{"id":"F2006B08948","name":"AD/DH114/37 Amdt 1 - Main Undercarriage Damper Ram - Inspection","slug":"ad-dh114-37-amdt-1-main-undercarriage-damper-ram-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52582,"registerId":"commonwealth-F2006B08948-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH114/37 Amdt 1 - Main Undercarriage Damper Ram - Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nDH114 (Heron) Series Aeroplanes\n\nAD/DH114/37\n\nAmdt 1\n\n  \nMain Undercarriage Damper Ram \\- Inspection NK\n\nApplicability: All Series 2 aircraft.\n\nRequirement: 1\\. Check that the lower attachment bolt of the damper ram can be turned easily in situ using a spanner. If the bolt cannot be easily turned the ram shall be replaced with a serviceable unit before further flight.\n\nNote: Experience has shown that an unserviceable ram becomes internally pressurised and exerts sufficient end load to make bolt turning extremely difficult or impossible.\n\n2. Replace existing damper rams P/N AC 11164 with units of same P/N modified in accordance with Dunlop SB No. 32-824 or new damper rams P/N A/C 65528.\n\nCompliance: For Para. 1 \\- At each daily or overnight inspection until modified or replaced in accordance with Hawker TNS No. U.15, Issue 2.\n\nFor Para. 2 \\- Before 1 July 1974.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment adds a specific parts/repair requirement to replace existing damper rams P/N AC 11164 by modifying them per Dunlop SB No. 32-824 or installing new rams P/N A/C 65528 (Requirement 2) and sets a compliance deadline for that work (Compliance for Para. 2). It also prescribes that the manual bolt-turning check be carried out at each daily or overnight inspection until the unit is modified or replaced in accordance with Hawker TNS No. U.15, Issue 2 (Requirement 1; Compliance for Para. 1). These additions change the directive from only requiring inspection to requiring a specified hardware modification or replacement within a stated timeframe."},"complexity_factors":["Simple mechanical requirement: single manual check (bolt turning) is straightforward to perform (Requirement 1).","Mandated parts/repair options reference external service documents (Dunlop SB No. 32-824; Hawker TNS No. U.15, Issue 2), creating dependency on other technical materials (Requirement 2; Compliance for Para. 1).","Recurring inspection until modification or replacement introduces ongoing operational burden (Compliance for Para. 1).","A fixed compliance deadline for parts replacement imposes scheduling and supply considerations (Compliance for Para. 2).","Subjectivity of the “can be turned easily” test can create variability in enforcement and replacement decisions (Requirement 1; Note)."],"plain_english_summary":"This AD applies to DH114 Series 2 (Heron) aeroplanes: operators must at each daily/overnight inspection check that the main undercarriage damper ram’s lower attachment bolt “turns easily” with a spanner and replace any ram that fails before further flight. It also requires that units P/N AC 11164 be modified per Dunlop SB No. 32‑824 or replaced with P/N A/C 65528 by the directive’s compliance date. It affects owners, operators and maintenance providers and aims to prevent rams becoming internally pressurised and seizing the bolt."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a specific technical airworthiness directive addressing a known safety defect in a particular aircraft type. It has not expanded beyond its original purpose of ensuring landing gear safety through inspection and replacement requirements."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 substantive requirements with clear compliance deadlines","Single defined term (P/N = Part Number, implied by context)","No cross-references to other legislation or complex conditional logic","Straightforward applicability (all Series 2 aircraft)","Simple binary test (bolt turns easily vs. doesn't turn)"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **DH114 Heron Series 2 aircraft**.\n\n**What it does:**\nIt requires owners and operators to inspect and replace faulty main undercarriage damper rams (shock-absorbing components in the landing gear).\n\n**The safety problem:**\nDamper rams can become internally pressurised and seize up. If the lower attachment bolt cannot be turned easily with a spanner, the ram is faulty and must be replaced before the aircraft flies again.\n\n**What must be done:**\n- **Immediate action:** At every daily or overnight inspection, check if the damper ram's lower bolt turns freely. If stuck, replace the ram immediately.\n- **Permanent fix:** Replace old damper rams (part number AC 11164) with modified units or new ones (part number A/C 65528) before 1 July 1974.\n\n**Who it affects:**\nOperators of DH114 Heron Series 2 aeroplanes.\n\n**Why it matters:**\nA seized damper ram could compromise the landing gear's ability to absorb shocks during landing, potentially causing structural damage or loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh114-37-amdt-1-main-undercarriage-damper-ram-inspection","history":"/api/acts/ad-dh114-37-amdt-1-main-undercarriage-damper-ram-inspection/history","analysis":"/api/acts/ad-dh114-37-amdt-1-main-undercarriage-damper-ram-inspection/analysis","conflicts":"/api/acts/ad-dh114-37-amdt-1-main-undercarriage-damper-ram-inspection/conflicts","importantCases":"/api/acts/ad-dh114-37-amdt-1-main-undercarriage-damper-ram-inspection/important-cases","documents":"/api/acts/ad-dh114-37-amdt-1-main-undercarriage-damper-ram-inspection/documents"}}