{"id":"F2009L01844","name":"AD/B727/218 - Upper and Lower Fuselage Skin Lap Joints","slug":"ad-b727-218-upper-and-lower-fuselage-skin-lap-joints","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":78852,"registerId":"commonwealth-F2009L01844-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 727 Series Aeroplanes","sectionType":"division","heading":"Boeing 727 Series Aeroplanes","content":"### Boeing 727 Series Aeroplanes\n\n| AD/B727/218 | Upper and Lower Fuselage Skin Lap Joints | 6/2009 |\n| ----------- | ---------------------------------------- | ------ |\n\n| Applicability: | Model 727-100 and 727-200 series aircraft, as identified in Boeing Alert Service Bulletin 727-53A0223, dated 28 March 2002, or later FAA approved revision.                                                                                                                                                                                                                                                                                                    |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2009-06-10Amdt 39-15846.                                                                                                                                                                                                                                                                                                                                                                        |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of4 June 2009.                                                                                                                                                                                                                                                                                                                                                                         |\n|                | This Airworthiness Directive becomes effective on 4 June 2009.                                                                                                                                                                                                                                                                                                                                                                                                 |\n| Background:    | A report of decompression in a Model 737 aircraft at flight level 290 prompted the issue of FAA AD 2009-06-10. The actions required by this Directive are intended to detect and correct scratches and excessive reduction of material thickness from excessive blend-out or corrosion, which could lead to premature cracking in the upper and lower fuselage skin lap joints. Such cracking could adversely affect the structural integrity of the aircraft. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n17 April 2009","sortOrder":0},{"sectionNumber":"AD/B727/218","sectionType":"part","heading":"AD/B727/218","content":"## AD/B727/218","sortOrder":1},{"sectionNumber":"Upper and Lower Fuselage Skin Lap Joints","sectionType":"part","heading":"Upper and Lower Fuselage Skin Lap Joints","content":"## Upper and Lower Fuselage Skin Lap Joints","sortOrder":2},{"sectionNumber":"6/2009","sectionType":"part","heading":"6/2009","content":"## 6/2009","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope. It addresses a specific structural integrity issue (fuselage lap joint cracking) on a specific aircraft type (Boeing 727 series) following a safety incident on a related aircraft type. There is no evidence of scope creep — the directive does not expand beyond its original safety purpose of preventing decompression through targeted inspection and repair."},"complexity_factors":["Short, single-purpose directive (approximately 200 words of substantive content)","Only 1 defined applicability criterion (specific aircraft models via service bulletin reference)","Minimal conditional logic — compliance is mandatory without exceptions or alternative methods stated in the text itself","Heavy reliance on external documents (FAA AD 2009-06-10 and Boeing Service Bulletin 727-53A0223) for actual technical requirements — the directive itself is essentially a 'pointer' to these documents","No nested exceptions or layered definitions within the directive text","Simple tabular format with clear applicability, requirement, compliance, and background sections"],"plain_english_summary":"This FAA Airworthiness Directive mandates owners/operators of Boeing 727-100/-200 series inspect and repair upper and lower fuselage lap joints for scratches, excessive material removal, or corrosion per Boeing Alert Service Bulletin 727-53A0223 (and AD 2009-06-10). Prompt action prevents premature cracking that could compromise structural integrity and risk decompression; compliance is mandatory by the AD’s specified timelines."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This instrument adopts the FAA AD's technical requirements for inspecting and repairing upper and lower fuselage skin lap joints and sets an effective date of 4 June 2009. It does not expand the population or substantive obligations beyond the FAA AD and the Boeing Alert Service Bulletin referenced."},"complexity_factors":["Cross-reference dependency: adopts technical requirements from FAA AD 2009-06-10A and Boeing Alert Service Bulletin 727-53A0223 (requires tracking external documents).","Targeted structural inspections: requires non-routine assessment of lap joint scratches, blend‑out thickness loss and corrosion—inspection judgement and measurement precision needed.","Compliance timing and recordkeeping: revised effective date and mandatory compliance schedule create operational planning and maintenance-record burdens.","Potential operational impact: repairs may require disassembly, parts replacement or grounding, producing direct costs and aircraft downtime.","Limited applicability: applies only to 727-100/200 airframes identified in the specified service bulletin, so applicability determination is necessary before action."],"plain_english_summary":"This Airworthiness Directive requires operators of Boeing 727‑100 and 727‑200 aircraft identified in Boeing Alert Service Bulletin 727‑53A0223 to carry out inspections and corrective action on upper and lower fuselage skin lap joints, following the technical requirements of FAA AD 2009‑06‑10A. It becomes effective 4 June 2009. The stated purpose is to detect and repair scratches, excessive material loss from blend‑out, or corrosion that could lead to premature cracking and reduce structural integrity. Operators pay inspection and repair costs; CASA enforces the FAA technical standard."},"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-b727-218-upper-and-lower-fuselage-skin-lap-joints","history":"/api/acts/ad-b727-218-upper-and-lower-fuselage-skin-lap-joints/history","analysis":"/api/acts/ad-b727-218-upper-and-lower-fuselage-skin-lap-joints/analysis","conflicts":"/api/acts/ad-b727-218-upper-and-lower-fuselage-skin-lap-joints/conflicts","importantCases":"/api/acts/ad-b727-218-upper-and-lower-fuselage-skin-lap-joints/important-cases","documents":"/api/acts/ad-b727-218-upper-and-lower-fuselage-skin-lap-joints/documents"}}