{"id":"F2006B02381","name":"AD/AMD 50/14 Amdt 1 - Horizontal Stabiliser Hinge","slug":"ad-amd-50-14-amdt-1-horizontal-stabiliser-hinge","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41611,"registerId":"commonwealth-F2006B02381-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AMD 50/14 Amdt 1 - Horizontal Stabiliser Hinge","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)  \nAMD Falcon 50 and 900 Series Aeroplanes\n\nAD/AMD 50/14\n\nAmdt 1\n\n  \nHorizontal Stabiliser Hinge 9/99\n\nApplicability: Mystere Falcon 50 aircraft with serial numbers 242 through 262, Mystere Falcon 900 aircraft with serial numbers 139 through 169, and Falcon 900 EX aircraft with serial numbers 1 through 21.\n\nRequirement: 1. Incorporate the following temporary changes and revisions, as applicable: For the MF 50:\n\nAircraft Flight Manual, TC 46 (TC 12 for S/N 251, 253 on).\n\nMaintenance Manual Chapter 5-40, Revision 10.\n\nFor the MF 900:\n\nAircraft Flight Manual, TC 69.\n\nMaintenance Manual Chapter 5-40, Revision 9.\n\nFor the F 900 EX:\n\nAircraft Flight Manual, TC 14.\n\nMaintenance Manual Chapter 5-40, Revision 2.\n\n    2. Perform the check specified in Chapter 5 of the Maintenance Manual at the revision status referenced in Requirement 1 of this Directive, as applicable.\n\n    3. Action in accordance with Dassault Aviation Service Bulletin F 50-274, F 900- 203, or F 900 EX-37, as applicable.\n\nNote: DGAC AD 1997-370-020 (B) R2 refers.\n\nCompliance: 1. Unless already accomplished, before 23 May 1998.\n\n    2. Before 27 February 2004 or supplementary 3750 flight cycles, whichever occurs first.\n\n    3. Before 6 years and 2 Months or 3750 flight cycles since new, whichever occurs first.\n\nThe compliance remains unchanged for Requirement 1 of this Directive. This Amendment becomes effective on 9 September 1999.\n\nBackground: A check performed on a test aircraft revealed deformation of the horizontal stabiliser attachment and hinge outer rings which may create excessive play in the hinge.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nAmendment 1 is issued in response to a new DGAC AD which deletes the mandatory inspection to be performed after a stall as required in Maintenance Manual Chapter 5.50\n\nThe original issue of this Airworthiness Directive became effective on 23 April 1998.","sortOrder":0}],"analysis":{"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This Amendment narrowed the directive's inspection scope by deleting the previously mandatory post‑stall inspection required in Maintenance Manual Chapter 5.50. Mechanically, the AD preserves the original requirements to update manuals, perform the Chapter 5 check, and follow Dassault service bulletin corrective actions, but it removes one mandatory inspection element that had been part of the original AD's maintenance prescriptions. That change reduces the number of compulsory inspections imposed on operators and shifts the balance of regulatory burden (fewer mandatory checks) while leaving the other requirements and their compliance deadlines intact."},"complexity_factors":["Short standalone directive (single-issue AD) with three clear numbered requirements","References to model-specific manuals and explicit revision numbers (Maintenance Manual Chapter 5-40 at multiple revision levels)","Multiple model variants and serial-number ranges listed (three type/serial groups)","Three distinct compliance timelines with 'whichever occurs first' conditions (calendar date vs flight cycles vs age since new)","Cross-references to external documents: Dassault service bulletins and DGAC AD (requires consulting those documents for technical detail)","Amendment modifies prior requirement set (deletes a previous mandatory post-stall inspection), requiring checking against earlier AD text for full history"],"plain_english_summary":"**What this directive does (mechanically):**\n\n- Applies to specific Dassault Mystere Falcon business jets: Falcon 50 (S/N 242–262), Falcon 900 (S/N 139–169) and Falcon 900EX (S/N 1–21).\n- Requires operators to make specified temporary changes and revisions to the Aircraft Flight Manual and to a particular chapter of the Maintenance Manual (Maintenance Manual Chapter 5-40) at the revision levels named in Requirement 1.\n- Requires operators/maintenance organisations to carry out the inspection/check described in Chapter 5 of the Maintenance Manual at the revision level referenced in Requirement 1 (Requirement 2).\n- Requires corrective action in accordance with the applicable Dassault Aviation Service Bulletin for the model (Requirement 3).\n- Provides specific deadlines for each requirement (see “Compliance” below).\n\n**Who has to act and who pays:**\n\n- Aircraft owners/operators must update manuals, perform the inspection(s), and carry out any required corrective work. They therefore bear the cost of labour, parts, and aircraft downtime.\n- Maintenance organisations (approved maintenance providers) will carry out the manual revisions, inspections and repairs and will decide scheduling and technical work consistent with the service bulletin.\n- Dassault Aviation provides the technical instructions (service bulletins) that describe the required corrective actions.\n- The Civil Aviation Safety Authority (CASA) issues the directive and sets the compliance dates; the French DGAC AD that is cross‑referenced influenced this Australian amendment.\n\n**Deadlines and timing (how the directive works):**\n\n- Requirement 1 (incorporate manual revisions): unless already done, must be completed before 23 May 1998. (The directive notes this compliance timing is unchanged by the amendment.)\n- Requirement 2 (perform the check in Chapter 5): must be done before 27 February 2004 or before the aircraft accumulates 3,750 supplementary flight cycles, whichever comes first.\n- Requirement 3 (take action per the Dassault service bulletin): must be done before an aircraft is 6 years and 2 months old or before 3,750 flight cycles since new, whichever comes first.\n\n**Why the rule was made (official rationale and what that implies):**\n\n- Background testing found deformation of the horizontal stabiliser attachment and hinge outer rings that might create excessive play (slop) in the hinge. Excessive play in the stabiliser hinge can affect aerodynamic control surfaces and is therefore treated as an airworthiness (safety) issue.\n- The Amendment (Amdt 1) responds to a new French DGAC airworthiness directive that removed a previously mandatory inspection after a stall (Maintenance Manual Chapter 5.50). Practically, this amendment narrows the set of mandatory checks by deleting that specific post‑stall mandatory inspection and keeps or re‑states the other inspection and corrective-action requirements.\n\n**Costs, incentives and trade-offs (practical effects):**\n\n- Direct compliance costs fall on the aircraft operators: updating manuals, scheduling inspections, possible replacement or repair of hinge components, and associated aircraft downtime.\n- Maintenance organisations and parts suppliers will perform the work and therefore may gain business (concentrated benefit to providers of maintenance and replacement parts). The operators bear most of the cost (concentrated cost) and the wider public bears none directly.\n- Deleting the mandatory post‑stall inspection reduces one inspection burden (lower cost and less downtime for operators), but it also reduces the number of compulsory checks targeted at the hinge condition; that is a deliberate change in regulatory scope and represents a trade‑off between inspection burden and frequency of an outcome check.\n- Implementation risk and compliance burden: operators must track multiple deadlines that are tied to calendar age and flight cycles (whichever is earlier), ensure manuals are updated to the specified revision status, and ensure maintenance actions are performed exactly as the referenced Dassault service bulletins require. Mis-tracking could leave a required action undone.\n- Bureaucratic and technical discretion: CASA enforces the AD; the DGAC action and Dassault service bulletins define the technical method. The directive cross‑references foreign authority (DGAC) and manufacturer documentation, so technical detail and continued conformity depend on those external documents.\n\n**Behavioral change required:**\n\n- Operators must adopt the updated flight and maintenance manual entries and follow the specified inspection regime and corrective actions rather than only their previous maintenance practice.\n- Maintenance organisations must perform the specific check and any required repairs per the service bulletin and record compliance in aircraft maintenance records.\n\n**Cross-references and source notes:**\n\n- The AD references Dassault Aviation Service Bulletins F 50-274, F 900-203, and F 900 EX-37 (model specific) for the corrective actions, and it notes DGAC AD 1997-370-020 (B) R2.\n\n(References in text: Requirement 1, Requirement 2, Requirement 3, Compliance, Background, and the Amendment note that deletes the mandatory stall inspection.)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a narrow, technical airworthiness directive focused on a specific mechanical defect in specific aircraft. The amendment slightly narrows the scope by removing a stall-related inspection requirement, but does not expand beyond the original safety purpose."},"complexity_factors":["Multiple applicability criteria requiring serial number cross-checking (three aircraft types with specific serial number ranges)","Three separate compliance deadlines with 'whichever occurs first' conditional logic","Requirement to incorporate multiple document revisions across different manual types (Aircraft Flight Manual vs Maintenance Manual) with different revision numbers for each aircraft variant","Cross-reference to French regulatory document (DGAC AD 1997-370-020(B)R2) without full reproduction","Nested applicability: Requirement 1 compliance 'remains unchanged' while Amendment 1 modifies other requirements"],"plain_english_summary":"This safety order applies to specific Dassault Falcon 50, 900 and 900EX business jets and addresses deformation of the horizontal stabiliser hinge rings that can create dangerous play and affect control. It requires operators to adopt temporary manual revisions, follow Dassault service bulletins, and carry out the mandated hinge inspections within the stated time/cycle limits. The amendment aligns Australian rules with the French DGAC change removing post‑stall mandatory inspections while retaining other safeguards."}},"importantCases":[],"_links":{"self":"/api/acts/ad-amd-50-14-amdt-1-horizontal-stabiliser-hinge","history":"/api/acts/ad-amd-50-14-amdt-1-horizontal-stabiliser-hinge/history","analysis":"/api/acts/ad-amd-50-14-amdt-1-horizontal-stabiliser-hinge/analysis","conflicts":"/api/acts/ad-amd-50-14-amdt-1-horizontal-stabiliser-hinge/conflicts","importantCases":"/api/acts/ad-amd-50-14-amdt-1-horizontal-stabiliser-hinge/important-cases","documents":"/api/acts/ad-amd-50-14-amdt-1-horizontal-stabiliser-hinge/documents"}}