{"id":"F2006B05769","name":"AD/PA-31/65 - Cabin Door Latch - Modification","slug":"ad-pa-31-65-cabin-door-latch-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135628,"registerId":"commonwealth-F2006B05769-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/65 - Cabin Door Latch - Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Piper PA-31 Series Aeroplanes\n\n \n\nAD/PA-31/65 Cabin Door Latch - Modification 5/78\n\nApplicability: All models PA-31, PA-31-325 and PA-31-300 with S/Nos. 31-2 to 31-7512029. All model PA-31-350 with S/Nos. 31-5001 to 31-7552052. Except those incorporating three kits denoted in Piper SL 739.\n\n \n\nDocument: Piper SL 803A.\n\n \n\nCompliance: Unless already accomplished, within 100 hours time in service after 31 May 1978.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive, as presented, specifies which aircraft are covered, an exclusion for aircraft with kits identified in Piper SL 739, the service document to use (Piper SL 803A), and a deadline (100 hours TIS after 31 May 1978). The source text contains no indication that the applicability, exclusions, or compliance timing have been altered from the directive's operative content; therefore there is no evidence in this text that the scope has changed from its stated content."},"complexity_factors":["Narrow and explicit applicability by model and serial number ranges (low complexity to identify affected aircraft). (Applicability)","Clear compliance deadline (100 hours TIS after 31 May 1978) reduces ambiguity. (Compliance)","Technical procedure is external to the text and referenced by Piper SL 803A, creating a dependency on a separate document for details. (Document: Piper SL 803A)","Exemption clause for aircraft with any of three kits in Piper SL 739 requires operators to verify aircraft configuration against another external document. (Applicability)","No procedural detail or rationale within the AD text itself requires users to consult the referenced service letter for implementation specifics. (Document: Piper SL 803A)"],"plain_english_summary":"This AD mandates a cabin-door latch modification for specified Piper PA‑31 series aeroplanes, to be performed per Piper Service Letter 803A. Owners/operators of the affected serial-number ranges must complete the work within 100 hours TIS after 31 May 1978 unless the aircraft already has one of the three kits listed in Piper SL 739. Compliance (parts, labour, downtime, and sourcing SL 803A) is the operator’s responsibility."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive focused on a single mechanical modification. It has not expanded beyond its original purpose of addressing cabin door latch safety in specific Piper aircraft models."},"complexity_factors":["Very short document (under 200 words)","Only 4 defined elements: applicability range, document reference, compliance deadline, and exception clause","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Single condition (the three-kit exception in Piper SL 739)","Clear, unambiguous compliance deadline with simple time-in-service calculation"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires aircraft owners to fix a specific mechanical problem.\n\n**What it does:** It orders owners of certain **Piper PA-31 series aeroplanes** (including the PA-31, PA-31-325, PA-31-300, and PA-31-350 models with specific serial numbers) to modify the **cabin door latch** (the locking mechanism that keeps the passenger door closed during flight).\n\n**Who it affects:** Owners and operators of these specific Piper twin-engine aircraft, manufactured with serial numbers ranging from 31-2 up to 31-7512029 for most models, and 31-5001 to 31-7552052 for the PA-31-350 variant. There's an exception: aircraft that have already had three specific modification kits installed (referenced in Piper Service Letter 739) don't need to do this.\n\n**What you must do:** Follow the instructions in **Piper Service Letter 803A** to modify the door latch. This must be done within **100 hours of flight time** after 31 May 1978 — unless the fix was already completed before that date.\n\n**Why it matters:** Door latch failures can cause doors to open unexpectedly in flight, creating dangerous cabin pressure loss, noise, and distraction. This AD prevents that safety risk by ensuring a stronger, more reliable latch mechanism is installed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-65-cabin-door-latch-modification","history":"/api/acts/ad-pa-31-65-cabin-door-latch-modification/history","analysis":"/api/acts/ad-pa-31-65-cabin-door-latch-modification/analysis","conflicts":"/api/acts/ad-pa-31-65-cabin-door-latch-modification/conflicts","importantCases":"/api/acts/ad-pa-31-65-cabin-door-latch-modification/important-cases","documents":"/api/acts/ad-pa-31-65-cabin-door-latch-modification/documents"}}