{"id":"F2009L00898","name":"AD/A320/231 - Flap Track No.1 Pendulum Assembly","slug":"ad-a320-231-flap-track-no-1-pendulum-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":78225,"registerId":"commonwealth-F2009L00898-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Airbus Industrie A319, A320 and A321 Ser","sectionType":"division","heading":"Airbus Industrie A319, A320 and A321 Series Aeroplanes","content":"### Airbus Industrie A319, A320 and A321 Series Aeroplanes\n\n| AD/A320/231 | Flap Track No.1 Pendulum Assembly | 4/2009 |\n| ----------- | --------------------------------- | ------ |\n\n| Applicability: | Model A318-111, -112, -121 and -122 aircraft, all serial numbers.Model A319-111, -112, -113, -114, -115, -131, -132 and -133 aircraft, all serial numbers.Model A320-111, -211, -212, -214, -215, -216, -231, -232 and -233 aircraft, all serial numbers.Model A321-111, -112, -131, -211, -212, -213, -231 and 232 aircraft, all serial numbers.                                                                                                                                                                                          |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Action in accordance with the requirements of EASA AD 2009-0025, Corrected11 February 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of9 April 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 9 April 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| Background:    | During a routine inspection on an A321 aircraft, the operator discovered that a bearing of the flap track No. 1 pendulum assembly had migrated out of position. An investigation has revealed that the pendulum bearing migration was probably due to the methods used during an in-service replacement of the bearing during maintenance. This Directive requires a one-time inspection of the affected flap track No.1 pendulum assembly, and if bearing migration is evident, replacement of the affected flap track pendulum assembly. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n24 February 2009","sortOrder":0},{"sectionNumber":"AD/A320/231","sectionType":"part","heading":"AD/A320/231","content":"## AD/A320/231","sortOrder":1},{"sectionNumber":"Flap Track No.1 Pendulum Assembly","sectionType":"part","heading":"Flap Track No.1 Pendulum Assembly","content":"## Flap Track No.1 Pendulum Assembly","sortOrder":2},{"sectionNumber":"4/2009","sectionType":"part","heading":"4/2009","content":"## 4/2009","sortOrder":3}],"analysis":{"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. The scope remains tightly focused on the identified mechanical defect in the flap track pendulum assembly. There is no evidence of scope creep or expansion beyond the original safety intent."},"complexity_factors":["Very short document (approximately 250 words)","Only 4 defined elements: applicability (aircraft models), requirement (reference to external EASA AD), compliance date, and background","No nested conditional logic — simple binary outcome (inspect, then replace if problem found)","Single cross-reference to external document (EASA AD 2009-0025) rather than internal legislative cross-references","No exceptions, exemptions, or penalty clauses","Straightforward command structure: identify aircraft → inspect → replace if necessary"],"plain_english_summary":"This CASA Airworthiness Directive mandates a one‑time inspection of the flap track No.1 pendulum assembly on certain Airbus A318/A319/A320/A321 aircraft to check for migrated bearings; if a bearing is out of position the entire assembly must be replaced. It affects operators of those models, follows an EASA action with compliance dates from 9 April 2009, and addresses a safety risk to flap function during takeoff and landing."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument confines action to a one-time inspection and replacement of flap track No.1 pendulum assemblies where bearing migration is found, consistent with the stated purpose of addressing in-service bearing migration caused during maintenance. It delegates procedural detail to EASA AD 2009-0025 and does not expand scope to other components or recurring inspections (Requirement; Background)."},"complexity_factors":["Cross-reference to an external document (EASA AD 2009-0025) for detailed procedures creates a dependency on another instrument (Requirement).","Applicability covers multiple Airbus A318/A319/A320/A321 models and all serial numbers, widening the population affected but not the procedural variety (Applicability).","The substantive technical determination—whether bearing migration is \"evident\"—requires specialist inspection judgement and possible parts replacement (Background).","The directive is a one-time action with a fixed effective date (9 April 2009), which lowers ongoing compliance complexity but concentrates near-term workload (Compliance).","Enforcement is under CASA via its delegate, leaving limited regulatory discretion beyond requiring compliance with the referenced EASA AD (signed delegate statement)."],"plain_english_summary":"This Airworthiness Directive requires operators of specified Airbus A318/A319/A320/A321 series aeroplanes to perform a one-time inspection of the flap track No.1 pendulum assembly and, if a bearing has migrated, to replace the pendulum assembly in accordance with EASA AD 2009-0025 (Requirement). Operators pay for the inspection and any replacement, must comply by the effective date (9 April 2009), and will change maintenance practice to inspect and rectify bearing migration after in-service bearing work (Background)."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-231-flap-track-no-1-pendulum-assembly","history":"/api/acts/ad-a320-231-flap-track-no-1-pendulum-assembly/history","analysis":"/api/acts/ad-a320-231-flap-track-no-1-pendulum-assembly/analysis","conflicts":"/api/acts/ad-a320-231-flap-track-no-1-pendulum-assembly/conflicts","importantCases":"/api/acts/ad-a320-231-flap-track-no-1-pendulum-assembly/important-cases","documents":"/api/acts/ad-a320-231-flap-track-no-1-pendulum-assembly/documents"}}