{"id":"F2008L00495","name":"AD/J4100/6 - Wing Upper Splice Plate","slug":"ad-j4100-6-wing-upper-splice-plate","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":119313,"registerId":"commonwealth-F2008L00495-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"BAe Systems (Operations) Jetstream 4100 ","sectionType":"division","heading":"BAe Systems (Operations) Jetstream 4100 Series Aeroplanes","content":"### BAe Systems (Operations) Jetstream 4100 Series Aeroplanes\n\n| AD/J4100/6 | Wing Upper Splice Plate | 4/2008 DM |\n| ---------- | ----------------------- | --------- |\n\n| Applicability: | All Model Jetstream Series 4100 aircraft, construction numbers 41004 through 41096, and 41102 through 41004, on which either:Service Bulletin (SB) J41-57-019 or equivalent inspection has not been carried out; or,SB J41-57-019 or equivalent inspection has been carried out and the wing upper splice plates have an eddy current reading of less than 35.0% IACS.Note: Aircraft construction numbers 41097 through 41001 were inspected during production and do not require additional action. |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Accomplish an eddy current inspection of the wing upper splice plate part number 14157126-3 in accordance with the instructions of British Aerospace Regional Aircraft SB J41-57-019 original issue, or Revision 1, or later EASA approved revision; or using an equivalent approved procedure.Note 1: Wing upper splice plates that have an eddy current reading at or above 35.0% IACS require no further action.2. On aircraft that have an eddy current reading of less than 35.0% IACS, accomplish the borescope inspection of the wing upper splice plate part number 14157126-3 in accordance with paragraphs 2.A. and 2.B. of BAE Systems (Operations) Limited SB J41-57-020 Revision 1, or later EASA approved revision.3. When no corrosion is found, re-inspect the wing upper splice plate part number 14157126-3 in accordance with paragraph 2.B. of BAE Systems (Operations) Limited SB J41-57-020 Revision 1, or later EASA approved revision.4. When corrosion is found that is less than the limits specified in Figure 1 of SB J41-57-020 Revision 1, or later EASA approved revision, re-inspect the wing upper splice plate part number 14157126-3 in accordance with paragraph 2.B. of BAE Systems (Operations) Limited SB J41-57-020 Revision 1, or later EASA approved revision.5. When corrosion is found that is outside the acceptable limits, either replace the wing upper splice plate in accordance with SB J41-57-021 Revision 1, or later EASA approved revision, or repair the wing upper splice plate in accordance with a repair approved by EASA.Note 2: Installing a replacement wing upper splice plate part number 14157126-3PF in accordance with SB J41-57-021 Revision 1, or later EASA approved revision, provides terminating action for the repeat inspections of Requirements 3 or 4, as applicable.Note 3: EASA AD 2007-0056 refers. |\n| Compliance: | 1. Within 3 months after 20 February 2008, unless already accomplished.2. Before further flight after the Requirement 1 inspection.3. At intervals not to exceed 12 months.4. At intervals not to exceed 12 months and, within 3 years of the corrosion being discovered, replace the wing upper splice plate in accordance with SBJ41-57-021 Revision 1, or later EASA approved revision.5. Before further flight. |\n| | This Airworthiness Directive becomes effective on 20 February 2008. |\n| Background: | A report was received of corrosion of the wing upper splice plate detected during a routine four year structural inspection of an in-service aircraft. Investigation revealed that the susceptibility of the wing upper splice plate to corrosion was linked to the material conductivity. Revision 1 of SB J41-57-020 extends applicability to include aircraft construction numbers 41102 through 41104. |\n\n![](image.001.png) \nDavid Villiers \nDelegate of the Civil Aviation Safety Authority\n\n15 February 2008","sortOrder":0},{"sectionNumber":"AD/J4100/6","sectionType":"part","heading":"AD/J4100/6","content":"## AD/J4100/6","sortOrder":1},{"sectionNumber":"Wing Upper Splice Plate","sectionType":"part","heading":"Wing Upper Splice Plate","content":"## Wing Upper Splice Plate","sortOrder":2},{"sectionNumber":"4/2008 DM","sectionType":"part","heading":"4/2008 DM","content":"## 4/2008 DM","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Applicability was expanded: Revision 1 of SB J41-57-020 extended the AD to include construction numbers 41102 through 41104. The AD also notes that certain aircraft (construction numbers 41097 through 41001) were inspected in production and are exempt. Procedures and acceptable actions are tied to specific SB revisions but may be carried out using later EASA‑approved revisions, so procedural scope can change as new EASA-approved revisions are issued (see Requirements and Notes)."},"complexity_factors":["Technical inspection methods required (eddy-current and borescope testing) and a numeric threshold (35.0% IACS) for follow-up actions","Multiple conditional outcomes (no action, repeat inspection, repair, or replacement) depending on test results","References to specific manufacturer Service Bulletins (SB J41-57-019, SB J41-57-020, SB J41-57-021) and requirement that later EASA-approved revisions may be used","Applicability tied to specific construction-number ranges with production-inspected aircraft exempted","Compliance timetable with varied deadlines (within 3 months, before next flight, recurring 12‑month intervals, and a 3‑year replacement deadline for certain corrosion findings)","Requirement for repairs to be approved by EASA or carried out per a specific SB, adding regulator and approval-process dependence"],"plain_english_summary":"This Airworthiness Directive requires operators of specified BAe Jetstream 4100-series aircraft to inspect the wing upper splice plate using eddy-current testing and, if conductivity is below the stated threshold, borescope inspection and repeat monitoring or repair/replacement under approved procedures. It applies to defined construction-number ranges and creates mandatory inspection intervals and corrective-action deadlines for owners/operators and maintenance organisations to address corrosion linked to material conductivity."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with focused scope. It addresses a specific safety issue (corrosion in wing splice plates) for a specific aircraft type. The scope remains tightly constrained to the identified safety risk and does not appear to have expanded beyond the original technical safety purpose."},"complexity_factors":["Multiple conditional pathways (5 different requirements depending on inspection results and aircraft history)","Cross-references to external technical documents (Service Bulletins J41-57-019, J41-57-020, and J41-57-021) without reproducing their content","Technical aviation terminology requiring specialized knowledge (eddy current inspection, borescope, IACS conductivity units, construction numbers)","Nested compliance deadlines (immediate, 3 months, 12-month intervals, 3-year replacement deadline)","Specific part numbers and revision tracking (must use specific SB revisions or 'later EASA approved revisions')","Applicability determination requires checking multiple conditions (construction number ranges AND inspection history AND conductivity readings)"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspections of the wing upper splice plate on BAe Jetstream 4100s after corrosion was found. Owners must use eddy‑current testing and, if conductivity is low, borescope checks; consequences range from recurring inspections to mandatory repair or replacement, while fitting the specified replacement part (‑3PF) eliminates repeat inspections. It affects most Jetstream 4100 operators and prevents undetected corrosion that could weaken the wing and risk structural failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-j4100-6-wing-upper-splice-plate","history":"/api/acts/ad-j4100-6-wing-upper-splice-plate/history","analysis":"/api/acts/ad-j4100-6-wing-upper-splice-plate/analysis","conflicts":"/api/acts/ad-j4100-6-wing-upper-splice-plate/conflicts","importantCases":"/api/acts/ad-j4100-6-wing-upper-splice-plate/important-cases","documents":"/api/acts/ad-j4100-6-wing-upper-splice-plate/documents"}}