{"id":"F2005L03582","name":"AD/CESSNA 400/113 - Avionics Bus Circuit Breaker Switch","slug":"ad-cessna-400-113-avionics-bus-circuit-breaker-switch","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":39174,"registerId":"commonwealth-F2005L03582-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Cessna 400 Series Aeroplanes","sectionType":"division","heading":"Cessna 400 Series Aeroplanes","content":"### Cessna 400 Series Aeroplanes\n\n| AD/CESSNA 400/113 | Avionics Bus Circuit Breaker Switch | 13/2005 |\n| ----------------- | ----------------------------------- | ------- |\n\n```html\n

Applicability:

Cessna Model 400 aeroplanes as follows equipped with an avionics bus circuit breaker switch, part number (P/N) CM3589-50, 593-250-101, 593-250-102,
W31-X2M5A-50 or W31-X1000-50:

Model

Serial Numbers

401

655 and 401-0001 through 401-0322

401A

655 and 401A0001 through 401A0132

401B

401B0001 through 401B0221

402

402-0001 through 402-0322

402A

402A0001 through 402A0129

402B

402B0001 through 402B0122, 402B0201 through 402B0249, 402B0301 through 402B0455, 402B0501 through 402B0640, 402B0801 through 402B0935, 402B1001 through 402B1100, 402B1201 through 402B1250 and 402B1301 through 402B1384

402C

689, 402C0001 through 402C0125, 402C0201 through 402C0355, 402C0401 through 402C0528, 402C0601 through 402C0653, 402C0801 through 402C0807 and 402C0808 through 402C1020

404

682, 404-0001 through 404-0136, 404-0201 through 404-0246,
404-0401 through 404-0460, 404-0601 through 404-0695 and
404-0801 through 404-0859

411

642 and 411-0001 through 411-0250

411A

411-0251 through 411-0300

414

667, 414-0001 through 414-0099, 414-0151 through 414-0175,
414-0251 through 414-0280, 414-0351 through 414-0437,
414-0451 through 414-0550, 414-0601 through 414-0655,
414-0801 through 414-0855 and 414-0901 through 414-0965

\n```\n\n```html\n

414A

414A0001 through 414A0121, 414A0201 through 414A0340, 414A0401 through 414A0535, 414A0601 through 414A0680, 414A0801 through 414A0858 and 414A1001 through 414A1212

421

693 and 421-0001 through 421-0200

421A

421A0001 through 421A0158

421B

421B0001 through 421B0056, 421B0101 through 421B0147, 421B0201 through 421B0275, 421B0301 through 421B0486, 421B0501 through 421B0665 and 421B0801 through 421B0970

421C

421C0001 through 421C0171, 421C0201 through 421C0350, 421C0401 through 421C0525, 421C0601 through 421C0715, 421C0801 through 421C0910, 421C1001 through 421C1115, 421C1201 through 421C1257, 421C1401 through 421C1413 and 421C1801 through 421C1807

425

425-0001 through 425-0236

441

698 and 441-0001 through 441-0362

Requirement:

1. Inspect the avionics bus circuit breaker switch to determine the P/N and date code in accordance with the following:

a. For Models 425 and 441 aeroplanes - Cessna Conquest Service Bulletin (SB) CQB05-2, dated 21 February 2005 and the applicable maintenance manual.

b. For all other affected aeroplane models - Cessna Multi-engine SB MEB05-1 dated21 February 2005 and the applicable maintenance manual.

If the P/N is CM3589-50, 593-250-101, 593-250-102, W31-X2M5A-50 or
W31-X1000-50 and the date code is 0434 or later; then no further action is required.

2. If the P/N is CM3589-50, 593-250-101, 593-250-102, W31-X2M5A-50 or
W31-X1000-50 and there is no date code, replace the avionics bus circuit breaker switch with a P/N CM3589-50 that has a date code of 0434 or later in accordance with the following:

a. For Models 425 and 441 aeroplanes - SB CQB05-2, dated 21 February 2005 and the applicable maintenance manual.

b. For all other affected aeroplane models - SB MEB05-1 dated21 February 2005 and the applicable maintenance manual.

\n```\n\n| | 3. If the P/N is CM3589-50, 593-250-101, 593-250-102, W31-X2M5A-50 orW31-X1000-50 and the date code is earlier than 0434, the part has a safe life limit of 1,000 hours time in service (TIS) and must be replaced within the 1,000 hour time limit with a P/N CM3589-50 that has a date code of 0434 or later in accordance with the following: |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | a. For Models 425 and 441 aeroplanes - SB CQB05-2, dated 21 February 2005 and the applicable maintenance manual. |\n| | b. For all other affected aeroplane models - SB MEB05-1 dated21 February 2005 and the applicable maintenance manual. |\n| | 4. Avionics bus circuit breaker switches P/N CM3589-50, 593-250-101,593-250-102, W31-X2M5A-50 or W31-X1000-50 that do not have a date code or have a date code earlier than 0434 may not be installed as a replacement spare. |\n| | Later revisions of the above SB(s), approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2005-20-25, are considered acceptable for compliance with the equivalent Requirements of this Directive. |\n| | Note: FAA AD 2005-20-25 Amdt 39-14321 refers. |\n| Compliance: | For Requirement 1 - Within the next 200 hours TIS, the next 12 months or at the next scheduled inspection, after the effective date of this Directive, whichever occurs first. |\n| | For Requirement 2 - Before further flight after the Requirement 1 inspection. |\n| | For Requirement 3 - Within the 1,000-hour TIS safe life limit. |\n| | For Requirement 4 - As of the effective date of this Directive. |\n| | This Airworthiness Directive becomes effective on 22 December 2005. |\n| Background: | The FAA has received failure reports of certain Tyco Electronics circuit breaker switches installed on the master avionics bus of Cessna Model 400 aeroplanes. |\n| | Analysis of the circuit breaker switch revealed the copper braid inside the switch had frayed. Continued use causes an internal short. The internal short could result in the internal switch components or external wiring melting because it is no longer protected by the circuit breaker. The affected circuit breaker switches have a date code earlier than 0434 or do not have a date code on them. The date code consists of four digits, the first two represent the year and the last two represent the week of the year the part was made. |\n\n| | Failure of these circuit breaker switches causes smoke and a burning smell in the cockpit. If not prevented failure could lead to reduced ability to control the aeroplane. This Directive requires the inspection of the circuit breaker switches and, if necessary, their replacement. |\n| --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n10 November 2005","sortOrder":0},{"sectionNumber":"AD/CESSNA 400/113","sectionType":"part","heading":"AD/CESSNA 400/113","content":"## AD/CESSNA 400/113","sortOrder":1},{"sectionNumber":"Avionics Bus Circuit Breaker Switch","sectionType":"part","heading":"Avionics Bus Circuit Breaker Switch","content":"## Avionics Bus Circuit Breaker Switch","sortOrder":2},{"sectionNumber":"13/2005","sectionType":"part","heading":"13/2005","content":"## 13/2005","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":6,"scope_assessment":{"changed":false,"description":"The Directive implements the FAA AD referenced (FAA AD 2005-20-25) by requiring inspection, conditional replacement, a 1,000‑hour safe life for older parts, and banning non‑compliant spares. It does not expand the set of affected part numbers or aircraft beyond the Directive's applicability table, and allows later FAA‑approved Service Bulletin revisions as acceptable alternate methods of compliance. Compliance timings and actions mirror the Directive text and its cited Service Bulletins."},"complexity_factors":["Long list of affected aircraft models and many discrete serial number ranges, increasing tracking burden for operators.","Multiple affected part numbers (CM3589-50, 593-250-101, 593-250-102, W31-X2M5A-50, W31-X1000-50) and a date‑code condition (0434 cutoff) that create conditional compliance paths.","Different compliance actions depending on inspection result: no action, immediate replacement if no date code, or a 1,000‑hour safe‑life and later replacement if date code earlier than 0434.","Staggered compliance deadlines (within 200 hours TIS/12 months/next inspection; before further flight; within 1,000 hours TIS) raising scheduling complexity.","Dependence on manufacturer Service Bulletins (SB CQB05-2 and SB MEB05-1) and applicable maintenance manuals to carry out inspections and replacements.","Prohibition on installing non‑compliant spares imposes supply/parts management and procurement constraints.","Acceptance of later FAA‑approved SB revisions as Alternate Methods of Compliance (AMOC) introduces external regulatory dependence."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of specified Cessna Model 400-series aeroplanes with certain avionics-bus circuit breaker part numbers to inspect each switch for part number and a four‑digit date code, replace units with no date code or with a date code earlier than 0434, and impose a 1,000‑hour safe‑life on earlier parts. Inspections and replacements have staged deadlines (inspection within 200 hours TIS/12 months/next inspection; replacements before further flight or within 1,000 hours); non‑compliant spares are banned. The stated purpose is to address internal braid fraying that can cause shorts, smoke and loss of control."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a focused, single-purpose scope: addressing a specific defective part on specific aircraft models. The detailed applicability table and conditional requirements are typical for aviation safety directives and do not represent scope creep beyond the original safety purpose."},"complexity_factors":["Extensive applicability table covering 18 aircraft models with complex serial number ranges (some with multiple non-consecutive ranges)","Multiple conditional branches based on part number and date code combinations","Different technical reference documents required for different aircraft models (Service Bulletin CQB05-2 vs MEB05-1)","Four separate compliance deadlines with 'whichever occurs first' logic","Cross-reference to FAA AD 2005-20-25 and AMOC provisions for alternative compliance methods","Technical terminology requiring aviation maintenance knowledge (TIS = Time In Service, P/N = Part Number, SB = Service Bulletin)"],"plain_english_summary":"This AD requires owners/operators of many Cessna 400-series aircraft to inspect—and, in many cases, replace—the avionics bus circuit breaker switch because certain switches can fail internally, causing smoke, melting, and loss of avionics protection that could impair control. Inspections have near-term deadlines and switches without a date code or made before 2004 must be removed from service; affected aircraft and prohibited replacement parts are identified by specific switch part numbers."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-113-avionics-bus-circuit-breaker-switch","history":"/api/acts/ad-cessna-400-113-avionics-bus-circuit-breaker-switch/history","analysis":"/api/acts/ad-cessna-400-113-avionics-bus-circuit-breaker-switch/analysis","conflicts":"/api/acts/ad-cessna-400-113-avionics-bus-circuit-breaker-switch/conflicts","importantCases":"/api/acts/ad-cessna-400-113-avionics-bus-circuit-breaker-switch/important-cases","documents":"/api/acts/ad-cessna-400-113-avionics-bus-circuit-breaker-switch/documents"}}