{"id":"F2006B09081","name":"AD/DHC-3/31 - Control Column Cracking","slug":"ad-dhc-3-31-control-column-cracking","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115634,"registerId":"commonwealth-F2006B09081-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-3/31 - Control Column Cracking","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)  DHC-3 (Otter) Series Aeroplanes\n\n \n\nAD/DHC-3/31 Control Column Cracking 13/87\n\nApplicability: All models.\n\n \n\nRequirement: Action in accordance with the Havilland Canada SB 3/39 Rev B.\n\n \n\nCompliance: In accordance with the criteria listed in the Requirement Document but prior to the issue of an initial Certificate of Airworthiness.\n\n \n\nNote 1. Canadian AD CF-82-34 refers.\n\n \n\nNote 2. An inspection is required whenever a parked aircraft is subjected to the adverse wind conditions descried in the Requirement Document.\n\n \n\nBackground:  There have been reported cracks in the lower welded assembly at the base of the control column. The cracking is attributed to ground gust loading of the elevator surfaces.\n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies to all DHC-3 models and requires compliance with a specified service bulletin and event-driven inspections. There is no text in this instrument that expands or narrows the stated applicability or obligations beyond those elements (see \"Applicability: All models\", \"Requirement: Action in accordance with the Havilland Canada SB 3/39 Rev B\", \"Compliance: ... prior to the issue of an initial Certificate of Airworthiness\", \"Note 2\"). Therefore the scope appears consistent with the directive's stated intent to address control-column cracking and has not been altered within the text provided."},"complexity_factors":["References an external technical document (Havilland Canada SB 3/39 Rev B) for the substantive inspection and repair steps, requiring operators to obtain and interpret that material (\"Requirement: Action in accordance with the Havilland Canada SB 3/39 Rev B\").","Event-triggered inspections (inspection required after specified adverse wind exposure) create operational uncertainty and monitoring obligations (\"Note 2\").","Mandatory timing constraint before initial Certificate of Airworthiness creates an administrative/operational bottleneck for newly certificated aircraft (\"Compliance: ... prior to the issue of an initial Certificate of Airworthiness\").","The AD itself contains no technical inspection criteria or repair instructions, increasing reliance on maintenance providers and the SB for implementation (implicit from the text of the Requirement).","Cross-reference to another jurisdiction's AD (Canadian AD CF-82-34) requires checking related documents for context (\"Note 1\")."],"plain_english_summary":"If you own or operate a DHC‑3 (Otter), this directive requires you to follow Havilland Canada SB 3/39 Rev B: carry out the prescribed inspections and corrective work before initial Certificate of Airworthiness and whenever specified adverse wind exposure occurs. It responds to reported cracks at the base of the control column from ground gust loading. Owners/operators bear compliance costs and may need to change parking or maintenance practices."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive focused specifically on control column cracking in one aircraft type. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Very short document (under 200 words)","Only 1 substantive requirement referencing an external technical document (Havilland Canada SB 3/39 Rev B)","No defined terms section","Simple conditional trigger: compliance required before Certificate of Airworthiness issuance, plus repeat inspections after adverse wind exposure","Minimal cross-referencing (one Canadian AD mentioned in a note, not binding)","Single applicability criterion (all models)"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for a specific type of aircraft.\n\n**What it does:** It requires owners and operators of de Havilland Canada DHC-3 \"Otter\" aeroplanes to inspect the control column (the pilot's steering stick) for cracks in a specific welded joint at its base. The cracking is caused by wind blowing against the tail surfaces while the plane is parked on the ground.\n\n**Who must comply:** Anyone who owns or operates any model of DHC-3 Otter aircraft.\n\n**When it must be done:** Before the aircraft can get its first Certificate of Airworthiness (the official document saying it's safe to fly). Additionally, the inspection must be repeated whenever the aircraft is parked in high winds as described in the manufacturer's service bulletin.\n\n**Why it matters:** Cracks in the control column could lead to loss of control of the aircraft. This AD prevents accidents by catching fatigue damage early, particularly in aircraft exposed to windy conditions on the ground."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-3-31-control-column-cracking","history":"/api/acts/ad-dhc-3-31-control-column-cracking/history","analysis":"/api/acts/ad-dhc-3-31-control-column-cracking/analysis","conflicts":"/api/acts/ad-dhc-3-31-control-column-cracking/conflicts","importantCases":"/api/acts/ad-dhc-3-31-control-column-cracking/important-cases","documents":"/api/acts/ad-dhc-3-31-control-column-cracking/documents"}}