{"id":"F2006B02377","name":"AD/AMD 50/10 Amdt 1 - Overhead Panel Wiring Harness","slug":"ad-amd-50-10-amdt-1-overhead-panel-wiring-harness","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41607,"registerId":"commonwealth-F2006B02377-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AMD 50/10 Amdt 1 - Overhead Panel Wiring Harness","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nAMD Falcon 50 and 900 Series Aeroplanes\n\nAD/AMD 50/10\n\nAmdt 1\n\n  \nOverhead Panel Wiring Harness 7/96\n\nApplicability: All Falcon 900 series aircraft.\n\nRequirement: 1. Check the condition and correct run of the wiring harness connected to the overhead panel in accordance with Dassault Aviation Alert Service Bulletin F.900- A172 dated 11 October 1995. If the cables are found to be damaged then carry out Dassault Aviation Service Bulletin F.900-173 dated 11 October 1995.\n\n2. Install insulating protectors on both ceiling headliner grounding modules in accordance with Dassault Aviation Service Bulletin F900-174 dated 3 April 1996.\n\nNote: DGAC Airworthiness Directive 95-204-016(B)R1 dated 27 March 1996 refers.\n\nCompliance: For Requirement 1 \\- This compliance remains unchanged as \\`Unless already accomplished, prior to 1 February 1996'.\n\nFor Requirement 2 \\- Either prior to 30 April 1997 or prior to the accumulation of 600 hours time in service after 20 June 1996, whichever occurs first.\n\nBackground: During start, a Falcon 900 crew was unable to connect battery No 1: every attempt to connect it led to the tripping of battery circuit breaker (19P1) on the GPA main electrical box.\n\nInvestigations revealed that a wire from the overhead panel NORM/EXT.POWER selector (3PE) was interfering with one of the two grounding modules located behind the panel. This caused a wire to short to ground.\n\nThis amendment introduces measures designed to prevent chaffing caused by interference between the overhead panel wiring harness and the grounding modules.\n\nThe original issue of this Airworthiness Directive became effective on 1 February 1996.","sortOrder":0}],"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":3,"scope_assessment":{"changed":true,"description":"This amendment expanded the original directive by adding a preventive installation requirement (Requirement 2: fit insulating protectors to ceiling headliner grounding modules) in addition to the original inspection/repair requirement (Requirement 1). It also specifies a new compliance window for the protector installation (either before 30 April 1997 or before accumulation of 600 flight hours after 20 June 1996). In short, the AD moved from a reactive inspection/repair mandate to include an affirmative modification intended to prevent recurrence of the fault."},"complexity_factors":["Short instrument with only two substantive requirements","Three external service bulletins referenced (inspection, repair, protector installation)","Two different compliance timings, including a 'whichever occurs first' condition","Cross-reference to a foreign airworthiness directive (DGAC) for context","Technical detail delegated to external service bulletins (requires consulting those documents)"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Applies to: all Dassault Falcon 900 series aircraft (operators, owners and maintenance organisations).  (Applicability)\n\n- Two mandatory actions are required:  \n  1. Inspect the wiring harness that connects to the overhead panel and check its routing, and repair any damaged cables. The inspection and any repairs must be carried out in accordance with Dassault Aviation Alert Service Bulletin F.900-A172 (inspection) and, if damage is found, Dassault Aviation Service Bulletin F.900-173 (repair). (Requirement 1)\n  2. Fit insulating protectors to both ceiling headliner grounding modules behind the overhead panel, in accordance with Dassault Aviation Service Bulletin F900-174. (Requirement 2)\n\n- Deadlines (as written):  \n  - Requirement 1: \"Unless already accomplished, prior to 1 February 1996.\"  \n  - Requirement 2: install either before 30 April 1997 or before accumulating 600 hours time-in-service after 20 June 1996, whichever occurs first. (Compliance)\n\n**Why the rule was introduced (background and effect)**\n\n- The immediate technical problem: during engine start on a Falcon 900, attempts to connect battery No. 1 repeatedly tripped the battery circuit breaker. Investigation showed a wire from the overhead-panel selector was contacting a grounding module behind the panel and shorting to ground. The measures required by this instrument are designed to stop the overhead-panel wiring harness from chafing against or contacting those grounding modules.\n\n**Who pays, who decides, and what behaviour changes**\n\n- Who pays: aircraft operators and their maintenance organisations pay for the inspection, any repairs, parts (insulating protectors) and the labour and downtime needed to carry out the service-bulletin work.  \n- Who decides/how it is done: work must be done in accordance with the referenced Dassault service/alert service bulletins; the operator or its approved maintenance organisation implements the actions. Regulatory force comes from the airworthiness directive—compliance is required for continued legal operation.  \n- Behaviour change: maintenance schedules must include the inspection and, where necessary, repair work; operators must procure and fit insulating protectors within the compliance window and document the work for continuing airworthiness records.\n\n**Costs, incentives and trade-offs**\n\n- Costs: direct, concentrated costs fall on Falcon 900 operators (parts, labour, aircraft downtime). Maintenance providers get the work revenue.  \n- Incentives: the rule lowers the probability of electrical faults (shorts/tripping circuit breakers) caused by harness-to-grounding-module interference. That reduces the operator’s risk of in-service electrical interruptions but comes at the maintenance cost.  \n- Implementation risk and compliance burden: the AD relies on multiple external service bulletins whose technical detail is not reproduced here. Operators must access those documents, follow their instructions precisely, and keep records. There is limited operator discretion because the AD prescribes actions to the service-bulletin standard.\n\n**Other practical points**\n\n- The AD references a DGAC (French authority) airworthiness directive; the AD therefore tracks work already required or recommended by the airworthiness authority of the aircraft’s country of design.  \n- The measure is narrowly targeted: it addresses a specific wiring-route/chafing risk behind the overhead panel rather than a broader electrical-system redesign.  \n\n(References in the instrument: Dassault Aviation Alert Service Bulletin F.900-A172 dated 11 Oct 1995; Dassault Aviation Service Bulletin F.900-173 dated 11 Oct 1995; Dassault Aviation Service Bulletin F900-174 dated 3 Apr 1996; DGAC AD 95-204-016(B)R1 dated 27 Mar 1996.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope — addressing a specific wiring safety issue in Falcon 900 aircraft. The amendment (Amdt 1) adds the second requirement (insulating protectors) but this is a logical extension of the original safety purpose rather than scope creep. The document remains focused on the single technical issue of overhead panel wiring interference."},"complexity_factors":["Very short document (under 300 words)","Only 2 substantive requirements with clear compliance dates","Minimal defined terms (only standard aviation terminology like 'time in service')","No nested conditional logic or cross-references to other legislation","References to external technical documents (Service Bulletins) rather than internal legislative complexity","Single amendment tracking (Amdt 1) with straightforward background explanation"],"plain_english_summary":"This airworthiness safety order for Dassault Falcon 900 series aircraft requires owners/operators to inspect and, if needed, repair wiring behind the cockpit overhead panel and to fit insulating covers on two ceiling grounding modules to stop wire chafing that can cause electrical shorting and battery/circuit failures. Compliance deadlines: wiring check by 1 Feb 1996; insulation by 30 Apr 1997 or before 600 flight hours after 20 Jun 1996."}},"importantCases":[],"_links":{"self":"/api/acts/ad-amd-50-10-amdt-1-overhead-panel-wiring-harness","history":"/api/acts/ad-amd-50-10-amdt-1-overhead-panel-wiring-harness/history","analysis":"/api/acts/ad-amd-50-10-amdt-1-overhead-panel-wiring-harness/analysis","conflicts":"/api/acts/ad-amd-50-10-amdt-1-overhead-panel-wiring-harness/conflicts","importantCases":"/api/acts/ad-amd-50-10-amdt-1-overhead-panel-wiring-harness/important-cases","documents":"/api/acts/ad-amd-50-10-amdt-1-overhead-panel-wiring-harness/documents"}}