{"id":"F2006B03518","name":"AD/BAe 146/70 - Skin Inspection at Frame 29 between Stringers 12 and 13","slug":"ad-bae-146-70-skin-inspection-at-frame-29-between-stringers-12-and-13","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43085,"registerId":"commonwealth-F2006B03518-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/70 - Skin Inspection at Frame 29 between Stringers 12 and 13","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  British Aerospace BAe 146 Series Aeroplanes\n\n \n\nAD/BAe 146/70  Skin Inspection at Frame 29 between Stringers 12 and 13\n\n\n8/98\n\n \n\nApplicability: All BAe 146 Series 100 and 200 aircraft, and Series 300 aircraft with constructors numbers listed in effectivity of SB 53-144.\n\n \n\nRequirement: Inspect in accordance with British Aerospace Mandatory Service Bulletin 53-144, classified mandatory by UK CAA.\n\n \n\nCompliance: As specified in the Requirement document.\n\n \n\nThis airworthiness directive becomes effective on 16 July 1998.\n\n \n\nBackground: Fatigue cracking of the skin in the vicinity of frame 29 between stingers 12 and 13 has been found on two aircraft during routine inspection.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific structural integrity issue on a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection for fatigue cracking at a particular fuselage location."},"complexity_factors":["Very short document (approximately 150 words)","Only 4 substantive sections: Applicability, Requirement, Compliance, and Background","Single technical reference to external document (Service Bulletin 53-144)","No defined terms section","No conditional logic or nested exceptions","Straightforward command structure: inspect this specific location on these specific aircraft"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific British Aerospace BAe 146 aircraft.\n\n**What it requires:** Owners and operators of affected BAe 146 planes must inspect a specific part of the aircraft's fuselage (the outer skin near \"frame 29 between stringers 12 and 13\") for cracks caused by metal fatigue. The inspection must follow the exact procedure laid out in British Aerospace Service Bulletin 53-144.\n\n**Who it affects:** \n- All BAe 146 Series 100 and 200 aircraft\n- BAe 146 Series 300 aircraft with specific construction numbers listed in the service bulletin\n\n**Why it matters:** Fatigue cracks were discovered in this exact location on two aircraft during routine checks. If left unchecked, these cracks could worsen and potentially lead to structural failure — a serious safety risk. This directive ensures all affected planes get checked before a dangerous situation develops.\n\n**When it took effect:** 16 July 1998.\n\n**Key point:** This is a reactive safety measure — it doesn't mean all these planes are unsafe, but it mandates a specific inspection to catch a known potential problem early."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive does not expand or narrow the class of activities regulated beyond imposing a specific inspection requirement for the stated group of aircraft. It prescribes compliance with a named service bulletin for identified airframes and does not indicate a broader change in regulatory scope or certification requirements (Applicability; Requirement)."},"complexity_factors":["Dependence on an external technical document (British Aerospace Mandatory Service Bulletin 53-144) for inspection method and effectivity (Requirement).","Applicability includes all Series 100 and 200 but restricts Series 300 to constructor numbers listed in the Service Bulletin, creating a conditional scope (Applicability).","No repair criteria, intervals or allowed alternatives are specified in the AD itself; operators must consult the Service Bulletin and potentially other regulatory material (Requirement; Compliance).","Implementation requires maintenance resources and scheduling that vary by operator, introducing operational complexity though not legislative complexity (Compliance).","Interplay between CASA’s AD and the UK CAA classification of the SB means compliance relies on cross-jurisdictional technical determinations (Requirement)."],"plain_english_summary":"This AD, effective 16 July 1998, mandates the inspection in BAe Mandatory Service Bulletin 53-144 (as classified by the UK CAA) of the skin at frame 29 between stringers 12 and 13 on specified BAe 146 Series 100/200 and certain Series 300 aircraft after fatigue cracking was found. Operators must carry out and pay for the inspections and any repairs, increasing maintenance workload and potential aircraft downtime."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-70-skin-inspection-at-frame-29-between-stringers-12-and-13","history":"/api/acts/ad-bae-146-70-skin-inspection-at-frame-29-between-stringers-12-and-13/history","analysis":"/api/acts/ad-bae-146-70-skin-inspection-at-frame-29-between-stringers-12-and-13/analysis","conflicts":"/api/acts/ad-bae-146-70-skin-inspection-at-frame-29-between-stringers-12-and-13/conflicts","importantCases":"/api/acts/ad-bae-146-70-skin-inspection-at-frame-29-between-stringers-12-and-13/important-cases","documents":"/api/acts/ad-bae-146-70-skin-inspection-at-frame-29-between-stringers-12-and-13/documents"}}