{"id":"F2008L02103","name":"AD/ERJ-170/4 Amdt 4 - Flight Guidance Control Unit","slug":"ad-erj-170-4-amdt-4-flight-guidance-control-unit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74327,"registerId":"commonwealth-F2008L02103-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Embraer ERJ-170 Series Aeroplanes","sectionType":"division","heading":"Embraer ERJ-170 Series Aeroplanes","content":"### Embraer ERJ-170 Series Aeroplanes\n\n| AD/ERJ-170/4 Amdt 4 | Flight Guidance Control Unit | 8/2008 DM |\n| ------------------- | ---------------------------- | --------- |\n\n| Applicability: | ERJ 170 model aeroplanes equipped with Primus EPIC software load version 17.3, 17.4, 17.5, 17.6 or 17.7. |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Carry out a functional test to check the engagement of the Flight Guidance Control System (FGCS) channels in accordance with Embraer Service Bulletin (SB) 170-22-0003, original issue, dated 9 November 2006 or further revisions approved by the Brazilian Agência Nacional de Avição Civil (ANAC). |\n| | Note 1: For the purpose of this Directive, a functional check is defined as: \"A quantitative check to determine if one or more functions of an item perform within specified limits.” |\n| | Functional tests accomplished in accordance with earlier issues of this Directive are acceptable for compliance with Requirement 1 of this Amendment. |\n| | 2. Install either Primus EPIC software load version 19.3 in accordance with Embraer SB 170-31-0019 original issue, dated 3 May 2007, or further revisions approved by the ANAC; or a higher software load version in accordance with an Embraer SB approved by the ANAC. |\n| | Note 2: For example version 19.4 may be installed in accordance with SB170-31-0026 dated 5 October 2007 or version 21.2 may be installed in accordance with SB 170-31-0028 Revision 01 dated 14 January 2008, other versions may be installed in accordance with an applicable approved SB. |\n| | Note 3: The installation of the Primus EPIC software load version 19.3 or higher is considered a terminating action for the Requirement 1 repetitive functional check. |\n| | Note 4: ANAC AD 2006-11-02R3 refers. |\n| Compliance: | For Requirement 1 - Within the next 300 hours time in service (TIS), after the first issue of an Australian Certificate of Airworthiness, and thereafter, at intervals that do not exceed 600 hours TIS until Requirement 2 is accomplished. |\n| | For Requirement 2 - No later than 30 June 2009. |\n\n| | This Amendment becomes effective on 18 June 2008. |\n| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Background: | The ANAC has received reports that some “caution” messages issued by the FGCS are not displayed on aircraft equipped with EPIC software load 17.3, 17.4, 17.5, 17.6 or 17.7. Therefore, following a possible failure on one FGCS channel during a given flight, such a failure condition will remain undetected or latent in subsequent flights. If another failure occurs on the second FGCS channel, the result may be a command hard-over by the autopilot. |\n| | Since this condition may affect the safety of the aeroplane, the original issue of this Directive required the repetitive functional testing of the FGCS. |\n| | Amendment 1 continued the repetitive inspection requirement until software load version 19.3 or higher was installed. |\n| | Amendment 2, whilst continuing the initial repetitive inspection requirement and the additional terminating requirement, introduced by Amendment 1, changed the applicability of the Directive following similar action by the Brazilian ANAC. |\n| | Amendment 3, whilst continuing the initial repetitive inspection requirement and the additional terminating requirement introduced by Amendment 1, clarified how higher load versions of the Primus EPIC software may be installed. |\n| | This Amendment continues the repetitive inspection requirement but extends the terminating action date by 12 months. |\n| | The original issue of this Directive became effective on 4 April 2007. |\n| | Amendment 1 became effective on 19 October 2007. |\n| | Amendment 2 became effective on 2 November 2007. |\n| | Amendment 3 became effective on 5 June 2008. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n12 June 2008","sortOrder":0},{"sectionNumber":"AD/ERJ-170/4 Amdt 4","sectionType":"part","heading":"AD/ERJ-170/4 Amdt 4","content":"## AD/ERJ-170/4 Amdt 4","sortOrder":1},{"sectionNumber":"Flight Guidance Control Unit","sectionType":"part","heading":"Flight Guidance Control Unit","content":"## Flight Guidance Control Unit","sortOrder":2},{"sectionNumber":"8/2008 DM","sectionType":"part","heading":"8/2008 DM","content":"## 8/2008 DM","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":5,"scope_assessment":{"changed":true,"description":"This Amendment keeps the original repetitive inspection obligation for specified EPIC software loads but extends the terminating-action date by 12 months and reaffirms acceptable higher software-load installations as the way to end repetitive checks. Applicability remains tied to aircraft with EPIC loads 17.3–17.7 (Applicability; Requirement 1–2; Background), while the Compliance timing and terminating deadline have been adjusted (Compliance: hours and calendar deadline)."},"complexity_factors":["Narrow technical scope limited to ERJ-170s with specified Primus EPIC software loads (Applicability).","Two-tier action structure: repetitive functional testing requirement and a terminating action (Requirement 1 and Requirement 2).","Time-based compliance schedule tied to flight hours and a calendar deadline (Compliance: 300/600 hours; install by 30 June 2009).","Multiple acceptable software versions and several alternative SBs for installation increase implementation choices (Requirement 2, Notes 2–3).","Reliance on external regulator approvals for service bulletin revisions (Brazilian ANAC approval referenced in Requirement 1 and Requirement 2).","Record‑keeping and operational monitoring burden to track hours-in-service and recurring test intervals (Compliance).","History of prior amendments and an explicit 12‑month extension of the terminating action date complicate regulatory continuity (Background).","Terminating action creates a clear incentive to upgrade software (operational cost vs. recurring test burden).","Delegated administrative authority for issuance and effective dates noted (signature by CASA delegate)."],"plain_english_summary":"Requires operators of Embraer ERJ-170 aircraft with Primus EPIC software loads 17.3–17.7 to carry out recurring functional checks of the Flight Guidance Control System until the aircraft’s Primus EPIC is upgraded to version 19.3 or higher; installing the upgrade terminates the repetitive checks. The measure responds to ANAC reports that certain FGCS caution messages were not displayed, creating a risk that a latent channel failure plus a second failure could cause an autopilot hard-over."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original directive (April 2007) was a straightforward safety fix requiring repetitive testing until a software upgrade. Through four amendments, the scope has expanded from a simple testing mandate to a complex, time-extended compliance regime with multiple approved upgrade paths, external regulatory dependencies (ANAC), and evolving deadlines. The terminating action deadline has been pushed back by at least 12 months from the original schedule, and the installation options have broadened to include 'higher versions' approved by foreign regulators rather than a single specified version."},"complexity_factors":["Multiple amendment history requiring cross-referencing (original issue plus Amendments 1-4)","Technical aviation terminology requiring domain knowledge (FGCS, TIS, Primus EPIC, Service Bulletins)","Conditional compliance structure: Requirement 1 is repetitive until Requirement 2 is accomplished","External document dependencies: references to Brazilian ANAC approvals and Embraer Service Bulletins not contained in the instrument itself","Nested applicability criteria: specific aircraft model + specific software versions (17.3-17.7)","Dual-path compliance for Requirement 2 (version 19.3 via one SB, or higher versions via other SBs)"],"plain_english_summary":"This CASA Airworthiness Directive targets Embraer ERJ‑170s with Primus EPIC software versions 17.3–17.7. It requires functional testing of the Flight Guidance Control System every 600 flight hours until the software is upgraded to version 19.3 or later (compliance deadline 30 June 2009). A software bug can hide a single‑channel failure and, if a second channel fails, allow a sudden autopilot \"hard‑over,\" risking loss of control. It affects Australian operators and foreign aircraft operating in Australian airspace."}},"importantCases":[],"_links":{"self":"/api/acts/ad-erj-170-4-amdt-4-flight-guidance-control-unit","history":"/api/acts/ad-erj-170-4-amdt-4-flight-guidance-control-unit/history","analysis":"/api/acts/ad-erj-170-4-amdt-4-flight-guidance-control-unit/analysis","conflicts":"/api/acts/ad-erj-170-4-amdt-4-flight-guidance-control-unit/conflicts","importantCases":"/api/acts/ad-erj-170-4-amdt-4-flight-guidance-control-unit/important-cases","documents":"/api/acts/ad-erj-170-4-amdt-4-flight-guidance-control-unit/documents"}}