{"id":"F2006L02252","name":"AD/AMD 50/36 - Segregation of ADS/IRS Wiring","slug":"ad-amd-50-36-segregation-of-ads-irs-wiring","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":117578,"registerId":"commonwealth-F2006L02252-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AMD Falcon 50 and 900 Series Aeroplanes","sectionType":"division","heading":"AMD Falcon 50 and 900 Series Aeroplanes","content":"### AMD Falcon 50 and 900 Series Aeroplanes\n\n| AD/AMD 50/36 | Segregation of ADS/IRS Wiring | 8/2006 |\n| ------------ | ----------------------------- | ------ |\n\n| Applicability: | Falcon 900EX EASy S/N 97, 120 and subsequent (including S/N 601 & subsequent, also known as “DX” aeroplanes) |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. For F900EX EASy aeroplanes in the applicability range and without modification M5143 - Incorporate IRS 2 wiring modification M5143 and test the GP bus IRS entry in accordance with the accomplishment instructions of Service Bulletin SB-F900EX-274 or later revisions approved by the European Aviation Safety Agency (EASA). |\n| | 2. For all F900EX EASy aeroplanes in the applicability range - Amend the Falcon 900EX EASy Maintenance Manual to introduce MP 34-209 \"test of general purpose bus IRS entry\" at 5000 FH intervals by inserting Revision 2 of Chapter 5.40 into the manual. |\n| | 3. For all F900EX EASy aeroplanes in the applicability range - Amend the Minimum Equipment List (MEL) to reflect the dispatch conditions for ‘one IRS failure’ contained in the Dassault Aviation Master Minimum Equipment List temporary change TC 3. |\n| | Note: EASA AD 2006-0157 refers. |\n| Compliance: | For Requirements 1, 2 and 3 - At the earliest opportunity but no later than three months after the effective date of this Directive. |\n| | This Airworthiness Directive becomes effective on 3 August 2006. |\n| Background: | During a flight test performed on an EASy aircraft, and subsequent to an air data probe failure, the crew realized that the Flight path vectors and the Vertical speeds that were displayed on pilot's and co-pilot's PDU were identically wrong.A review of the EASy architecture reveals that the current wiring of Air Data System (ADS) and IRS units is not compliant with the certified safety objectives.All IRS primary inputs are wired to the same General Purpose (GP) Bus and thus the basic requirements for ADS segregation are not met. One single ADS unflagged air data error may lead to the computation and display on both pilot's and co-pilot's display units of unnoticed and misleading flight information. |\n\n| | At take-off or during go-around this situation might considerably reduce flight safety.This Directive mandates a wiring modification of IRS 2 and a test of General Purpose bus IRS entry. Furthermore in order to maintain ADS parameter segregation against possible failures, the Directive also requires operators to comply with the amendments made to Chapter 5.40 of Aircraft Maintenance Manuals that contain an additional periodic functional test of the IRS GP Bus I/O.Dispatch conditions under MMEL in case of an IRS2 failure are modified after implementation of the wiring change. |\n| --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n22 June 2006","sortOrder":0},{"sectionNumber":"AD/AMD 50/36","sectionType":"part","heading":"AD/AMD 50/36","content":"## AD/AMD 50/36","sortOrder":1},{"sectionNumber":"Segregation of ADS/IRS Wiring","sectionType":"part","heading":"Segregation of ADS/IRS Wiring","content":"## Segregation of ADS/IRS Wiring","sortOrder":2},{"sectionNumber":"8/2006","sectionType":"part","heading":"8/2006","content":"## 8/2006","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific wiring flaw discovered during flight testing. The scope remains precisely focused on the ADS/IRS segregation issue for the affected Falcon 900EX EASy aircraft. No scope creep is evident — the three requirements (wiring modification, maintenance procedure update, and MEL amendment) all directly address the identified safety risk without expanding into unrelated operational areas."},"complexity_factors":["Single-issue directive with only 3 specific requirements","Limited applicability (specific aircraft serial numbers only)","References external technical documents (Service Bulletin, Maintenance Manual, MMEL) but does not reproduce them","No nested exceptions or conditional logic — requirements apply uniformly to all affected aircraft","Short document (approximately 400 words of substantive content)","Only one defined term of note (\"GP Bus\" — General Purpose Bus, explained in context)","Clear compliance deadline with no alternative methods or escalations"],"plain_english_summary":"This AD requires owners/operators of certain Dassault Falcon 900EX EASy (SN 97, 120 and later; DX SN 601+) to fix a wiring defect that can let a single sensor fault feed identical, unflagged erroneous air data/attitude information to both pilots. It mandates a wiring modification to separate IRS/ADS buses, updates to maintenance procedures and the MEL, and testing — all to be done within three months of 3 August 2006 to prevent dual-display failures during critical flight phases."},"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 Directive changes the aircraft's operational and maintenance scope for affected Falcon 900EX EASy aeroplanes by mandating a wiring segregation modification, introducing a new recurring GP bus IRS functional test, and altering MEL dispatch conditions. It therefore amends both the physical configuration and the documented maintenance/dispatch regime where the prior wiring arrangement did not meet certified segregation objectives."},"complexity_factors":["Technical wiring modification (M5143) requiring shop capability and electrical integration work.","Mandated functional test of GP bus IRS entry referencing Service Bulletin SB-F900EX-274 (EASA approval dependency).","Amendment to the Maintenance Manual (Chapter 5.40) to add a periodic 5,000 flight‑hour test — procedural and recordkeeping changes for operators and maintainers.","Amendment to the Minimum Equipment List (MEL) to change dispatch conditions (MMEL temporary change TC 3) — operational and dispatch decision impacts.","Short compliance deadline (at the earliest opportunity but no later than three months) increasing scheduling pressure on operators and maintenance organisations.","Applicability limited to specific serial numbers and variants (identification and fleet management burden).","Interplay between maintenance actions, operational dispatch rules, and regulatory approval increases coordination complexity.","Testing and verification obligations may require specialised test equipment and trained personnel."],"plain_english_summary":"Requires a specific wiring modification (M5143) to IRS 2, a test of the General Purpose (GP) bus IRS entry per Dassault Service Bulletin SB-F900EX-274, a new periodic 5,000 flight‑hour IRS GP bus test in the Maintenance Manual, and an MEL amendment for dispatch with one IRS failure on specified Falcon 900EX EASy serial numbers. The regulator says this corrects non‑segregated ADS/IRS wiring that could let a single air‑data fault cause identical, misleading displays on both pilot and co‑pilot screens; operators must complete the work within three months."}},"importantCases":[],"_links":{"self":"/api/acts/ad-amd-50-36-segregation-of-ads-irs-wiring","history":"/api/acts/ad-amd-50-36-segregation-of-ads-irs-wiring/history","analysis":"/api/acts/ad-amd-50-36-segregation-of-ads-irs-wiring/analysis","conflicts":"/api/acts/ad-amd-50-36-segregation-of-ads-irs-wiring/conflicts","importantCases":"/api/acts/ad-amd-50-36-segregation-of-ads-irs-wiring/important-cases","documents":"/api/acts/ad-amd-50-36-segregation-of-ads-irs-wiring/documents"}}