{"id":"F2006B07278","name":"AD/TB10/11 Amdt 1 - Fuselage Frame 9","slug":"ad-tb10-11-amdt-1-fuselage-frame-9","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49220,"registerId":"commonwealth-F2006B07278-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TB10/11 Amdt 1 - Fuselage Frame 9","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nAerospatiale (Socata) TB9 and TB10 (Tobago) Series Aeroplanes\n\nAD/TB10/11\n\nAmdt 1\n\n  \nFuselage Frame 9 6/88\n\nApplicability: TB9 and TB10 series aeroplanes with S/N 1 to 795 without modification No 70 embodied.\n\nRequirement: Action in accordance with Aerospatiale (Socata) Service Bulletin No 35/1.\n\nCompliance: (a) For aircraft with 1500 hours or more total time in service \\- inspect before further flight after 9 October 1987.\n\n    (b) For aircraft with less than 1475 hours total time in service \\- inspect within 25 hours time in service after 9 October 1987.\n\n    (c) Thereafter, reinspect at each issue of a new Maintenance Release.\n\nNote: Embodiment of Aerospatiale (Socata) modification No 70 constitutes terminating action for this Directive.\n\nBackground: Notification has been received from the manufacturer of in service cracking on overseas aircraft. This Directive has been amended to reflect the terminating action specified in the Requirement document.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The amendment explicitly records that embodying Aerospatiale (Socata) modification No 70 is terminating action for this Airworthiness Directive (Note). The Background states the directive has been amended to reflect the terminating action specified in the Requirement document (Background). Mechanically, the amendment therefore adds (or clarifies) an alternative compliance path — once Mod No 70 is embodied the recurring inspection requirements no longer apply (Note; Requirement)."},"complexity_factors":["Narrow technical scope limited to TB9/TB10 serial numbers 1–795 (Applicability) — reduces breadth but increases specificity.","Direct cross-reference to an external document (Aerospatiale (Socata) Service Bulletin No 35/1) for the exact inspection and corrective steps (Requirement) — requires access to and interpretation of that bulletin.","Multiple time-based compliance triggers tied to total hours-in-service with different deadlines (Compliance (a)-(b)) and a continuing duty at each Maintenance Release (Compliance (c)) — requires precise log-keeping.","Terminating action through embodiment of modification No 70 (Note) creates a clear but optional alternative compliance path that changes cost/timing incentives.","A small logical gap or discontinuity in the hour thresholds as printed (<1475 versus ≥1500) introduces ambiguity for aircraft between 1475 and 1499 hours, raising a minor interpretive complexity.","Practical implementation issues (parts, maintenance availability, interpretation of Service Bulletin) are external to the directive text but necessary to achieve compliance (Requirement; Compliance)."],"plain_english_summary":"What this directive does (mechanically)\n\n- It requires owners/operators of Aerospatiale (Socata) TB9 and TB10 (Tobago) series aeroplanes, serial numbers 1 to 795 that have not had modification No 70 embodied, to carry out the work set out in Aerospatiale (Socata) Service Bulletin No 35/1 (Requirement).\n- The directive sets deadlines for the first inspection depending on total time in service, and then requires recurring inspections at each issue of a new Maintenance Release (Compliance (a)-(c)).\n- If an aeroplane has 1500 hours or more total time in service, the inspection must be done before further flight after 9 October 1987 (Compliance (a)).\n- If an aeroplane has less than 1475 hours total time in service, the inspection must be done within 25 hours time in service after 9 October 1987 (Compliance (b)).\n- After the first inspection, the aeroplane must be reinspected at every new Maintenance Release (Compliance (c)).\n- Embodying Aerospatiale (Socata) modification No 70 removes the need to comply with this directive (Note).\n\nWhy the directive exists (as stated by the source)\n\n- The manufacturer notified the regulator about in-service cracking on overseas aircraft; this directive addresses that condition by prescribing inspections and referring to the manufacturer's Service Bulletin (Background, Requirement).\n\nWho pays, who decides, and what changes in behaviour\n\n- Who pays: aircraft owners/operators pay for the inspections and any corrective work ordered by the Service Bulletin (Requirement; Compliance).\n- Who decides: the Civil Aviation Safety Authority issued the directive and the manufacturer’s Service Bulletin specifies how to perform the inspection and corrective action (Requirement). The operator or maintenance organisation implements the Service Bulletin and decides whether to embody modification No 70 to stop recurring inspections (Requirement; Note).\n- What changes: operators must schedule and carry out immediate inspections for affected aeroplanes according to the hour thresholds, include reinspection at each Maintenance Release, and may choose to implement modification No 70 to avoid further inspections (Compliance (a)-(c); Note).\n\nCosts, incentives and trade-offs (mechanical assessment tied to the text)\n\n- Immediate compliance cost: owners of affected aeroplanes must get inspections done either before further flight (for those with ≥1500 hours) or within 25 hours of flight time (for those with <1475 hours) after the specified date, creating short-term workload and expense (Compliance (a)-(b)).\n- Ongoing cost vs one-off cost: continuing to operate without modification No 70 imposes recurring inspection work at each Maintenance Release (Compliance (c)); embodying modification No 70 is specified as terminating action, so an operator faces the trade-off of repeated inspection costs versus the one-off cost and downtime to carry out Mod No 70 (Note).\n- Compliance burden: operators must track total time-in-service thresholds and ensure inspections occur by the stated deadlines and at each Maintenance Release thereafter (Compliance (a)-(c)).\n- Implementation risk and practical constraints: the directive depends on the content and availability of the Service Bulletin actions (Requirement). Any delay in obtaining parts, instructions, or maintenance slots will affect an operator’s ability to meet the inspection deadlines (Requirement; Compliance).\n- Distribution of costs and benefits: the directive imposes inspection costs on every operator of the identified serial-numbered fleet that has not embodied Mod No 70; operators who embody Mod No 70 receive the direct benefit of no further inspections under this directive (Note).\n\nOther procedural notes from the text\n\n- The directive applies only to serial numbers 1–795 that have not had Modification No 70 embodied (Applicability; Note).\n- The directive was amended to reflect that the modification specified in the Requirement document is terminating action (Background; Note).\n\nSource citations: Applicability; Requirement (Aerospatiale (Socata) Service Bulletin No 35/1); Compliance (a)-(c); Note; Background."},"summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This amendment does not expand the population of affected aircraft; it only introduces modification No 70 as a terminating action that, if embodied, ends the ongoing inspection requirement. The original applicability and compliance timeframes remain as published in 1988."},"complexity_factors":["Clear applicability based on serial number range and modification status","Simple binary terminating action (modification embodied or not)","Repetitive inspection schedule linked to flight hours and Maintenance Release cycles","Single referenced Service Bulletin"],"plain_english_summary":"This is Amendment 1 to Airworthiness Directive AD/TB10/11, issued under Australia's Civil Aviation Regulations 1998, Part 39. It addresses cracking found in Fuselage Frame 9 on certain Socata TB9 and TB10 Tobago series aeroplanes. The original directive (June 1988) mandated inspections for cracks based on total time in service, with subsequent reinspections at each Maintenance Release. This amendment updates the directive by introducing a terminating action: installation of manufacturer modification No 70 (as detailed in Service Bulletin 35/1) permanently removes the need for those repetitive inspections. \n\nWho it affects: Owners and operators of TB9 and TB10 aircraft with serial numbers 1 to 795 that have not embodied modification No 70. \n\nWhat remains in force: For unmodified aircraft, the inspection schedule is unchanged. Aircraft with 1500 hours or more total time must be inspected before further flight after 9 October 1987. Those with less than 1475 hours must be inspected within 25 flight hours after that date. Thereafter, inspections were required at each issue of a new Maintenance Release. \n\nPractical point: If your aircraft already carries modification No 70, this directive no longer compels you to do the frame 9 checks. If the modification is not fitted, the recurring inspection obligation still stands unless you install the modification. This is a maintenance planning document, not a new emergency alert, and was published in 1988. It may still be relevant for vintage aircraft that have not been upgraded."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 1 to an existing Airworthiness Directive. The amendment is narrow and technical — it adds a terminating action (Modification No 70) that allows owners to permanently satisfy the inspection requirement. The scope remains tightly focused on the original safety issue (Fuselage Frame 9 cracking) and has not expanded beyond this specific structural inspection requirement."},"complexity_factors":["Very short document (under 300 words)","Only 4 defined elements: specific aircraft models, serial number range, modification number, and flight hour thresholds","Simple conditional logic: two compliance paths based on flight hours, plus one terminating condition","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Single technical reference to manufacturer Service Bulletin No 35/1","Clear, unambiguous compliance dates and actions"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific inspections or repairs on certain aircraft.\n\n**What it does:**\n- Requires owners/operators of specific Socata TB9 and TB10 (Tobago) light aircraft to inspect **Fuselage Frame 9** (a structural part of the aircraft body) for cracks.\n\n**Who it affects:**\n- Owners and operators of TB9 and TB10 series aeroplanes with **serial numbers 1 to 795** that have **not** had a specific factory modification (Modification No 70) installed.\n\n**What must be done:**\n- **High-time aircraft** (1,500+ flight hours): Inspect immediately before next flight after 9 October 1987.\n- **Lower-time aircraft** (under 1,475 flight hours): Inspect within 25 flight hours after 9 October 1987.\n- **Ongoing:** Re-inspect every time the aircraft gets a new **Maintenance Release** (an official document certifying an aircraft is safe to fly, typically issued after periodic maintenance checks).\n\n**How to fix it permanently:**\n- Installing **Modification No 70** (a factory-approved design change) permanently satisfies this requirement — no more inspections needed.\n\n**Why it matters:**\n- Cracks in Fuselage Frame 9 could compromise the aircraft's structural integrity and safety. The directive was issued after the manufacturer reported cracking on similar aircraft overseas."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb10-11-amdt-1-fuselage-frame-9","history":"/api/acts/ad-tb10-11-amdt-1-fuselage-frame-9/history","analysis":"/api/acts/ad-tb10-11-amdt-1-fuselage-frame-9/analysis","conflicts":"/api/acts/ad-tb10-11-amdt-1-fuselage-frame-9/conflicts","importantCases":"/api/acts/ad-tb10-11-amdt-1-fuselage-frame-9/important-cases","documents":"/api/acts/ad-tb10-11-amdt-1-fuselage-frame-9/documents"}}