{"id":"F2010L00148","name":"AD/EMB-120/11 Amdt 2 - AHRS Power Interruption","slug":"ad-emb-120-11-amdt-2-ahrs-power-interruption","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":122914,"registerId":"commonwealth-F2010L00148-current","compilationNumber":null,"startDate":"2026-04-03","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-120/11 Amdt 2 | AHRS Power Interruption | 2/2010 |\n| -------------------- | ----------------------- | ------ |\n\n| Applicability: | Brasilia EMB-120, EMB-120RT and EMB-120ER all aircraft through to serial number 120291 inclusive.                                                                                                                                                                                                                                                                                                                                                                                          |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Action in accordance with Embraer Service Bulletin (SB) 120-024-0008 revision 3 or later approved revisions.Note 1: Compliance in accordance with the SB constitutes terminating action for the requirements of the CTA 94-03-01R1.Note 2: CTA (Brazil) AD 94-03-01R1 Amdt 39-738 refers.                                                                                                                                                                                                  |\n| Compliance:    | By 19 February 2010, unless previously accomplished.                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n|                | This Amendment becomes effective on 20 January 2010.                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n| Background:    | The CTA has received a report of erroneous heading information being displayed on both EHSIs following certain combinations of electrical system failures, which are not considered improbable.The original issue of the Directive provided temporary procedures which ensured that heading information was available following these failuresAmendment 1 provided terminating action for the temporary procedures.This amendment introduces the use of later revisions of the Embraer SB. |\n\n![](image.001.png)\n\nMike Higgins  \nDelegate of the Civil Aviation Safety Authority\n\n19 January 2010","sortOrder":0},{"sectionNumber":"AD/EMB-120/11 Amdt 2","sectionType":"part","heading":"AD/EMB-120/11 Amdt 2","content":"## AD/EMB-120/11 Amdt 2","sortOrder":1},{"sectionNumber":"AHRS Power Interruption","sectionType":"part","heading":"AHRS Power Interruption","content":"## AHRS Power Interruption","sortOrder":2},{"sectionNumber":"2/2010","sectionType":"part","heading":"2/2010","content":"## 2/2010","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 2 changes the permitted compliance mechanism by explicitly allowing later approved revisions of Embraer SB 120-024-0008 as acceptable terminating action. It does not alter the aircraft applicability or the compliance deadline; it widens the set of approved SB revisions rather than expanding the population of affected aircraft or adding new types of mandatory work."},"complexity_factors":["Serial-number-limited applicability (up to 120291) requires operators to check fleet identity before applying the AD.","Mandates incorporation of a manufacturer Service Bulletin (SB 120-024-0008 rev 3 or later) — operators must obtain, interpret and implement the SB.","Reference to ‘later approved revisions’ creates regulatory discretion about which future SB revisions qualify as compliance.","Interplay with earlier temporary procedures and CTA AD 94-03-01R1 requires traceability to show terminating action has been achieved.","Fixed compliance deadline (19 February 2010) imposes scheduling and maintenance-planning pressure on operators.","Technical focus on AHRS/electrical system failures means work will involve avionics maintenance and possible aircraft downtime."],"plain_english_summary":"This amendment requires operators of Embraer EMB-120 series aeroplanes (serial numbers through 120291) to implement the modification in Embraer Service Bulletin 120‑024‑0008 revision 3 or any later approved revision to stop erroneous heading indications after certain electrical failures. CASA set a compliance deadline of 19 February 2010 (effective 20 January 2010).\n\nComplying with the service bulletin is declared terminating action for prior temporary procedures and links to the Brazilian CTA AD 94‑03‑01R1."},"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":2,"scope_assessment":{"changed":false,"description":"This is Amendment 2 to an existing Airworthiness Directive. The scope remains tightly focused on the original safety issue (AHRS power interruption causing erroneous heading displays). The amendment simply updates the acceptable revision of the manufacturer service bulletin (from earlier revisions to revision 3 or later), which is a standard maintenance update rather than an expansion of scope."},"complexity_factors":["Single, specific technical requirement referencing an external manufacturer document (Embraer Service Bulletin)","Limited applicability (one aircraft type, specific serial number range)","No nested conditional logic or exceptions within the directive itself","Only 2 brief notes providing cross-references to related Brazilian aviation authority documents","Straightforward compliance deadline with single date","Total length is approximately 200 words of substantive content"],"plain_english_summary":"This CASA airworthiness directive requires operators of Embraer EMB-120 (including RT and ER) aircraft with serial numbers up to 120291 to carry out the repair in Embraer Service Bulletin 120-024-0008 (rev 3 or later) by 19 February 2010 to fix an AHRS electrical fault that can make both heading displays show incorrect information.\n\nThe mandate prevents potentially hazardous navigation errors by making the manufacturer’s safety fix mandatory and accepts later SB revisions where applicable."}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-120-11-amdt-2-ahrs-power-interruption","history":"/api/acts/ad-emb-120-11-amdt-2-ahrs-power-interruption/history","analysis":"/api/acts/ad-emb-120-11-amdt-2-ahrs-power-interruption/analysis","conflicts":"/api/acts/ad-emb-120-11-amdt-2-ahrs-power-interruption/conflicts","importantCases":"/api/acts/ad-emb-120-11-amdt-2-ahrs-power-interruption/important-cases","documents":"/api/acts/ad-emb-120-11-amdt-2-ahrs-power-interruption/documents"}}