{"id":"F2008L00874","name":"AD/B747/374 - Korry Pushbutton Switches","slug":"ad-b747-374-korry-pushbutton-switches","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":72993,"registerId":"commonwealth-F2008L00874-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 747 Series Aeroplanes","sectionType":"division","heading":"Boeing 747 Series Aeroplanes","content":"### Boeing 747 Series Aeroplanes\n\n| AD/B747/374 | Korry Pushbutton Switches | 4/2008 |\n| ----------- | ------------------------- | ------ |\n\n| Applicability: | Model 747-400, -400D and -400F series aeroplanes as identified in Boeing Alert Service Bulletin (ASB) 747-33A2280, Revision 1, dated 25 September 2003. |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Either: |\n| | a. Carry out a general visual inspection of the switches identified for the panel assemblies specified in ASB 747-33A2280, Revision 1 to identify configuration `D' master modules and the part number (P/N) of the switch; or |\n| | b. Inspect the panel assemblies identified in ASB 747-33A2280, Revision 1 to determine the part number (P/N). If the P/N is identified as a new P/N in Appendix B of the service bulletin, no further action is required. |\n| | Note 1: For the purposes of this Directive, a general visual inspection is \"A visual examination of a interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normal available lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked.'' |\n| | Note 2: ASB 747-33A2280, Revision 1 refers to Korry Service Bulletin (SB)433-33-05, dated 23 July 2001, as an additional source of service information for finding configuration `D' switches, for replacing the switch master module with a configuration `D' master module, and for doing various operational tests after the replacement. |\n| | 2. If, as a result of the Requirement 1.b. inspection, the P/N is not identified as a new P/N, the inspection required by Requirement 1.a. must be accomplished. |\n| | 3. If, during any Requirement 1.a. inspection, any switch is found that does not have a configuration `D' switch master module and the switch P/N is not specified Table 1, carry out either of the following and do the part number revision in accordance with Requirement 3.c: |\n\n| | a. Replace the switch with a switch specified in Table 1, in accordance with ASB 747-33A2280, Revision 1, except as provided by Requirement 4. |\n| --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | b. Replace the switch master module with a new configuration `D' master module in accordance with ASB 747-33A2280, Revision 1. |\n| | c. If all switches on a panel assembly have a configuration `D' master module or have a switch P/N specified Table 1 revise the P/N of the panel assembly in accordance with ASB 747-33A2280, Revision 1. |\n| | Table 1 |\n| | Boeing P/N S231T290-4201 through -4325 inclusive,Korry P/N 4336731004-4201 through -4325 inclusive, orswitches that have a configuration `D' master module. |\n| | Note 3: One-to-one switch correlation between the existing switches and the new part number switches can be found in Korry SB 433-33-06, dated 7 November 2001. |\n| | 4. If, during any Requirement 1.a. inspection, a configuration `D' switch master module is found or the P/N is specified in Table 1 on all switches for a panel assembly, revise the part number of the panel assembly, in accordance with ASB 747-33A2280, Revision 1. |\n| | 5. If any panel assemblies, switches or master modules are replaced during any action required by this Directive, carry out all applicable operational tests in accordance with ASB 747-33A2280, Revision 1, except as provided by Requirement 6. |\n| | 6. Where paragraph 3.B.14.b.(3) of the Accomplishment Instructions of ASB747-33A2280, Revision 1 specifies procedures to do a test of the engine ignition control/fuel jettison module assembly, this Directive requires that operatorsdry-motor the engine to remove the fuel from the tailpipe before doing the procedures in paragraph 3.B.14.b.(3). All fuel must be removed from the engine tailpipe before performing the test, because during the test the engine igniter will be energized. |\n| | Note 4: ASB 747-33A2280, Revision 1 refers to the Boeing component service bulletins specified in Table 2 of this Directive as additional sources of service information for replacing the switch or switch master module at critical locations, for doing operational tests after the replacement, and for identifying new panel part numbers. |\n\n```html\n

Table 2

Boeing Component Service Bulletin

Date

Critical Location

233U3201-30-04, Revision 1

25 September 2003

Rain Removal/Anti-ice Module

233U3202-24-02, Revision 1

25 September 2003

Electrical and Standby Power/Auxiliary Power Unit Start Module

233U3203-36-01, Revision 1

25 September 2003

Bleed Air Control Module

233U3206-28-01, Revision 1

25 September 2003

Engine Ignition Control/Fuel Jettison Module

233U3208-22-02, Revision 1

25 September 2003

Passenger Oxygen and Yaw Damper Module

233U3214-26-06, Revision 1

25 September 2003

Fire Control Module

257U0002-32-04, including Appendix A

19 December 2001

Landing Gear Actuator Control Lever Module Assembly

Actions accomplished before the effective date of this Directive in accordance with Boeing ASB 747-33A2280 dated 19 December 2001, are considered acceptable for compliance with the corresponding action specified in this Directive, provided that the actions specified in this Directive are done on the switches for the additional panel assemblies specified in Revision 1 of the service bulletin.

Later revisions of the above Boeing SBs, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-02-14, are considered acceptable for compliance with the equivalent Requirements of this Directive.

Note 5: FAA AD 2008-02-14 Amdt 39-15344 refers.

Compliance:

For Requirements 1 and 2 - Within 60 months after the effective date of this Directive.

For Requirement 3, 4 and 5 - Before further flight after the Requirement 1.a. inspection.

\n```\n\n| | For Requirement 6 - Before carrying out a test of the engine ignition control/fuel jettison module assembly in accordance with Requirement 5. |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | This Airworthiness Directive becomes effective on 10 April 2008. |\n| Background: | The FAA has received a report indicating that the integrated drive generator failed in flight due to a possible switch malfunction. This Directive is issued to ensure that certain lighted pushbutton switches in the flight compartment do not malfunction and cause the flightcrew to be unable to control critical systems and continue safe operation of the aeroplane. |\n| | The Directive requires an inspection of certain lighted pushbutton switches in the flight compartment for configuration `D' master modules and part numbers together with any necessary corrective action. The Directive also provides an option to inspect panel assemblies for part numbers. |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n26 February 2008","sortOrder":0},{"sectionNumber":"AD/B747/374","sectionType":"part","heading":"AD/B747/374","content":"## AD/B747/374","sortOrder":1},{"sectionNumber":"Korry Pushbutton Switches","sectionType":"part","heading":"Korry Pushbutton Switches","content":"## Korry Pushbutton Switches","sortOrder":2},{"sectionNumber":"4/2008","sectionType":"part","heading":"4/2008","content":"## 4/2008","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"Revision 1 of Boeing ASB expanded the set of affected panel assemblies; the Directive accepts actions done to the earlier ASB dated 19 December 2001 only if those actions are applied to the additional panels specified in Revision 1. Later Boeing SB revisions approved by the FAA as AMOCs are also acceptable, effectively widening procedural compliance options compared with the original ASB."},"complexity_factors":["Multiple compliance pathways: visual inspection of switches or inspection by panel assembly part number, with conditional follow-up actions.","Cross-references to external service documents (Boeing ASB 747-33A2280 Rev 1 and Korry service bulletins) for procedures and part correlations.","Parts identification complexity: Table 1 lists inclusive P/N ranges and configuration criteria requiring part-number revisions when satisfied.","Mixed timing obligations: a long window for initial inspections (within 60 months) but immediate (before further flight) requirement for corrective replacements and tests.","Operational-test safety constraint: engine ignition/fuel‑jettison module tests must be preceded by dry‑motoring to remove fuel, adding procedural and safety steps.","Acceptance of prior work and later SB revisions as AMOCs creates record‑review and equivalence-assessment burden for operators and maintenance organisations.","Applicability limited to specific 747 models and specified panel assemblies, requiring fleet-level traceability of installed panels and switches."],"plain_english_summary":"This Airworthiness Directive requires operators of Boeing 747-400, -400D and -400F aeroplanes to inspect specified cockpit Korry lighted pushbutton switches or panel part numbers, replace non-compliant switches or switch master modules with a configuration 'D' or approved part number, and run operational tests to prevent switch malfunctions that could impair control of critical systems.\n\nAirlines pay for inspections, replacements and tests; the regulator (CASA via the Directive) sets deadlines (inspections within 60 months; required repairs before next flight) and accepts FAA‑approved alternate compliance. Engine ignition tests must be preceded by dry‑motoring to remove fuel."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a focused, single-purpose scope: addressing a specific safety defect in Korry pushbutton switches on Boeing 747-400 series aircraft. The directive does not appear to have expanded beyond its original safety intent. The various requirements, tables, and references to service bulletins all serve the core purpose of identifying and rectifying potentially faulty switches. The inclusion of specific test modifications (Requirement 6) and recognition of prior compliance are typical of AD drafting practice rather than scope creep."},"complexity_factors":["Multiple nested conditional requirements (Requirements 1-6 with cross-dependencies — e.g., Requirement 2 triggers Requirement 1.a if 1.b fails, Requirement 3 has sub-requirements a/b/c)","Heavy reliance on external technical documents — operators must consult Boeing Alert Service Bulletin 747-33A2280 Revision 1, Korry Service Bulletin 433-33-05, and multiple Boeing Component Service Bulletins listed in Table 2","Technical terminology requiring specialized aviation knowledge (e.g., \"configuration D master module,\" \"dry-motor,\" \"integrated drive generator,\" \"part number revision\")","Dual-path compliance options (visual inspection vs. part number check) with different consequences depending on findings","Specific exception in Requirement 6 that modifies standard test procedures from the referenced service bulletin","Grandfathering clause for actions taken under earlier service bulletin revision (December 2001) with additional conditions","Recognition of FAA Alternate Methods of Compliance (AMOCs) as acceptable for Australian compliance","Table-based reference system (Table 1 for acceptable part numbers, Table 2 for critical locations and associated service bulletins)"],"plain_english_summary":"CASA’s AD mandates inspections and, if necessary, replacement or module upgrade of cockpit pushbutton switches on Boeing 747-400, 747-400D and 747-400F aircraft. Operators must inspect panels or part numbers, update records, and perform operational tests (with specified safety steps) after any change.\n\nThe rule — inspections within 60 months and repairs/tests before next flight — addresses switch failures that could disable critical systems (engines, fire suppression, fuel jettison, oxygen), preventing possible catastrophic loss of function."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-374-korry-pushbutton-switches","history":"/api/acts/ad-b747-374-korry-pushbutton-switches/history","analysis":"/api/acts/ad-b747-374-korry-pushbutton-switches/analysis","conflicts":"/api/acts/ad-b747-374-korry-pushbutton-switches/conflicts","importantCases":"/api/acts/ad-b747-374-korry-pushbutton-switches/important-cases","documents":"/api/acts/ad-b747-374-korry-pushbutton-switches/documents"}}