{"id":"F2007L02129","name":"AD/CESSNA 550/25 Amdt 1 - Engine Fire Bottle Wiring","slug":"ad-cessna-550-25-amdt-1-engine-fire-bottle-wiring","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":67281,"registerId":"commonwealth-F2007L02129-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Cessna 550 (Citation II) Series Aeroplan","sectionType":"division","heading":"Cessna 550 (Citation II) Series Aeroplanes","content":"### Cessna 550 (Citation II) Series Aeroplanes\n\n| AD/CESSNA 550/25 Amdt 1 | Engine Fire Bottle Wiring | 8/2007 |\n| ----------------------- | ------------------------- | ------ |\n\n```html\n

Applicability:

Model 550, 551 and S550 aeroplanes as identified in the following Cessna Service Bulletins (SB):

Model

550
551
S550

SB

SB550-26-05
SB550-26-05
SBS550-26-02

Revision

Original
Original
Original

Date

1 April 2005
1 April 2005
1 April 2005

Requirement:

1. If not previously accomplished in accordance with the original issue of this Directive, install identification sleeves on the wires for the positive and negative terminal studs of the engine fire extinguishing bottles; re-connect the wires to the correct studs; test the connection and re-connect the wires again as applicable until the connection tests correctly. The above actions are to be accomplished in accordance with Cessna SB550-26-05 or SBS550-26-02 as applicable.

2. Fire extinguisher bottles may not be installed, as replacement spares, on any Cessna Model 550, 551 or S550 aeroplane unless identification sleeves have been installed on the wires for the positive and negative terminal studs in accordance with Requirement 1.

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 2007-11-17, are considered acceptable for compliance with the equivalent Requirements of this Directive.

Note: FAA AD 2007-11-17 Amdt 39-15074 refers.

Compliance:

For Requirement 1 - Within 100 hours time in service or 60 days after the effective date of this Amendment, whichever occurs first.

For Requirement 2 - As of the effective date of this Amendment.

This Amendment becomes effective on 2 August 2007.

\n```\n\n| Background: | The FAA has received reports of mis-wired fire extinguisher bottles, this could result in the circuit breaker disengaging (popping) when an attempt was made to discharge the bottles. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | The original issue of this Directive required the installation of identification sleeves on the wires for the positive and negative terminal studs of the engine fire extinguishing bottles together with re-connecting the wires to the correct terminal studs. These actions ensured that the fire extinguishing bottles may be activated in the event of an engine fire and that flammable fluids are not supplied during a fire, which could result in an unextinguished fire in the nacelle. |\n| | This Amendment continues the requirements of the original issue, extends the applicability to include Model 551 aeroplanes and includes a new requirement regarding replacement fire extinguisher bottles. |\n| | The original issue of this Directive became effective on 11 May 2006. |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n19 June 2007","sortOrder":0},{"sectionNumber":"AD/CESSNA 550/25 Amdt 1","sectionType":"part","heading":"AD/CESSNA 550/25 Amdt 1","content":"## AD/CESSNA 550/25 Amdt 1","sortOrder":1},{"sectionNumber":"Engine Fire Bottle Wiring","sectionType":"part","heading":"Engine Fire Bottle Wiring","content":"## Engine Fire Bottle Wiring","sortOrder":2},{"sectionNumber":"8/2007","sectionType":"part","heading":"8/2007","content":"## 8/2007","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This Amendment continues the original wiring/sleeve installation requirement and extends applicability to include Model 551 aeroplanes. It adds a new rule that replacement fire extinguisher bottles may not be installed on any affected aeroplane unless identification sleeves have been fitted, thereby widening both the covered fleet and the parts‑installation restrictions."},"complexity_factors":["Multiple aircraft models (550, 551, S550) and multiple Cessna Service Bulletins to follow","Retrofit work: physical installation of identification sleeves, iterative testing and re‑connection until correct","Operational restriction on replacement parts: replacement fire bottles cannot be installed unless sleeves are fitted","Compliance timeframe (100 flight hours or 60 days) creates scheduling/operational impact for operators","Acceptance of later SB revisions only if FAA approves them as an AMOC introduces regulatory dependency on FAA decisions"],"plain_english_summary":"Requires installation of identification sleeves on the positive and negative wires to engine fire‑extinguishing bottles, correct reconnection and testing; and prohibits fitting replacement bottles unless those sleeves are installed. It applies to Cessna Model 550, 551 and S550 aeroplanes.\n\nThe Directive is presented as ensuring bottles can be discharged and preventing supply of flammable fluids during an engine fire. Owners/operators pay for installation and testing and must comply within 100 flight hours or 60 days, following specified Cessna Service Bulletins or FAA‑approved later revisions."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"This Amendment 1 expanded the original directive's scope in two ways: (1) it extended applicability to include Model 551 aeroplanes (not covered in the original May 2006 issue), and (2) it added a new ongoing requirement restricting installation of replacement fire extinguisher bottles that lack the wiring identification sleeves. The original directive only addressed retrofitting existing aircraft."},"complexity_factors":["Single technical subject matter (wiring modification) with two distinct requirements","Cross-reference to three specific Cessna Service Bulletins for detailed implementation instructions","Conditional compliance timeline ('whichever occurs first' for Requirement 1)","Incorporation by reference of US FAA Airworthiness Directive (AD 2007-11-17) and Alternate Methods of Compliance (AMOCs)","Amendment structure requires understanding of what changed from original issue (expanded applicability to Model 551, added spare parts restriction)"],"plain_english_summary":"This AD orders owners/operators of certain Cessna Citation II/II‑SP/S/II jets to correct mis‑wired engine fire extinguisher bottles so the discharge circuit will work reliably. Affected aircraft must have wire‑polarity identified and corrected and replacements must be fitted only if sleeves are installed. It matters because incorrect wiring can trip the breaker and prevent fire bottle discharge, removing a critical means to extinguish an engine fire."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-550-25-amdt-1-engine-fire-bottle-wiring","history":"/api/acts/ad-cessna-550-25-amdt-1-engine-fire-bottle-wiring/history","analysis":"/api/acts/ad-cessna-550-25-amdt-1-engine-fire-bottle-wiring/analysis","conflicts":"/api/acts/ad-cessna-550-25-amdt-1-engine-fire-bottle-wiring/conflicts","importantCases":"/api/acts/ad-cessna-550-25-amdt-1-engine-fire-bottle-wiring/important-cases","documents":"/api/acts/ad-cessna-550-25-amdt-1-engine-fire-bottle-wiring/documents"}}