{"id":"F2007L01348","name":"AD/BAe 146/128 - Aft Fuselage Skin under APU Heat Shield","slug":"ad-bae-146-128-aft-fuselage-skin-under-apu-heat-shield","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":65588,"registerId":"commonwealth-F2007L01348-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"British Aerospace BAe 146 Series Aeropla","sectionType":"division","heading":"British Aerospace BAe 146 Series Aeroplanes","content":"### British Aerospace BAe 146 Series Aeroplanes\n\n| AD/BAe 146/128 | Aft Fuselage Skin under APU Heat Shield | 6/2007 |\n| -------------- | --------------------------------------- | ------ |\n\n| Applicability: | All Model BAe 146 and AVRO 146-RJ aircraft, all serial numbers.                                                                                                                                                                                                                                                                                                                                       |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Perform a detailed visual inspection in accordance with paragraph 2C of BAE Systems Inspection Service Bulletin (ISB) 53-191 initial issue, or later EASA approved revision.If corrosion is found during any inspection, before further flight, repair the affected area in accordance with paragraph 2D of ISB 53-191 initial issue, or later EASA approved revision.Note: EASA AD 2007-0075 refers. |\n| Compliance:    | Within one year after 7 June 2007, and thereafter at intervals not to exceed 2 years.The inspection interval may be extended to 4 years if the aircraft has been modified in accordance with BAE Systems Service Bulletin 53-193-60732A (Modification HCM60732A).                                                                                                                                     |\n|                | This Airworthiness Directive becomes effective on 7 June 2007.                                                                                                                                                                                                                                                                                                                                        |\n| Background:    | Corrosion has been found beneath the heat shield which is located around the APU exhaust outlet. Such corrosion could result in the fuselage being unable to sustain horizontal and vertical stabiliser loads, with potentially hazardous/catastrophic consequences.                                                                                                                                  |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n24 April 2007","sortOrder":0},{"sectionNumber":"AD/BAe 146/128","sectionType":"part","heading":"AD/BAe 146/128","content":"## AD/BAe 146/128","sortOrder":1},{"sectionNumber":"Aft Fuselage Skin under APU Heat Shield","sectionType":"part","heading":"Aft Fuselage Skin under APU Heat Shield","content":"## Aft Fuselage Skin under APU Heat Shield","sortOrder":2},{"sectionNumber":"6/2007","sectionType":"part","heading":"6/2007","content":"## 6/2007","sortOrder":3}],"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 provided text contains no indication that the AD's scope was altered from an earlier intent. It expressly applies to \"All Model BAe 146 and AVRO 146-RJ aircraft, all serial numbers\" and sets inspection and repair requirements and intervals (sources: Applicability; Requirement; Compliance)."},"complexity_factors":["Cross-reference to external technical documents: BAE Systems ISB 53-191 (paragraphs 2C/2D) and BAE SB 53-193-60732A (source: Requirement; Compliance).","Mandatory immediate action on positive findings: repairs must be completed before further flight (source: Requirement).","Inspection scheduling linked to modification status: standard 2‑year interval, extendable to 4 years only if specified modification is embodied (source: Compliance).","Universal applicability to all serial numbers increases administrative reach and fleet-wide implementation (source: Applicability).","Operational/technical judgment required to perform a 'detailed visual inspection' and to determine repair scope (source: Requirement specifying ISB procedures).","Must follow later EASA‑approved revisions of the ISB, introducing potential version-control compliance obligations (source: Requirement).","Safety consequence specificity (risk to stabiliser loads) raises priority and potential for immediate grounding if corrosion is found (source: Background)."],"plain_english_summary":"**What it does:** Requires operators of all BAe 146 / Avro 146‑RJ aircraft to carry out a detailed visual inspection of the aft fuselage beneath the APU heat shield and to repair any corrosion before further flight, following BAE Systems ISB 53‑191 (paras 2C/2D) or later EASA‑approved revisions.  \n**When it matters:** Inspections are due within one year after 7 June 2007 and then every 2 years (can be extended to 4 years if the aircraft is modified per SB 53‑193‑60732A). Corrosion there could compromise fuselage strength and stabiliser loads."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrowly-targeted airworthiness directive addressing a specific safety issue (corrosion under APU heat shield) on a specific aircraft type. The scope remains tightly focused on the original safety concern without expansion into broader operational or regulatory matters."},"complexity_factors":["Single, clearly defined applicability (all Model BAe 146 and AVRO 146-RJ aircraft)","Straightforward two-part requirement: inspect, and repair if needed","Simple compliance timeline with one extension condition","Only one external document reference (EASA AD 2007-0075) for context","No nested definitions, cross-references to other legislation, or conditional exceptions","Total length is approximately 200 words of substantive content"],"plain_english_summary":"CASA requires operators of BAe 146 and AVRO 146‑RJ jets to inspect the rear fuselage skin beneath the APU exhaust heat shield because corrosion has been found there. \n\nThis matters because unchecked corrosion could weaken the structure that supports the tail, risking catastrophic failure; the AD mandates recurring inspections and corrective repairs, affecting all Australian operators of these types."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-128-aft-fuselage-skin-under-apu-heat-shield","history":"/api/acts/ad-bae-146-128-aft-fuselage-skin-under-apu-heat-shield/history","analysis":"/api/acts/ad-bae-146-128-aft-fuselage-skin-under-apu-heat-shield/analysis","conflicts":"/api/acts/ad-bae-146-128-aft-fuselage-skin-under-apu-heat-shield/conflicts","importantCases":"/api/acts/ad-bae-146-128-aft-fuselage-skin-under-apu-heat-shield/important-cases","documents":"/api/acts/ad-bae-146-128-aft-fuselage-skin-under-apu-heat-shield/documents"}}