{"id":"F2006B03215","name":"AD/B747/33 Amdt 2 - Wing Trailing Edge Flap Tracks","slug":"ad-b747-33-amdt-2-wing-trailing-edge-flap-tracks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42587,"registerId":"commonwealth-F2006B03215-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/33 Amdt 2 - Wing Trailing Edge Flap Tracks","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 747 Series Aeroplanes\n\n \n\nAD/B747/33\n\nAmdt 2\n\n\nWing Trailing Edge Flap Tracks 8/90\n\n \n\nApplicability: Model B747 line numbers 1 through 584 except B747SP. Requirement:  Action in accordance with Boeing SB747-57A2225 Rev. 4.\n\nNote: FAA AD 83-21-02 refers.\n\n \n\nCompliance: As detailed in the Requirement Document.\n\n \n\nBackground:  Water accumulation in the track aft cavity has resulted in corrosion and consequent aft web cracking. Amendment 1 references the latest revision of the Requirement document, which adds terminating action. Amendment 2 clarifies aircraft affected.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive has remained tightly focused on its original purpose: addressing corrosion in wing flap tracks on specific Boeing 747 models. The amendments have been technical clarifications (which aircraft are covered) and procedural improvements (adding terminating action), not scope expansion."},"complexity_factors":["Extremely short document (under 200 words)","Only 2 defined applicability criteria (line numbers 1-584, excluding B747SP)","Single cross-reference to Boeing Service Bulletin and FAA AD 83-21-02","No conditional logic or nested exceptions — straightforward mandatory action","No interpretation section or defined terms","Simple amendment history (3 versions tracking clarification and terminating action)"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific maintenance actions on certain aircraft.\n\n**What it does:** It orders owners and operators of specific Boeing 747 aeroplanes to inspect and repair the **wing trailing edge flap tracks** — the mechanical rails that guide the flaps (the large movable surfaces on the back of the wings that help with lift during takeoff and landing).\n\n**The problem:** Water was collecting in a cavity behind these tracks, causing **corrosion** (rust) and **cracking** in the metal web structure. This could weaken the wing and create a serious flight safety risk.\n\n**Who must act:** Anyone operating Boeing 747 aircraft with **line numbers 1 through 584**, **except** the B747SP variant (a shorter, special performance model). This covers most early to mid-production 747s.\n\n**What they must do:** Follow the instructions in **Boeing Service Bulletin 747-57A2225 Revision 4** — a technical document from the manufacturer detailing inspection and repair procedures. The latest version of this directive (Amendment 2) clarifies exactly which aircraft are affected, and Amendment 1 added a \"terminating action\" — meaning there's now a permanent fix available rather than just repeated inspections.\n\n**Why it matters:** Corrosion in wing structures can lead to structural failure. This directive prevents potential accidents by ensuring damaged components are found and fixed before they become dangerous."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The AD's scope was altered through its amendments. Amendment 1 changed the required technical action by referencing a revision of the Boeing service bulletin that adds a terminating action (affecting the nature and possibly the duration of repeat work). Amendment 2 clarified which aircraft are included (line numbers 1–584, excluding the B747SP), narrowing or specifying the population of affected aircraft (see \"Background\" and \"Applicability\")."},"complexity_factors":["Reference to an external technical document (Boeing SB747-57A2225 Rev. 4) — requires obtaining and following another document to know exact procedures and timing (\"Requirement\").","Applicability rules with an exception (line numbers 1–584 except B747SP) — requires checking each aircraft's line number to determine whether the AD applies (\"Applicability\").","Amendments change the AD content: Amendment 1 adds a terminating action and Amendment 2 clarifies affected aircraft, so compliance obligations depend on the AD version in force (\"Background\").","The AD text does not include specific compliance intervals or technical steps; those are deferred to the Requirement Document, creating implementation dependence (\"Compliance\").","Cross-reference to a foreign regulator's AD (FAA AD 83-21-02) might require coordinated compliance for operators subject to multiple jurisdictions (\"Note\")."],"plain_english_summary":"This AD mandates compliance with Boeing Service Bulletin SB747-57A2225 Rev.4 for Boeing 747s (line numbers 1–584, excluding the B747SP) to detect and fix corrosion and cracking in wing trailing‑edge flap track aft webs. Issued by CASA to eliminate a water‑ingress driven structural risk, it makes inspections/modifications mandatory and places cost and implementation responsibility on operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-33-amdt-2-wing-trailing-edge-flap-tracks","history":"/api/acts/ad-b747-33-amdt-2-wing-trailing-edge-flap-tracks/history","analysis":"/api/acts/ad-b747-33-amdt-2-wing-trailing-edge-flap-tracks/analysis","conflicts":"/api/acts/ad-b747-33-amdt-2-wing-trailing-edge-flap-tracks/conflicts","importantCases":"/api/acts/ad-b747-33-amdt-2-wing-trailing-edge-flap-tracks/important-cases","documents":"/api/acts/ad-b747-33-amdt-2-wing-trailing-edge-flap-tracks/documents"}}