{"id":"F2009L02967","name":"AD/EXTRA/10 - Fuselage Structure - Tail Spring Support","slug":"ad-extra-10-fuselage-structure-tail-spring-support","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":80466,"registerId":"commonwealth-F2009L02967-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Extra EA-300 Series Aeroplanes","sectionType":"division","heading":"Extra EA-300 Series Aeroplanes","content":"### Extra EA-300 Series Aeroplanes\n\n| AD/EXTRA/10 | Fuselage Structure - Tail Spring Support | 10/2009 DM |\n| ----------- | ---------------------------------------- | ---------- |\n\n| Applicability: | Model EA 300/L aircraft, serial numbers 01 through 170, 172, 173, 1171 and 1174 through 1299.Model EA 300/200 aircraft, serial numbers 01 through 31 and 1032 through 1043.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Inspect the tail spring support in accordance with PART I of EXTRA Service Bulletin No. SB-300-2-97 Issue B, or later EASA approved revision.2. If a crack is detected during any inspection, modify the tail spring support structure as instructed in PART II of EXTRA Service Bulletin No. SB-300-2-97 Issue B, or later EASA approved revision.3. If no cracking is detected, repeat the inspection of the tail spring support in accordance with PART I of EXTRA Service Bulletin No. SB-300-2-97 Issue B, or later EASA approved revision.Note 1: Modification of the tail spring support structure in accordance with Requirement 2 terminates the Requirement 3 repeat inspections of this Directive.Note 2: EASA AD 2009-0160 refers. |\n| Compliance:    | 1. Before further flight after 28 July 2009.2. Before further flight.3. Within 50 flight hours or at the next scheduled 50-hour inspection after 28 July 2009, whichever occurs first. Inspect thereafter at intervals not to exceed 50 flight hours; until modification of the tail spring support structure as instructed in PART II of EXTRA Service Bulletin No. SB-300-2-97 Issue B, or later EASA approved revision.                                                                                                                                                                                                                                                                                                                        |\n|                | This Airworthiness Directive becomes effective on 28 July 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n\n| Background: | The manufacturer advised that the combination of a redesigned tail spring support with a stiffer tail spring and rough field operations has led to cracks in the tail spring support mounting base. Cracks have also been reported on aircraft already compliant with PART II of SB-300-2-97 Issue A. For the reasons stated above, this Directive mandates instructions for recurring inspections and modification in the area of the tail spring support in order to prevent separation of the tail landing gear, which could result in serious damage to the aircraft during landing. |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n23 July 2009","sortOrder":0},{"sectionNumber":"AD/EXTRA/10","sectionType":"part","heading":"AD/EXTRA/10","content":"## AD/EXTRA/10","sortOrder":1},{"sectionNumber":"Fuselage Structure - Tail Spring Support","sectionType":"part","heading":"Fuselage Structure - Tail Spring Support","content":"## Fuselage Structure - Tail Spring Support","sortOrder":2},{"sectionNumber":"10/2009 DM","sectionType":"part","heading":"10/2009 DM","content":"## 10/2009 DM","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with focused, original intent: address a specific structural defect in specific aircraft models. The scope remains tightly constrained to the tail spring support issue as originally identified."},"complexity_factors":["Short, single-purpose document (1 page)","Only 3 defined requirements with clear conditional logic (if crack found → modify; if no crack → repeat inspect)","Cross-references to external manufacturer service bulletin (SB-300-2-97 Issue B) and EASA AD 2009-0160, but these are standard aviation references","Simple applicability table with serial number ranges","No nested exceptions or complex definitions section","Compliance dates are straightforward calendar or flight-hour based"],"plain_english_summary":"This mandatory CASA Airworthiness Directive affects Extra EA‑300/L and EA‑300/200 aeroplanes with specified serial numbers, addressing cracks in the tail spring support that can lead to tail landing gear separation. Owners must inspect the support per the manufacturer’s service bulletin before further flight after 28 July 2009, repair or modify immediately if cracks are found, and continue 50‑hour repetitive inspections until the modification is completed to prevent catastrophic failure."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive stays within the original safety purpose: to identify and remedy cracking at the tail spring support to prevent tail landing gear separation. It requires inspections and, if necessary, a specified structural modification. There is no evidence in the text that the directive broadened beyond that original technical safety objective; instead it prescribes inspection frequency, corrective action, and termination of the recurring inspections once the modification is completed."},"complexity_factors":["Short, single‑issue directive focused on one structural area (tail spring support).","Three clear requirements with straightforward conditional logic (inspect; if cracked modify; if not, repeat inspection).","References to one external document: EXTRA Service Bulletin SB-300-2-97 Issue B (or later EASA‑approved revision) — reliance on an external technical document adds dependency but not internal complexity.","One termination clause: completing PART II cancels the recurring inspection requirement (single nested exception).","Applicability limited to specific serial numbers, reducing scope complexity.","Cross‑reference to EASA AD 2009‑0160 (external regulatory cross‑reference)."],"plain_english_summary":"**What this rule does (mechanics)**\n\n- Requires owners/operators of specified Extra EA-300 series aeroplanes to inspect the tail spring support (the structural area that mounts the tail landing gear spring) following the instructions in PART I of EXTRA Service Bulletin SB-300-2-97 Issue B (or a later EASA‑approved revision).\n- If an inspection finds a crack, the operator must modify the tail spring support in accordance with PART II of the same service bulletin (or later EASA‑approved revision).\n- If no crack is found, the operator must repeat the inspection at intervals not exceeding 50 flight hours until the modification in PART II is carried out.\n- Once the required modification (PART II) is completed, the repeat inspections required by this directive stop (i.e. the modification terminates the inspection requirement).\n\n**Who this affects**\n\n- Aircraft owners/operators and maintenance organisations responsible for Extra EA‑300/L and EA‑300/200 aeroplanes listed in the applicability table (specific serial numbers are covered). The directive is not a voluntary recommendation — it is an airworthiness directive, so compliance is mandatory for those aircraft.\n\n**Key compliance timings**\n\n- Initial inspection: must be done before the next flight after 28 July 2009 (i.e. immediately for aircraft subject to the directive).\n- If a crack is found: modification must be done before further flight.\n- If no crack is found: repeat inspections every 50 flight hours or at the next scheduled 50‑hour inspection after 28 July 2009, whichever is earlier, until the modification is completed.\n\n**Why it matters (stated purpose and practical effect)**\n\n- The manufacturer reported that a combination of a redesigned mounting, a stiffer tail spring and rough field operations has caused cracking at the tail spring support mounting base. Cracks can lead to separation of the tail landing gear and serious landing damage.\n- Mechanically, the directive forces inspection and, where cracking is present (or to eliminate the need for repeated inspections), structural modification intended to stop cracks developing further and to prevent possible landing gear separation.\n\n**Who pays, who decides, and what behaviour changes**\n\n- Owners/operators pay for the inspections and any required modification work, and they lose aircraft availability during that work. Maintenance organisations perform the inspections and modifications to the standard specified in the service bulletin.\n- The Civil Aviation Safety Authority (via its delegate) has mandated the requirement; operators must follow the specified service bulletin or a later EASA‑approved revision.\n- Behaviour changes: operators must institute a recurring 50‑hour inspection regime for affected aircraft until the modification is carried out; if cracks are found they must ground the aircraft until modified.\n\n**Costs, incentives and trade-offs**\n\n- Direct costs: labour and parts for inspections and for the modification where required; aircraft downtime for the modification.\n- Benefit: reduced risk of tail‑gear separation and associated damage or loss during landing.\n- Trade‑off: recurring inspection costs and operational disruptions versus the one‑off cost of modifying the structure; the directive explicitly ends recurring inspections once modification is completed (reducing future inspection cost if owners choose to modify).\n\n**Implementation and compliance notes**\n\n- The directive requires following EXTRA Service Bulletin SB-300-2-97 Issue B or a later EASA‑approved revision. Using a later EASA‑approved revision is permitted but not other unspecified procedures.\n- The AD cross‑references EASA AD 2009‑0160.\n- The directive is limited to the serial numbers listed. Aircraft not listed are not subject to this directive unless otherwise stated.\n\n**Risks and practical considerations**\n\n- Operators in rough‑field environments may face higher inspection and modification likelihood because the manufacturer linked rough operations to the cracking.\n- If an operator delays modification to avoid one‑off cost, they will incur recurring inspection costs and operational risk of a crack being found and immediate grounding.\n- Enforcement and acceptability of alternative corrective actions depend on CASA/EASA approval; any deviation requires regulatory approval."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-extra-10-fuselage-structure-tail-spring-support","history":"/api/acts/ad-extra-10-fuselage-structure-tail-spring-support/history","analysis":"/api/acts/ad-extra-10-fuselage-structure-tail-spring-support/analysis","conflicts":"/api/acts/ad-extra-10-fuselage-structure-tail-spring-support/conflicts","importantCases":"/api/acts/ad-extra-10-fuselage-structure-tail-spring-support/important-cases","documents":"/api/acts/ad-extra-10-fuselage-structure-tail-spring-support/documents"}}