":{"self":"/api/acts/ad-do-328-8-proximity-switch-electrical-unit","history":"/api/acts/ad-do-328-8-proximity-switch-electrical-unit/history","analysis":"/api/acts/ad-do-328-8-proximity-switch-electrical-unit/analysis","conflicts":"/api/acts/ad-do-328-8-proximity-switch-electrical-unit/conflicts","importantCases":"/api/acts/ad-do-328-8-proximity-switch-electrical-unit/important-cases","documents":"/api/acts/ad-do-328-8-proximity-switch-electrical-unit/documents"}}