{"id":"F2006L01080","name":"AD/CESSNA 550/26 - Wing Fuel Boost Pumps","slug":"ad-cessna-550-26-wing-fuel-boost-pumps","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58413,"registerId":"commonwealth-F2006L01080-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 550/26 | Wing Fuel Boost Pumps | 6/2006 DM |\n| ---------------- | --------------------- | --------- |\n\n```html\n

Applicability:

Cessna Model S550, 550 and 551 model aeroplanes with serial numbers as follows:

Model

S550
550 and 551
550

Serial Number Range

0001 through 0160 inclusive
0002 through 0733 inclusive
0801 through 1075 inclusive

Requirement:

1. If not previously accomplished, revise the Limitations Section of the applicable Cessna aircraft flight manual (AFM) to prohibit use of the wing fuel boost pumps for defueling under certain conditions, by inserting the applicable temporary change identified in Cessna Service Bulletin SB550-28-14, dated 2 December 2003, or in the following table.

AFM Temporary Change

55BFM TC–R10–07
55BFM TC–R10–08
55BFM TC–R10–09
S55CA TC–04–01
S55CA TC–04–02
S55CA TC–04–03
S55FM TC–04–01
S55FM TC–04–02
S55FM TC–04–03

Dated

17 March 2004
17 March 2004
17 March 2004
8 July 2004
8 July 2004
8 July 2004
4 March 2004
4 March 2004
4 March 2004

AFM

Model 550 Citation Bravo
Model 550 Citation Bravo
Model 550 Citation Bravo
Model S550 Citation S/II
Model S550 Citation S/II
Model S550 Citation S/II
Model S550 Citation S/II
Model S550 Citation S/II
Model S550 Citation S/II

2. If not previously accomplished, install a placard close to the fuel quantity gauge, in accordance with the Accomplishment Instructions of the Cessna Service Bulletin SB550-28-08 dated 7 May 2004, SB550-28-14 dated 2 December 2003, or SB550-28-15 dated 20 January 2004, as applicable. In addition to the specifications in the service bulletin, the letters on the placard must be at least 6mm (1/4 inch) tall.

3. If not previously accomplished, carry out the following action in accordance with the Accomplishment Instructions of SB550-28-08, SB550-28-14, or
SB550-28-15, as applicable:

\n```\n\n| | a. Do a detailed inspection for chafed wiring of the wing fuel boost pumps. |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | b. Modify the wing fuel boost pumps. |\n| | Note 1: For the purposes of this Directive, a detailed inspection is: \"An intensive examination of a specific item, installation or assembly to detect damage, failure or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.'' |\n| | 4. If as a result of the Requirement 3.a. inspection and discrepancies are detected, accomplish all applicable corrective and other specified actions in accordance with the applicable service bulletin. |\n| | 5. Remove the Requirement 1 AFM temporary change and the Requirement 2 placard. |\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 2006-05-08, are considered acceptable for compliance with the equivalent Requirements of this Directive. |\n| | Note 2: FAA AD 2006-06-03 Amdt 39-14511 refers. |\n| Compliance: | For Requirements 1 and 2 - Within 25 hours time in service (TIS) after the effective date of this Directive. |\n| | For Requirement 3 - Within 300 flight TIS after the effective date of this Directive. |\n| | For Requirement 4 - Before further flight, immediately following the Requirement 3.a. inspection. |\n| | For Requirement 5 - Before further flight after the Requirement 3 inspection and modification are accomplished. |\n| | This Airworthiness Directive becomes effective on 20 April 2006. |\n| Background: | This Directive requires the revision of the AFM to initially prohibit use of the wing fuel boost pumps for defueling under certain conditions and the installation of a placard. The Directive subsequently requires the accomplishment of other specified investigative and corrective actions as necessary. Terminating action for this Directive is the modification of the wing boost pumps together with the removal of the AFM revision and placard. |\n\n| | The FAA has received a report of a chafed electrical wiring harness, which was arcing inside the fuel tank. This Directive is issued to prevent potential fuel vapour ignition in a fuel tank, which could result in explosion and loss of the aeroplane. |\n| --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n4 April 2006","sortOrder":0},{"sectionNumber":"AD/CESSNA 550/26","sectionType":"part","heading":"AD/CESSNA 550/26","content":"## AD/CESSNA 550/26","sortOrder":1},{"sectionNumber":"Wing Fuel Boost Pumps","sectionType":"part","heading":"Wing Fuel Boost Pumps","content":"## Wing Fuel Boost Pumps","sortOrder":2},{"sectionNumber":"6/2006 DM","sectionType":"part","heading":"6/2006 DM","content":"## 6/2006 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"},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"The directive moves beyond an initial, temporary operational restriction (AFM change and placard) to require mandatory physical inspection and modification of the wing fuel boost pumps as a terminating action. That expansion increases direct maintenance costs and compliance steps for owners/operators and introduces multiple service‑bulletin and AMOC coordination requirements."},"complexity_factors":["Multiple discrete compliance actions: AFM temporary change, placard installation, detailed inspection, modification, corrective actions and removal of temporary measures.","Different and short compliance timeframes (25 flight hours for AFM/placard; 300 flight hours for inspection; immediate action before further flight if discrepancies found).","Applicability limited to several model variants and specific serial number ranges, requiring aircraft-by-aircraft applicability checks.","References to multiple Cessna service bulletins (SB550-28-08, SB550-28-14, SB550-28-15) and allowance for FAA‑approved AMOCs, creating procedural coordination.","Technical inspection standard (detailed inspection) and wiring chafe detection require specialised maintenance skills, lighting and inspection aids.","Termination depends on successful modification, so compliance may involve staged operational restrictions and follow-up verification."],"plain_english_summary":"This Airworthiness Directive requires operators of specified Cessna 550/S550/551 aeroplanes to temporarily prohibit certain defueling operations using the wing fuel boost pumps, fit a placard and revise the aircraft flight manual, then carry out a detailed inspection for chafed wiring and modify the wing fuel boost pumps. Aircraft owners/operators must complete the placard and AFM change quickly, complete inspections within a set flying-time window and do corrective work; the measure is prompted by a reported wiring arcing inside a fuel tank to reduce the risk of fuel‑vapour ignition."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a clear, contained scope addressing a specific safety defect in specific aircraft. The multi-stage approach (initial operational restrictions followed by physical modifications) is typical for aviation safety directives and does not represent scope creep."},"complexity_factors":["Multiple serial number ranges across three aircraft models (S550, 550, 551) requiring careful cross-referencing","Nine different temporary change documents for different aircraft flight manual versions","Five distinct requirements with different compliance deadlines and dependencies","Reference to three different service bulletins (SB550-28-08, SB550-28-14, SB550-28-15) with specific dates","Conditional logic: Requirement 4 only triggers if discrepancies found in Requirement 3.a inspection","Terminating action (Requirement 5) depends on completion of Requirements 3 and 4","Acceptance of later FAA-approved revisions as Alternate Methods of Compliance (AMOC)","Specific technical requirement for placard letter height (6mm/1/4 inch) not in the referenced service bulletins"],"plain_english_summary":"This CASA Airworthiness Directive requires owners of certain Cessna 550 (Citation II/S/II/Bravo) jets to address a serious fuel‑tank fire risk from wing fuel boost pump wiring chafing. It mandates an immediate temporary flight‑manual change and warning placard, followed within set hours by detailed inspection and modification of the pump wiring, and repair of any damage before flight. The measures prevent potential ignition and catastrophic explosion."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-550-26-wing-fuel-boost-pumps","history":"/api/acts/ad-cessna-550-26-wing-fuel-boost-pumps/history","analysis":"/api/acts/ad-cessna-550-26-wing-fuel-boost-pumps/analysis","conflicts":"/api/acts/ad-cessna-550-26-wing-fuel-boost-pumps/conflicts","importantCases":"/api/acts/ad-cessna-550-26-wing-fuel-boost-pumps/important-cases","documents":"/api/acts/ad-cessna-550-26-wing-fuel-boost-pumps/documents"}}