{"id":"F2006B02932","name":"AD/B737/27 Amdt 1 - TE Flap Track Support Fitting Attach Bolts","slug":"ad-b737-27-amdt-1-te-flap-track-support-fitting-attach-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42274,"registerId":"commonwealth-F2006B02932-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/27 Amdt 1 - TE Flap Track Support Fitting Attach Bolts","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Boeing 737 Series Aeroplanes\n\n \n\nAD/B737/27\n\nAmdt 1\n\n\nTE Flap Track Support Fitting Attach Bolts 8/91\n\n \n\nApplicability: Model 737-300 and -400 series as listed in Boeing ASB 737-57A1202 Revision 1.\n\n \n\nRequirement: Action in accordance with the Technical Requirements of FAA AD 91-09-17 Amdt 39-6984.\n\n \n\nCompliance: As specified in the Requirement Document with a revised effective date of 8 August 1991 for Australian registered aircraft.\n\n \n\nBackground: Incorrect material bolts and nuts may have been used to attach the outboard flap inboard track support fitting.\n\n \n\nAmendment 1 is prompted by information from the manufacturer which indicated that additional aircraft were not inspected for the proper nuts before they left the factory.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a narrow, technical amendment to an existing Airworthiness Directive. Amendment 1 simply expands the applicability to cover additional aircraft that were discovered to have the same manufacturing defect. The scope remains tightly focused on the specific bolt/nut inspection issue for Boeing 737-300/-400 flap track fittings."},"complexity_factors":["Very short document (approximately 200 words)","Only 4 substantive sections: Applicability, Requirement, Compliance, and Background","Minimal defined terms (only standard aviation abbreviations like 'TE' for trailing edge)","Single cross-reference to external FAA document for technical details","No nested conditions or exceptions — straightforward mandatory compliance","Clear, unambiguous language with no conditional logic"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or inspections on certain aircraft.\n\n**What it does:** It orders owners and operators of specific Boeing 737-300 and 737-400 aircraft to check and fix a problem with bolts and nuts that attach the **trailing edge (TE) flap track support fitting** — a structural component that helps control the flaps on the wings.\n\n**The problem:** Some aircraft may have been built with **incorrect bolts or nuts** (wrong material specification) attaching the outboard flap's inboard track support. This is a safety issue because if these fasteners fail, it could affect the aircraft's ability to control its flaps during takeoff and landing.\n\n**Who must act:** Anyone operating a Boeing 737-300 or -400 series aircraft in Australia that is listed in Boeing's Alert Service Bulletin 737-57A1202 Revision 1.\n\n**What they must do:** Follow the technical instructions in the corresponding US Federal Aviation Administration (FAA) directive (AD 91-09-17), but with an Australian compliance deadline of **8 August 1991**.\n\n**Why Amendment 1 matters:** The original directive missed some aircraft. This update adds more planes to the list because the manufacturer discovered additional aircraft left the factory without being checked for the correct nuts."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Yes. Amendment 1 broadened the practical scope by extending inspection obligations to additional aircraft identified by the manufacturer as not having been inspected before leaving the factory; the AD adopts FAA AD 91-09-17 and sets an Australian effective date (Compliance; Amendment 1; Background)."},"complexity_factors":["Cross-reference to an external FAA document (Requirement: Action in accordance with FAA AD 91-09-17 Amdt 39-6984) — compliance depends on a foreign AD's technical requirements.","Dependence on a manufacturer service bulletin listing (Applicability: Model 737-300 and -400 series as listed in Boeing ASB 737-57A1202 Revision 1) — applicability requires consulting that ASB.","Technical inspection and parts issue (Background: incorrect material bolts and nuts used to attach the outboard flap inboard track support fitting) — requires technical maintenance work and parts verification.","Specified compliance timing (Compliance: as specified in the Requirement Document with revised effective date of 8 August 1991) — a fixed effective date creates scheduling and operational constraints.","Amendment based on new factory information (Amendment 1 prompted by manufacturer information that additional aircraft were not inspected) — expands the population potentially requiring action."],"plain_english_summary":"Adopts FAA Airworthiness Directive 91-09-17 for Boeing 737-300/-400 aeroplanes, requiring inspection and correction of incorrect bolts and nuts that attach the outboard flap inboard track support fitting. It applies to Australian-registered aircraft listed in Boeing ASB 737-57A1202 Revision 1, with compliance as specified in the FAA AD and an Australian effective date of 8 August 1991.\n\nOperators pay for inspections and any corrective work. CASA enforces the directive; Amendment 1 extends the inspection requirement after the manufacturer reported additional aircraft left the factory uninspected."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-27-amdt-1-te-flap-track-support-fitting-attach-bolts","history":"/api/acts/ad-b737-27-amdt-1-te-flap-track-support-fitting-attach-bolts/history","analysis":"/api/acts/ad-b737-27-amdt-1-te-flap-track-support-fitting-attach-bolts/analysis","conflicts":"/api/acts/ad-b737-27-amdt-1-te-flap-track-support-fitting-attach-bolts/conflicts","importantCases":"/api/acts/ad-b737-27-amdt-1-te-flap-track-support-fitting-attach-bolts/important-cases","documents":"/api/acts/ad-b737-27-amdt-1-te-flap-track-support-fitting-attach-bolts/documents"}}