{"id":"F2006B02697","name":"AD/B727/173 - Horizontal Stabiliser Hinge Pin","slug":"ad-b727-173-horizontal-stabiliser-hinge-pin","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42013,"registerId":"commonwealth-F2006B02697-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nBoeing 727 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/B727/173 Horizontal Stabiliser Hinge ","sectionType":"part","heading":"AD/B727/173 Horizontal Stabiliser Hinge Pin 13/2001","content":"# AD/B727/173 Horizontal Stabiliser Hinge Pin 13/2001\n\nApplicability: All Model 727 series aircraft.\n\nRequirement: Inspect in accordance with the technical requirements of FAA AD 2001-22-12 Amdt 39-12491.\n\nNote: Boeing Alert Service Bulletin 727-55A0090 Revision 1 refers.\n\nCompliance: As specified in the Requirement document with a revised effective date of 27 December 2001.\n\nThis Airworthiness Directive becomes effective on 27 December 2001.\n\nBackground: The FAA received reports of cracks and corrosion in the outer hinge pins that attach the horizontal stabiliser to the vertical fin on several Model 727 series aircraft.\n\nCorrosion has also been found on inner fail-safe hinge pins. Such corrosion or cracking could lead to structural degradation of the stabiliser hinge joint and consequent loss of the horizontal stabiliser, which would result in loss of controllability of the aircraft.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 16 November 2001\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 5 December 2001.","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD maintains the original safety scope: inspecting horizontal stabiliser hinge pins on all Model 727s (Applicability; Requirement). The instrument does not broaden affected aircraft or add new fault types; it primarily enforces FAA AD 2001-22-12 and sets a revised effective date of 27 December 2001 (Compliance)."},"complexity_factors":["Cross‑references to external mandatory technical document: FAA AD 2001-22-12 (Requirement) — operators must follow another regulator’s detailed procedures.","Reference to manufacturer service information (Boeing Alert Service Bulletin 727-55A0090 Rev 1) creates layered technical sources to reconcile (Note).","Applicability covers all Model 727 series aircraft, producing uniform obligation across the operator population (Applicability).","Compliance timing fixed by directive (Compliance) but relies on the external documents for the specific inspection intervals and methods, increasing operational dependency on those texts.","Safety‑critical inspection and potential corrective work impose direct costs and maintenance scheduling burdens on operators (Requirement; Background).","Limited statutory discretion visible: CASA delegate issues the AD under subregulation 39.1(1), but the AD delegates technical detail to the FAA AD and Boeing service bulletin (preamble and Requirement/Note)."],"plain_english_summary":"This Airworthiness Directive requires operators of all Boeing 727 series aircraft to inspect the horizontal stabiliser hinge pins for corrosion or cracking, following the technical requirements of FAA AD 2001‑22‑12 (see Requirement and Applicability). The aircraft operator must arrange and pay for inspections and any corrective work; the directive sets the compliance timing with a revised effective date of 27 December 2001 and cites the safety risk of hinge‑pin failure causing loss of stabiliser (Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with a narrow, specific safety purpose: addressing a known structural defect in a particular aircraft type. The scope remains tightly focused on the original safety concern without expansion into broader regulatory matters."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined term implicitly used ('Model 727 series aircraft')","Single, clear requirement: inspect per external FAA document","No nested conditions or exceptions","No cross-references to other Australian legislation","Incorporates external technical standard by reference (FAA AD 2001-22-12) rather than reproducing it"],"plain_english_summary":"The Civil Aviation Safety Authority is ordering all owners and operators of Boeing 727 series aircraft to inspect the hinge pins that attach the horizontal stabiliser to the tail, adopting FAA Airworthiness Directive 2001-22-12 and Boeing’s service bulletin.  \n\nThis follows FAA reports of cracks and corrosion that could allow stabiliser separation and loss of control; inspections must be completed to the FAA timeline, with the Australian order effective 27 December 2001."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-173-horizontal-stabiliser-hinge-pin","history":"/api/acts/ad-b727-173-horizontal-stabiliser-hinge-pin/history","analysis":"/api/acts/ad-b727-173-horizontal-stabiliser-hinge-pin/analysis","conflicts":"/api/acts/ad-b727-173-horizontal-stabiliser-hinge-pin/conflicts","importantCases":"/api/acts/ad-b727-173-horizontal-stabiliser-hinge-pin/important-cases","documents":"/api/acts/ad-b727-173-horizontal-stabiliser-hinge-pin/documents"}}