{"id":"F2006L00141","name":"AD/EMB-120/40 - Elevator Torque Tubes","slug":"ad-emb-120-40-elevator-torque-tubes","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58025,"registerId":"commonwealth-F2006L00141-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Embraer EMB-120 (Brasilia) Series Aeropl","sectionType":"division","heading":"Embraer EMB-120 (Brasilia) Series Aeroplanes","content":"### Embraer EMB-120 (Brasilia) Series Aeroplanes\n\n| AD/EMB-120/40 | Elevator Torque Tubes | 2/2006 |\n| ------------- | --------------------- | ------ |\n\n| Applicability: | All Model EMB-120 aircraft.                                                                                                                                                                                             |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with Embraer Service Bulletin No. 120-55-0015 original issue, or later CTA approved revision.Note: CTA AD 2005-10-03 refers.                                                                       |\n| Compliance:    | Within 4,000 flight hours or 730 calendar days after 16 February 2006, whichever occurs first.                                                                                                                          |\n|                | This Airworthiness Directive becomes effective on 16 February 2006.                                                                                                                                                     |\n| Background:    | During scheduled maintenance on an EMB-120 aircraft, corrosion was detected on the inner surface of the elevator torque tubes. This condition can cause unbalance of the elevators and affect aircraft controllability. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n21 December 2005","sortOrder":0},{"sectionNumber":"AD/EMB-120/40","sectionType":"part","heading":"AD/EMB-120/40","content":"## AD/EMB-120/40","sortOrder":1},{"sectionNumber":"Elevator Torque Tubes","sectionType":"part","heading":"Elevator Torque Tubes","content":"## Elevator Torque Tubes","sortOrder":2},{"sectionNumber":"2/2006","sectionType":"part","heading":"2/2006","content":"## 2/2006","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive targeting a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined term implicitly referenced (CTA — Civil Aviation Authority, the predecessor to CASA)","Single, clear compliance pathway (follow the Embraer Service Bulletin)","Simple time-based compliance trigger (flight hours OR calendar days, whichever first)","No nested exceptions, conditional logic, or cross-references to other legislation beyond the single note about CTA AD 2005-10-03","Straightforward applicability (all Model EMB-120 aircraft — no exceptions or sub-models to parse)"],"plain_english_summary":"This mandatory Airworthiness Directive requires owners/operators of Embraer EMB-120 (Brasilia) aircraft to inspect and repair corrosion inside the elevator torque tubes per Embraer Service Bulletin No. 120-55-0015 (or CASA‑approved later revisions). Corroded torque tubes can unbalance elevators and impair control, posing a serious safety risk. Compliance is required within 4,000 flight hours or 730 days after 16 February 2006; noncompliance prohibits legal flight."},"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 AD addresses corrosion on elevator torque tubes by imposing inspections/repairs on all EMB-120 aircraft in line with the stated purpose. The instrument does not expand or narrow applicability beyond all Model EMB-120 aircraft, nor does the text indicate a change from the stated objective of correcting detected corrosion (Applicability; Requirement; Background)."},"complexity_factors":["Single, clear applicability: all Model EMB-120 aircraft (Applicability).","Mandates compliance with an external Embraer Service Bulletin or later CTA‑approved revision, requiring operators to track revisions and obtain approvals (Requirement).","Fixed dual compliance deadline: 4,000 flight hours or 730 calendar days from the effective date, creating scheduling pressures (Compliance).","Operational and financial burden on aircraft operators for inspections and potential repairs or replacements; potential aircraft downtime (Compliance; Background).","Safety-critical consequence (elevator unbalance affecting controllability) increases priority and may require immediate remedial work if defects are found (Background).","Regulatory discretion: allows CTA approval of later revisions, introducing an approval step and possible variability in accepted corrective actions (Requirement).","AD references SB for technical detail rather than providing methods, creating dependence on manufacturer documentation for implementation (Requirement)."],"plain_english_summary":"This Airworthiness Directive requires all Embraer EMB-120 operators to inspect and, if necessary, repair or replace elevator torque tubes in accordance with Embraer Service Bulletin No. 120-55-0015 (or a later CTA‑approved revision) (Requirement). The work must be completed within 4,000 flight hours or 730 days from 16 February 2006; CASA issued the AD after corrosion was found on torque‑tube inner surfaces, so operators bear inspection and repair costs and must schedule maintenance to mitigate controllability risk (Compliance; Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-120-40-elevator-torque-tubes","history":"/api/acts/ad-emb-120-40-elevator-torque-tubes/history","analysis":"/api/acts/ad-emb-120-40-elevator-torque-tubes/analysis","conflicts":"/api/acts/ad-emb-120-40-elevator-torque-tubes/conflicts","importantCases":"/api/acts/ad-emb-120-40-elevator-torque-tubes/important-cases","documents":"/api/acts/ad-emb-120-40-elevator-torque-tubes/documents"}}