{"id":"F2007L04694","name":"AD/CESSNA 525/6 - Electrical Power - Relay Circuit Protection","slug":"ad-cessna-525-6-electrical-power-relay-circuit-protection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":71138,"registerId":"commonwealth-F2007L04694-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Cessna 525 Series Aeroplanes","sectionType":"division","heading":"Cessna 525 Series Aeroplanes","content":"### Cessna 525 Series Aeroplanes\n\n| AD/CESSNA 525/6 | Electrical Power - Relay Circuit Protection | 2/2008 DM |\n| --------------- | ------------------------------------------- | --------- |\n\n| Applicability: | Model 525B aeroplanes, serial numbers 0001 through 0013 inclusive.                                                                                                                                                                                                                     |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Unless already accomplished, incorporate electrical power relay circuit protection kit part number (P/N) SB525B-24-02 by following Cessna Citation Service Bulletin SB525B-24-02 Revision 1 dated 4 October 2007.                                                                      |\n|                | Later revisions of the above SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-23-16, are considered acceptable for compliance with the equivalent Requirements of this Directive.                    |\n|                | Note: FAA AD 2007-23-16 Amdt 39-15262 refers.                                                                                                                                                                                                                                          |\n| Compliance:    | Either before 18 January 2008 or within the next 10 hours time-in-service after 19 December 2007, whichever occurs first.                                                                                                                                                              |\n|                | This Airworthiness Directive becomes effective on 19 December 2007.                                                                                                                                                                                                                    |\n| Background:    | The FAA has received a report of a Model 525B aeroplane experiencing in-flight loss of numerous systems, tripped circuit breakers, together with burned wiring adjacent to the power distribution panel, this was a result of aircraft wiring left unprotected in the original design. |\n|                | This Directive requires an electrical power relay circuit protection kit P/NSB525B-24-02 to be installed and is issued to correct an incorrect wiring installation and to provide short-circuit protection for all wiring from the aircraft power distribution system.                 |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n7 December 2007","sortOrder":0},{"sectionNumber":"AD/CESSNA 525/6","sectionType":"part","heading":"AD/CESSNA 525/6","content":"## AD/CESSNA 525/6","sortOrder":1},{"sectionNumber":"Electrical Power - Relay Circuit Protect","sectionType":"part","heading":"Electrical Power - Relay Circuit Protection","content":"## Electrical Power - Relay Circuit Protection","sortOrder":2},{"sectionNumber":"2/2008 DM","sectionType":"part","heading":"2/2008 DM","content":"## 2/2008 DM","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific wiring defect in a limited fleet. The scope remains precisely focused on the original safety issue — correcting unprotected wiring in the power distribution system of early production Cessna 525B aircraft. There is no evidence of scope creep or expansion beyond the original safety purpose."},"complexity_factors":["Single, specific technical requirement (install one specific kit)","Limited applicability (only 13 specific aircraft by serial number)","One main compliance pathway with a single alternative (FAA-approved AMOC)","Simple deadline structure (date OR flight hours, whichever first)","No nested definitions, cross-references to other legislation, or conditional exceptions","Document is approximately 200 words excluding formatting artifacts"],"plain_english_summary":"This AD mandates installation of Cessna kit SB525B-24-02 to add wiring protection on Cessna 525B aircraft serials 0001–0013, addressing an unprotected wiring design that led to in-flight breaker trips, burned wiring and multiple system failures (per FAA report). It affects owners, operators and maintenance organisations of those 13 jets. The AD is effective 19 Dec 2007; compliance is required by 18 Jan 2008 or within 10 flight hours after 19 Dec 2007, whichever comes first."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive does not expand or narrow the affected fleet beyond the stated applicability: it mandates installation of kit P/N SB525B-24-02 on Model 525B aeroplanes s/n 0001–0013. Flexibility is provided only for later Cessna SB revisions if approved by the FAA as AMOCs; the basic scope and required remedy remain the same (Applicability; Requirement)."},"complexity_factors":["Narrow applicability to a small set of serial numbers (Model 525B s/n 0001–0013) reduces administrative scope but concentrates costs (Applicability).","Technical work involves aircraft power distribution wiring and installation of a protection kit, requiring qualified maintenance action (Requirement; Background).","Tight compliance window tied to calendar dates and limited flight hours creates scheduling pressure for operators (Compliance).","Regulatory coordination: later service bulletin revisions are acceptable only if the FAA approves them as Alternate Methods of Compliance (AMOC), so regulator approval affects acceptable fixes (Requirement).","Reference to FAA AD 2007-23-16 means convergence with an overseas regulator’s findings and previous incident reports (Requirement; Note; Background)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of Cessna 525B aeroplanes (serial numbers 0001–0013) to install an electrical power relay circuit protection kit (P/N SB525B-24-02) per Cessna Service Bulletin SB525B-24-02 Rev 1 to add short-circuit protection and correct incorrect wiring. Compliance is required by 18 January 2008 or within 10 flight hours after 19 December 2007, whichever occurs first. Owners/operators bear the cost and must arrange mechanical wiring work; the FAA may accept later SB revisions as alternate methods of compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-525-6-electrical-power-relay-circuit-protection","history":"/api/acts/ad-cessna-525-6-electrical-power-relay-circuit-protection/history","analysis":"/api/acts/ad-cessna-525-6-electrical-power-relay-circuit-protection/analysis","conflicts":"/api/acts/ad-cessna-525-6-electrical-power-relay-circuit-protection/conflicts","importantCases":"/api/acts/ad-cessna-525-6-electrical-power-relay-circuit-protection/important-cases","documents":"/api/acts/ad-cessna-525-6-electrical-power-relay-circuit-protection/documents"}}